JPH06105449B2 - Graph display device - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a graph display device for displaying a function expression as a graph by a simple key operation.

[Prior Art and its Problems] Conventionally, in a small electronic computer such as a personal computer and a pocket computer, a program such as BASIC is created, and a graph is displayed by inputting data such as a functional expression and a numerical value. It is considered that the calculation result is displayed dot by dot on the display unit by inputting the calculation result or the calculation formula, and finally the graph is displayed.

However, among the above-mentioned small personal computers, pocket computers, and other small electronic calculators that display a graph by a program, it is necessary to build a program dedicated to the graph. The display could not be done easily. Further, in the case where the calculation result is displayed as a graph on the display unit one dot at a time, the display data is stored in the memory, so that it is impossible to specify the scaling of the graph.

[Object of the Invention] The present invention has been made in view of the above circumstances.
It is an object of the present invention to provide a graph display device capable of enlarging a display graph with a simple key operation.

[Points of the Invention] The present invention sets new input states in the range of the display graph by various key operations and designates two points on the screen of the display unit, so that the coordinate data of the designated two points is newly added. The display range is set, and a new graph display is executed in the newly set display range to enlarge the graph.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows its circuit configuration, and 11 is a key input section. The key input section 11 includes a numeric keypad 11a for inputting numerical data, a function key 11b for specifying calculation contents,
Function key 11c for inputting function data, X key 11d for inputting range data of enlargement / reduction X coordinate, Y key 11e for inputting range data of Y coordinate, coordinate data of display range of enlargement / reduction are displayed in blinking. Point (hereinafter "pointer"
Plot key 11f specified by the ()) and the enlargement / reduction A key (represented as "enlargement / reduction A" in the figure) for performing enlargement / reduction by inputting coordinate data of diagonal points of the display range 11
g, an enlargement / reduction B key (denoted as “enlargement / reduction B” in the figure) 11h for inputting range data and enlarging / reducing the range data using the X key 11d and the Y key 11e, and a blinking pointer on the coordinate axis. An expansion key 11i for moving and inputting range data of the display range for expansion and an execution key (represented as "EXE" in the figure) 11j for executing graph display are provided.
When these keys are operated, the key operation data is sent to the control unit 12. The control unit 12 controls the circuit according to the key operation data from the key input unit 11, and has a text display buffer 13 for storing the coordinate data of the display pointer of the graph and a graph display buffer 14 for storing the display data of the graph. Control data is sent to a calculation unit 15 for performing various calculations for displaying a graph, an execution pointer 16 for instructing execution of calculation for displaying a pointer, and a memory unit 17 constituted by a RAM and the like. This memory section 17
Is a graph expression register 17a for storing a function expression to be displayed in a graph, and Px registers 17b, P for storing coordinate data of diagonal points of enlargement / reduction input by operating the plot key 114.
y register 17c, P'x register 17d, P'y register 17
e, X register 1 for storing the X coordinate data of the display pointer
7f, Y register 17g, which also stores Y coordinate data, Xmin register 17h, which stores range data, Xmax register 1
7i, Ymin register 17j, Ymax register 17k, Xmemo register 17l for storing the value of X to be substituted into the functional expression, and Ymemo register 17m for similarly storing the value of Y are provided, and the calculation unit 15 is controlled by the control unit 12 And input / output data.
In addition to the memory unit 17, the calculation unit 15 includes a formula buffer 18 that stores functional formula data according to an instruction from the execution pointer 16.
Data is input and output to perform graph display, range change, calculation for the pointer and its coordinate data, and the calculation result is output to the text display buffer 13 and graph display buffer 14. Text display buffer 13
The coordinate data of the display pointer is stored in, and the display data of the graph and the pointer are stored in the graph display buffer 14, and the stored data is sent to the display unit 19. The display unit 19 is, for example, a vertically arranged liquid crystal display device.
It consists of a dot matrix of 96 dots × 96 dots horizontally, and has a text display buffer 13 and a graph display buffer.
The data from 14 displays the graph, the pointer on the graph line, the coordinate data of the pointer, etc.

Next, the operation of the above embodiment will be described. FIG. 2 shows the key operation and the state of the display section 19 corresponding to the key operation. First, the display section 19 shows a graph for the formula y = sin x as shown in FIG. Suppose the axis is displayed. This graph display is performed by inputting mathematical formulas and range data in advance by operating the ten keys 111, the function keys 112, and the function keys 113 of the key input unit 11. In this state, the data “y = sin x” of the above formula is input to the formula buffer 18, and the range data “−180” “180” in the X-axis direction is also stored in the Xmin register 17h and the Xmax register 17i. Range data "-1" and "1" in the Y-axis direction are input to the Ymin register 17j and the Ymax register 17k, respectively.

Here, as shown in Fig. 2 (2), coordinate data (30, 0.7)
Manipulate plot key 11f to enter
When "30", "," and "0.7" are keyed in with the 1a and function keys 11b and the execute key 11j is subsequently operated, the process of FIG. 3 is performed in response to the operation of the execute key 11j. That is, in the figure, first, in step A01, it is determined whether or not this is a plot command, that is, whether or not it is the operation of the execution key 11j after the operation of the plot key 11f. if,
If not, other processing is performed according to the contents of the key operated before the execution key 11j is operated, but here, the execution key 11j after the operation of the plot key 11f is executed.
Since it is an operation, it is determined to be a plot command, and the process proceeds to step A02. In step A02, Px register 17
The coordinate data input to b is stored in the P'x register 17d,
In addition, the coordinate data input to the Py register 17c is set to P ′.
The coordinate data is not yet input to the Px register 17b and the Py register 17c, so that the P'x register 17d and the P'y register 1 are transferred to the y register 17e.
No coordinate data transfer is input to 7e. Then, in step A02, based on the coordinate data (P'x, P'y) input to the P'x register 17d and P'y register 17e, the coordinates (P'x, P 'in the graph display buffer 14 are calculated in step A03. ′
The lighting signal is sent to the address at the position corresponding to y).
Here, as described above, the P'x register 17d,
Since no coordinate data is input to the P'y register 17e, no lighting signal is sent to the graph display buffer 14. Then plot key 11f as shown in step A04.
It is determined whether or not there is data input after the operation of. Since the coordinate data "30" has been input here, if it is determined that there is data, the process advances to step A05, and the plot key 1
It is determined whether the data “30” operated after 1f is “,”, that is, whether the input of the X coordinate data is omitted. The result of this determination is "No", and in the subsequent step A06, the coordinate data "30" operated next to the plot key 11f is input and set in the Px register 17b. Next, in step A07, the key input operated next to the “,” input following this coordinate data “30” is the execution key 11
It is determined whether or not j, that is, whether or not the input of Y coordinate data is omitted this time. The result of this determination is also "No", and in the following step A08, the coordinate data "0.7" operated next to that "," is input and set in the Py register 17c. This completes the input settings of the coordinate data specified by operating the plot key 11f, and then
At A09, the coordinate data (30, 0.7) set in the Px register 17b and the Py register 17c are input to the Xmemo register 17l and the Ymemo register 17m for displaying the pointer text.
Then, in step A10, the control unit 12 causes the Px register 17b, Py
The address in the graph display buffer 14 corresponding to the coordinate data input to the register 17c is selected, and the blinking data is sent to the selected address. Finally, in step A11, a display is made on the display unit 19 corresponding to the contents of the graph display buffer 14 and the text display buffer 13. Here, in the display unit 19, FIG.
In addition to the graph shown by, the dot at the position of coordinates (P'x, P'y), that is, (30, 0.7) is displayed as a pointer blinking, and Xmem is displayed as the coordinate display of this pointer.
The contents of the register 17l are sent to the text display buffer 13 and the character "X = 30" is displayed at the bottom of the screen.

Then, as shown in FIG. 2 (3), the coordinate data (30,
Operate the plot key 11f to input the coordinate data (60, 0.3) of the diagonal point for 0.7), and enter "60", ",""0.3" with the numeric keypad 11a and the function key 11b, and then When you operate the execution key 11j, this execution key 11j
The process of FIG. 3 is performed again for the operation of. That is, the coordinate data “30” input to the Px register 17b and the Py register 17c in FIG. 2 (2) in step A02 after it is determined to be a plot command in step A01.
"0.7" is P'x register 17d, P'y register respectively
Transferred to 17e. After that, the P'x register 17d,
Coordinate data “30” and “0.
Based on "7", a lighting signal is sent to the address of the position corresponding to the coordinate (30, 0.7) of the graph display buffer 14 in step A03. Then, in step A04, it is determined that there is data after the operation of the plot key 11f, and the process proceeds to step A05. If it is determined in step A05 that the data immediately after operating the plot key 11f is not ",", then in step A06 the data "60" immediately after operating the plot key f.
Is newly input to the Px register 17b. Then step A
In 07, it is determined that the data operated next to “,” is not the execution key 11j, the process proceeds to step A08, and the data “0.3” is newly input to the Py register 17c. At the next step A09, the contents of Px register 17b and Py register 17c are changed to Xmemo.
Transferred to register 17l, Ymemo register 17m, step A
At 10, the control unit 12 selects an address in the graph display buffer 14 corresponding to the coordinate data (60, 0.3) input to the Px register 17b and Py register 17c, and sends flashing data to the selected address. . And finally step A1
In 1, the display is made on the display unit 19 in correspondence with the contents of the graph display buffer 14 and the text display buffer 13. Here, in the display unit 19, the graph shown in FIG. 2 (1) and the coordinates (30,0.
7) The dot at the position is lit up and the dot at the coordinate (60,0.3) is flashing as a pointer, and the contents of the Xmemo register 17l are sent to the text display buffer 13 as the coordinate display of this pointer, and the screen is displayed. At the bottom, "X = 6
The character "0" is displayed as text.

Although not described in the above operation, if the execution key 11j is operated and the coordinate data is not input immediately after the operation of the plot key 11f in step A04, the plot of the pointer is set as the center point of the display unit 19. The coordinate data is omitted. Therefore, step A04 is followed by step A
In step 12, the calculation (Xmin + Xmax) / 2 is performed using the range data "Xmin" and "Xmax" in the X-axis direction input to the Xmin register 17h and Xmax register 17i, and the calculation result is displayed in the center of the display unit 19. The X coordinate data of the point is input and set in the Px register 17b. After that, the process proceeds to step A13, this time Ymin register 17j, Ymax
Range data in the Y-axis direction “Ymi
The calculation (Ymax + Ymin) / 2 using “n” and “Ymax” is performed, and the calculation result is input and set in the Py register 17c as Y coordinate data of the center point of the display unit 19. When the input of the Px register 17b and the Py register 17c is finished, the processes of the above steps A09 to A11 are performed and the display on the display unit 19 is performed. Also, in step A05 above, plot key 1
Even if it is determined that the key input immediately after the operation of 1f is ",", the X coordinate data input is omitted, so
The calculation shown in step A12 is performed, and the calculation result is used as the X coordinate data of the center point of the display unit 19 in the Px register.
After the input is set in 17b, the process goes to step A07. If it is determined in step A07 that the data entered immediately after the data “,” is the execution key 11j, it is determined that the Y coordinate data has been omitted, and the calculation in step A13 and the Py register 17c are performed. After making the settings in step A09-
The processing of A11 is performed and the display on the display unit 19 is performed.

After that, as shown in Fig. 2 (4), enlargement / reduction A key 11g
When is operated, the display graph is enlarged or reduced by the processing shown in FIG. That is, the enlargement / reduction A key 11g is for displaying a graph in which the area having two diagonal points designated by the operation of the plot key 11f is enlarged / reduced on the entire screen of the display unit 19, and in the processing, first,
As shown in B01, it is determined whether the X coordinate data input to the Px register 17b is larger than the X coordinate data input to the P'x register 17d. Here, since the value of the Px register 17b is "60" and the value of the P'x register 17d is "30", it is determined that the value of the Px register 17b is larger, and the process proceeds to step B02 and the Px register The X coordinate data "60" input to 17b is stored in the Xmax register 17i,
X coordinate data "3" input to the P'x register 17d
“0” is input and set in the Xmin register 17h as new X coordinate range data, and then the process goes to step B03.
On the contrary, if it is determined in step B01 that the X coordinate data input to the P'x register 17d is larger than the X coordinate data input to the Px register 17b, the process proceeds to step B04 and step B02. On the contrary, P'x register 17
Set the value of d to Xmax register 17i and the value of Px register 17b to Xmin.
The range data of the new X coordinate is input and set in the register 17h, and then the process goes to step B03. In step B03, in order to set the Y coordinate range data in the same manner as the above X coordinate range data setting, Py
The Y coordinate data input to the register 17c is P'y
It is determined whether or not it is larger than the Y coordinate data input to the register 17e. If it is determined that the value of the Py register 17c is larger than the value of the P'y register 17e, the value of the Py register 17c is stored in the Ymax register 17k and the P'y register 17e.
Is input to the Ymin register 17j as new Y coordinate range data. However, since the value of the Py register 17c is "0.3" and the value of the P'y register 17e is "0.7" here, it is determined that the value of the P'y register 17e is larger, and then step B07. Proceed to. In step B07, contrary to the above step B05, the value of the P'y register 17e is input to the Ymax register 17k and the value of the Py register 17c is input to the Ymin register 17j as new Y coordinate range data. Then, the data “0.7” is input to the Ymax register 17k and the data “0.3” is input to the Ymin register 17j.

This completes the setting of the new range data, and in the subsequent step B06, the formula data "y = sin x" of the graph stored in the graph formula register 17a is called to the arithmetic unit 15. In accordance with this called formula data, in the next step B08, the calculation unit 15 calculates the display data for creating a graph within the newly set range data, and the calculation result is stored in the graph display buffer 14. Input sequentially. Then, when the input to the graph display buffer 14 is completed, an enlarged graph as shown in the drawing is displayed on the display unit 19 by the display data input to the graph display buffer 14 in step B09. The processing for the key 11g operation ends.

The operation of enlarging / reducing the display graph by operating the enlarging / reducing B key 11h will be described below in response to the operation of enlarging / reducing the displayed graph by operating the enlarging / reducing A key 11g. The enlargement / reduction B key 11h is pressed in accordance with the operation of the X key 11d and the Y key 11e.
The setting of coordinate range data and the setting of Y coordinate range data are performed separately. That is, when the display unit 19 is in the display state as shown in FIG. 2 (1), the X key 11d is operated as shown in FIG. 2 (5) to specify the input of the range data of the X coordinate. When the numeric keypad 11a and the function key 11b are used to key in "-30", "," and "60" and then the enlargement / reduction B key 11h is operated, the processing shown in FIG. 5 is performed. This is the first step C0
In step 1, the control unit 12 performs key sampling and determines that the operation key is the enlargement / reduction B key 11h.
It is determined whether or not the key operated at the beginning of the input is the X key 11d or the Y key 11e. If it is determined that the operation key is neither the X key 11d nor the Y key 11e, the X coordinate and the Y coordinate are not specified, and the enlargement / reduction B key 11h cannot enlarge or reduce the display graph. ,
An error will occur. If it is determined that the operation key is the X key 11d or the Y key 11e, then in step C03,
It is determined whether the operation key is the X key 11d. Here, the operation key is the X key 11d, so the determination result is "Y
es ”, and then proceeds to step C04, in which of the two numerical data input after the X key 11d, the larger numerical data is stored in the Xmax register 17i and the smaller numerical data is stored in the Xmax register 17i.
Input to the min register 17h as X coordinate range data. Therefore, the numerical data "60" is stored in the Xmax register 17i and Xmi
Numerical data "-30" is input and set to the n register 17h. In step C03, the operation key is X key 1
If it is judged that it is not 1d, the operation key is Y key 11e
Therefore, proceed to step C05,
Of the two numerical data input after the operation of the Y key 11e, the larger numerical data is input to the Ymax register 17k and the smaller numerical data is input to the Ymin register 17j as Y coordinate range data.

When the range data input settings are complete, the next step is C06.
At, the function formula data “y = sin x” of the graph stored in the graph formula register 17a is called up by the arithmetic unit 15.
According to this called function expression data, the next step C0
In step 7, the calculation unit 15 calculates the display data for creating a graph within the newly set range data. Here, the X-coordinate range data “−30” and “60” are stored in the Xmin register 17h and the Xmax register 17i, respectively, and Y is stored in the Ymin register 17j and the Ymax register 17k.
The coordinate range data "-1" and "1" have been input, and the calculation results in this range data are sequentially input to the graph display buffer 14. Then, when the input to the graph display buffer 14 is completed, the graph enlarged in the X-axis direction as shown in the display unit 19 is displayed by the display data input to the graph display buffer 14 in step C08. Thus, the processing for the operation of the enlargement / reduction B key 11h is completed.

Next, in order to perform enlargement / reduction in the Y-axis direction this time, as shown in FIG. 2 (6), the Y key 11e is operated to specify the input of the range data of the Y coordinate, and the ten keys 11a and the function keys 11b are used. When "0", "," and "1" are keyed in and the enlarging / reducing B key 1h is subsequently operated, the processing shown in FIG. 5 is performed again. That is, first, at step C01, it is determined that the operation key is the enlargement / reduction B key 11h, then at step C02, it is determined that the key operated at the beginning of the input is the X key 11d or the Y key 11e, and then step C03. Then, it is determined that the operation key is not the X key 11d, and the process proceeds to step C05. Of the two numerical data “0” and “1” input after the operation of the Y key 11e in step C05, the larger numerical data “1” is stored in the Ymax register 17k and the smaller numerical data “0” is stored in Ymin. Y in register 17j
Input and set as coordinate range data.

When the range data input settings are complete, the next step is C06.
At the step C07, the function formula data "y = sin x" of the graph stored in the graph formula register 17a is called by the calculation unit 15, and the next step C07 is executed according to the called function formula data.
Then, the calculation unit 15 calculates the display data for creating the graph within the newly set range data. Here, the X-coordinate range data “−30” and “60” are stored in the Xmin register 17h and the Xmax register 17i, respectively, and Y is stored in the Ymin register 17j and the Ymax register 17k.
Coordinate range data “0” and “1” have been input,
The calculation results within this range data are sequentially input to the graph display buffer 14. And the graph display buffer
At the time when the input to 14 is completed, the graph enlarged in the Y-axis direction as shown in the drawing is displayed on the display unit 19 by the display data input to the graph display buffer 14 in step C08. The processing for the B key 11h operation is terminated.

In the above example, only the operation of enlarging the display graph has been described, so the operation of reducing the display graph will be described below. FIG. 6 shows the key operation and the display state of the display section 19 corresponding to the key operation. First, as shown in FIG. 6 (1), a graph is displayed on the display section 19 in the same state as in FIG. 2 (1). It is supposed to be displayed. Here, the function buffer data “y = sin x” is input to the mathematical formula buffer 18, and the Xmin direction range data “−” is input to the Ymin register 17h and the Ymax register 17i.
180 "and" 180 ", and range data" -1 "and" 1 "in the Y-axis direction are input to the Xmin register 17j and the Ymax register 17k, respectively.

Here, as shown in FIG. 6 (2), coordinate data (-360,
2) Operate the plot key 11f to input, and use the numeric keypad 11a and the function key 11b to select "-360"",".
When "2" is keyed in and the execute key 11j is subsequently operated, the process of FIG. 3 is performed in response to the operation of the execute key 11j. In the figure, first, in step A01, it is determined that this is a plot command, and then in step A02.
The coordinate data input to the Px register 17b to P ′.
The coordinate data input to the x register 17d and the Py register 17c are transferred to the P'y register 17e.
Here, since the coordinate data has not been input to the Px register 17b and the Py register 17c, the P'x registers 17d and P '
No coordinate data is transferred and input to the y register 17e. Then, in step A03, a lighting signal is sent to the address of the position corresponding to the coordinates (P'x, P'y) of the graph display buffer 14. Here, as stated above, P'x
Since no coordinate data is input to the registers 17d and P'y register 17e, no lighting signal is sent to the graph display buffer 14. Then in step A04 plot key 1
If it is determined that there is data input after the operation of 1f, it proceeds to step A05, and it is determined whether the data "-360" operated next to the plot key 11f is ",". The result of this determination is "No", and in the subsequent step A06, the coordinate data "-360" operated next to the plot key 11f is input and set in the Px register 17b. Next, at step A07, it is judged whether or not the key input operated after "," which is subsequently input to the coordinate data "-360" is the execution key 11j. The result of this judgment is also "No", and in the subsequent step A08, the coordinate data "2" operated next to that "," is input and set in the Py register 17c. This completes the input setting of the coordinate data specified by operating the plot key 11f, and the coordinate data (-360,2) set in the Px register 17b and Py register 17c is displayed as a pointer text in the following step A09. To Xmemo
Input to register 10l and Ymemo register 17m. Thereafter, in step A10, the control unit 12 selects an address in the graph display buffer 14 corresponding to the coordinate data input to the Px register 17b and Py register 17c, and sends the blinking data to the selected address. However, in this case, the graph is reduced, and the coordinate data (-36
Since there is no address in the graph display buffer 14 corresponding to (0, 2) and its selection is impossible, no blinking data is sent to the graph display buffer 14. And
Finally, in step A11, a display is made on the display unit 19 corresponding to the contents of the graph display buffer 14 and the text display buffer 13. Here, in the display unit 19, the sixth
In addition to the graph shown in FIG. 1A, the contents of the Xmemo register 17l are sent to the text display buffer 13 as the coordinate display of this pointer, and the character "X = -360" is displayed at the bottom of the screen.

Then, as shown in FIG. 6 (3), the coordinate data (-36
Operate the plot key 11f to input the coordinate data (360, -2) of the diagonal point with respect to (0,2)
If you input "360", ",""-2" with the function key 11b and then press the execute key 11j, the execution key 1
Again in response to the operation of 1j in FIG. 3, after it is judged in step A01 that it is a plot instruction, in step A02, the Px register 17b and the Py register 1 in FIG.
The coordinate data "-360" and "2" input to 7c are transferred and input to the P'x register 17d and P'y register 17e, respectively. Then, based on the coordinate data "-360" and "2" input to the P'x register 17d and P'y register 17e, the position corresponding to the coordinate (-360,2) of the graph display buffer 14 is determined in step A03. A lighting signal is sent to the address, but since such an address does not exist, the lighting data is not stored in the end. Then, in step A04, it is determined that there is data after the operation of the plot key 11f, and the process proceeds to step A05.
If it is determined in step A05 that the data immediately after the operation of the plot key 11f is not ",", then in step A06, the data "36" immediately after the operation of the plot key 11f is
"0" is newly input to the Px register 17b. Subsequently, in step A07, it is determined that the data operated next to "," is not the execution key 11j, and the process proceeds to step A08, in which the data "-2" is newly input to the Py register 17c. In the next step A09, the contents of Px register 17b and Py register 17c are changed to Xme.
It is transferred to the mo register 17l and the Ymemo register 17m, and in step A10, the control unit 12 sets the address in the graph display buffer 14 corresponding to the coordinate data (360, -2) input to the Px register 17b and the Py register 17c. No attempt is made to make a selection, but there is no such address, so no selection is made and therefore no subsequent flashing data is sent. Finally, in step A11, the graph display buffer 1
4 and the display unit 1 corresponding to the contents of the text display buffer 13
The display will be on 9. Here, in the display unit 19,
The graph shown in FIG. 6 (1) and the contents of the Xmemo register 17l as the coordinate display of the pointer not displayed are sent to the text display buffer 13 and the character "X = 360" is displayed at the bottom of the screen.

After that, as shown in Fig. 6 (4), enlargement / reduction A key 11g
When is operated, the display graph is enlarged or reduced by the processing shown in FIG. That is, first, as shown in step B01, it is determined whether or not the X coordinate data input to the Px register 17b is larger than the X coordinate data input to the P'x register 17d. Where Px register 17b
Is "360" and the value of the P'x register 17d is "-36".
Since it is "0", it is determined that the value of the Px register 17b is larger, and the process proceeds to step B02, where the X coordinate data "360" input to the Px register 17b is stored in the Xmax register 17i and the P'x register 17d. X coordinate data "-3
"60" is input and set in the Xmin register 17h as new X coordinate range data, and the process goes to step B03. In step B03, the Y coordinate data input to the Py register 17c is input to the P'y register 17e in order to set the Y coordinate range data in the same manner as the setting of the X coordinate range data. It is determined whether or not it is larger than the Y coordinate data. Here, the value of the Py register 17c is "-2" and the value of the P'y register 17e is "2".
Therefore, it is determined that the value of the P'y register 17e is larger, and the process proceeds to step B07. In step B07,
The value "2" in the P'y register 17e is set in the Ymax register 17k and Py
The value "-2" in the register 17c is input and set in the Ymin register 17j as new range data of the Y coordinate. When the setting of the range data is completed, in the subsequent step B06, the function formula data “y = sin x” of the graph stored in the graph formula register 17a is called by the arithmetic unit 15, and according to the called function formula data, In the next step B08, the calculation unit 15 calculates the display data for creating the graph within the newly set range data. here,
X-coordinate range data “−360” and “360” are stored in the Xmin register 17h and Xmax register 17i, and Y-coordinate range data “-2” and “2” are stored in the Ymin register 17j and Ymax register 17k. Is input, and the calculation results in this range data are sequentially input to the graph display buffer 14. Then, when the input to the graph display buffer 14 is completed, a reduced graph as shown in the drawing is displayed on the display unit 19 by the display data input to the graph display buffer 14 in step B09. The reduction processing of the display graph corresponding to the reduction A key 11g operation is ended.

Next, the expansion operation of the display graph using the expansion key 11i will be described with reference to FIGS. 7 and 8. Fig. 7 shows enlargement key 11
The operation of keys including i and the state of the display section 19 corresponding to the operation are shown. First, as shown in FIG. 7 (1), a graph is displayed on the display section 19 in the same state as in FIG. 2 (1). And the coordinate axes are displayed. Here, the function formula data “y = sin x” is input to the formula buffer 18, and the X-axis direction range data “−180” and “180” are stored in the Xmin register 17h and Xmax register 17i. Ymin register 17
j, Ymax register 17k stores Y-axis range data "-
"1" and "1" are input respectively.

When the enlargement key 11i is operated as shown in FIG. 7 (2), the process shown in FIG. 8 is performed in response to the operation of the enlargement key 11i. That is, in FIG.
It is determined whether or not the X-axis is displayed with D01. Since the X-axis is displayed here, the next step
Proceeding to D02, the display address corresponding to the left end of the X-axis of the display unit 19 in the graph display buffer 14 is selected, and the blinking data is sent to that address. The left end of the X-axis of the display unit 19 is represented by coordinate data (Xmin, 0) by the data "Xmin" stored in the Xmin register 17h. In this case, the coordinate is (-180,0). When the blinking data is written in the address of the coordinate position, the pointer is displayed on the display unit 19 according to the blinking data, and the cursor key or the X key 11d for designating the next movement in the left and right direction as shown in the following step D03. It will be in the standby state for key input of.

If it is determined in step D01 that the X-axis is not displayed, the process proceeds to step D04 and the Xmin register 17
The coordinate data (Xmin, Ymi) is also obtained by using the value closer to “0” of the j and Xmax registers 17k, for example, “Ymin”.
The blinking data is written in the address corresponding to the left end of the display unit 19 in the graph display buffer 14 represented by n), the pointer is displayed on the display unit 19 according to the blinking data, and then the process goes to step D03.

While waiting for key input in step D03,
As shown in Fig. (3), when the cursor key that specifies the rightward movement in the function key 11b is operated, this key input proceeds to step D05, and whether this key input is the X key 11d operation or not. to decide. Here, since this key input is based on the cursor key operation for designating the rightward movement, the determination result is "No", and the process proceeds to step D06. In step D06, the plot point of the pointer is calculated and set according to the moving direction of the operated cursor key. Here, calculation of the plot points of the pointers, the formula X ₁ = (Xmax-Xmin) / number of dots (the number of dots, for example in this case 95), based on the dot "X _1" which is calculated from the movement of the cursor keys If the direction is right, plot point = current point + X _{1 If} the cursor key movement direction is left, plot point = current point -X ₁ The X coordinate can be obtained by an arithmetic expression (Y coordinate is “0”). ), The plot display is executed in the following step D07 in accordance with the plot point obtained by this calculation result, and the key standby state of step D03 is again established.

In this way, the cursor key for designating the rightward movement is operated a plurality of times, and when the pointer is displayed at the desired position by repeating the operations of steps D03, D05 to D07, the first X key 11d is moved to the range. When operated for setting data, this operation determines that the operation key is the X key 11d in step D05, and then proceeds to step D08. In step D08, it is determined whether or not the operation of the X key 11d is the first operation. Since it is the first operation here, the process proceeds to step D09, and the X coordinate of the current plot point of the pointer. The data is input and set in the P'x register 17d, and the key input standby state is again entered in step D03.

Then, as shown in FIG. 7 (4), the cursor key for designating the rightward movement is again operated a plurality of times, and the above step D0
3. Repeat the operation of D05 to D07 to move the pointer to the right. In this case, you may operate the cursor key which moves a pointer to the left.

Then, when the pointer is displayed at the desired position, the second X key 11d is operated for setting the range data as shown in FIG. 7 (5), and this operation causes the operation in step D05. It is determined that the key is the X key 11d, and the process proceeds to step D08. If it is determined in step D08 that this X key 11d has not been operated for the first time, the process proceeds to step D10, and the X at the plot point of the current pointer is set.
Input the coordinate data to the Px register 17b. Then, in step D11, P'x set in step D09 is set.
The value of register 17d is the Px register set in step D10.
Judge whether it is smaller than the value of 17b. In this case, P '
Since the value of the x register 17d is smaller than the value of the Px register 17b, next, in step D12, the value of the Px register 17b is set to Xmax.
The value of the P'x register 17d is set to the register 17i by the Xmin register.
Transferred to 17h as X coordinate range data,
Input settings. When it is determined in step D11 that the value of the P'x register 17d is not smaller than the value of the Px register 17b, the second plot point is in the negative direction rather than the first plot point, In other words, it is located to the left, and then the process proceeds to step D13, where the value of the P'x register 17d is set to the Xmax register 17 contrary to step D12.
In i, the value of the Px register 17b is transferred to the Xmin register 17h as the range data of the X coordinate, and the input is set.
When the setting of the new X coordinate range data is completed, next, in step D14, the mathematical formula data stored in the graph formula register 17a, the new X coordinate range data stored in the Xmin register 17h and the Xmax register 17i, and the Ymin register 17j. , X
The display data is calculated by the calculation unit 15 by the range data of the Y coordinate stored in the max register 1k, the calculation result is sent to the graph display buffer 14, and as a result, the enlarged graph is displayed on the display unit 19. At the same time, as shown in step D15, it is determined whether or not the Y axis is displayed on the graph of the display unit 19. In this case, since the Y-axis is displayed, the process proceeds to step D16, and the displayed Y-axis is displayed.
Blinking data is written at the address of the position of the graph display buffer 14 corresponding to the upper end of the axis, that is, the coordinates (0, Ymax), the pointer is displayed on the display unit 19 according to the blinking data, and the subsequent step D17 is shown. Cursor key or Y key 11e to specify the up / down movement as shown below
It will be in the standby state for key input of.

If it is determined in step D15 that the Y-axis is not displayed, the process proceeds to step D18 and the Xmin register 17
Coordinate data (Xmin, Ymax) using the value closer to "0" in either h or Xmax register 17i, for example, "Xmin"
The blinking data is written in the address corresponding to the upper end of the display unit 19 in the graph display buffer 14 represented by
The pointer is displayed according to the blinking data, and then the process goes to step D17.

While waiting for the key input in step D17,
As shown in Fig. 6 (6), when the cursor key for instructing the downward movement in the function key 11b is operated, the process advances to step D19 by this key input, and it is determined whether this key input is by the Y key 11e operation. To do. Here, since this key input is based on the cursor key operation for designating the downward movement, the determination result is "No", and the process proceeds to step D20. In step D20, the plot point of the pointer is calculated and set according to the moving direction of the operated cursor key. Here, the calculation of the plot point of the pointer is performed by moving the cursor key based on the dot unit “Y ₁ ” calculated from the formula Y ₁ = (Ymax−Ymin) / number of dots (the number of dots is 63 in this case, for example). If the direction is up, plot point = current point + Y _{1 If} the cursor key movement direction is down, plot point = current point -Y ₁ The Y coordinate can be obtained by an arithmetic expression (X coordinate is “0”). ), The plot display is executed in the following step D21 in accordance with the plot point obtained by this calculation result, and the key waiting state of step D17 is again established.

In this way, the cursor key for designating the downward movement is operated multiple times, and when the pointer is displayed at the desired position by repeating the operations of steps D17 and D19 to D21, the first Y key 11e is moved to the range. When operated for setting data, this operation determines that the operation key is the Y key 11e in step D19, and the process proceeds to step D22. In step D22, it is determined whether or not the operation of the Y key 11e is the first operation. Since it is still the first operation here, the process proceeds to step D23, and the Y coordinate of the plot point of the current pointer. The data is input and set in the P'y register 17e, and the key input standby state is again entered in step D17.

Then, as shown in FIG. 7 (7), the cursor key for designating the downward movement again is operated a plurality of times to perform the above step D1.
7. Repeat the operation of D19 to D21 to move the pointer downward. In this case, the cursor key for moving the pointer upward may be operated.

Then, when the pointer is displayed at the desired position, the second Y key 11e is operated for setting the range data as shown in FIG. 7 (8), and this operation is performed in step D19. It is determined that the key is the Y key 11e, and the process proceeds to step D22. If it is determined in step D22 that the Y key 11e is not operated for the first time, the process proceeds to step D24, and the Y coordinate data of the plot point of the current pointer is input and set in the Py register 17c. Then, in step D25, P ′ set in step D23 is set.
It is determined whether the value of the y register 17e is smaller than the value of the Py register 17c set in step D24. in this case,
Since the value of the P'x register 17d is not smaller than the value of the Px register 17b, next, in step D26, the P'y register 1
Set the value of 7e to Ymax register 17k and the value of Py register 17c to Ymin.
The data is transferred to the register 17j as Y-coordinate range data and set as input. In step D25, P '
If it is determined that the value in the y register 17e is smaller than the value in the Py register 17c, the second plot point will be located in the plus direction, that is, the upper direction than the first plot point. Then, proceed to step D27, and conversely to step D26, set the value of Py register 17c to Ymax register 17k.
Then, the value of the P'y register 17e is transferred to the Ymin register 17j as the Y coordinate range data, and is input and set. When the setting of the range data of the new Y coordinate is completed in this way, finally, in step D28, the graph type register 1
Numerical data stored in 7a, new Y coordinate range data stored in Ymin register 17j, Ymax register 17k, and Xmi
n17h, the display data is calculated by the calculation unit 15 by the range data of the X coordinate stored in the Xmax register 17i, the calculation result is sent to the graph display buffer 14, and the result is displayed on the display unit.
The graph enlarged to 19 is redisplayed, and the enlargement key 11i
The process of enlarging the display graph accompanying the specification of range data on the display coordinate axes by the operation is terminated. Note that when this enlargement key 11i is used, the range data is specified only on the coordinate axes of the display graph, so it is not possible to set the range that is not displayed as range data, and therefore the display graph should be reduced. I can't.

As described above, according to the present invention, by designating two points on the screen of the display unit, a new display range is set from the coordinate data of the designated two points, and a new display range is set in this range. Since a large graph is created and displayed in an enlarged manner, it becomes possible to execute an enlarged display of a necessary portion of the graph by an extremely simple operation.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a block diagram showing a circuit configuration, and FIG. 2 is an enlarged display of a graph of a display section by key operation and corresponding first and second methods. FIG. 3 is a flowchart showing a state, FIG. 3 is a flowchart showing a process for an execution key operation, FIG. 4 is a flowchart showing a process for an enlargement / reduction A key operation, and FIG. 5 is an enlargement / reduction B.
FIG. 6 is a flowchart showing a process for a key operation, FIG. 6 is a view showing a key operation and a state in which a graph is reduced and displayed on the display unit by the first method corresponding thereto, and FIG. 7 is a key operation and a third method corresponding thereto. FIG. 8 is a diagram showing a state of enlarged display of a graph on the display unit, and FIG. 8 is a flowchart showing a process for operating an enlarge key. 11 …… Key input section, 11a …… Numeric keypad, 11b …… Function key, 11c …… Function key, 11d …… X key, 11e…
… Y key, 11f …… Plot key, 11g …… Enlargement / reduction A key, 11h …… Enlargement / reduction B key, 11i …… Enlargement key, 11j…
… Execution key, 12… Control unit, 13… Text display buffer, 14… Graph display buffer, 15… Arithmetic unit, 16…
Execution pointer, 17 ... Memory part, 17a ... Graph expression register, 17b ... Px register, 17c ... Py register, 17d ...
... P'x register, 17e ... P'y register, 17f ... X
Register, 17g …… Y register, 17h …… Xmin register,
17i …… Xmax register, 17j …… Ymin register, 17k …… Y
max register, 17l …… Xmemo register, 17m …… Ymemo register, 18 …… formula buffer, 19 …… display section.

Continuation of front page (56) Reference JP-A-50-6380 (JP, A) JP-A-54-51752 (JP, A) JP-A-52-116050 (JP, A) JP-A-57-41731 (JP , A) JP 57-203127 (JP, A) JP 54-98532 (JP, A) The world of mathematics drawn by a microcomputer, Mitsuo Morimoto, Hyundai Mathematics Co., 1984-4-15, P9-15

Claims (1)

[Claims] 1. Xmin, X on a dot matrix type display screen
Display means having a rectangular display area in which the values of max, Ymin, and Ymax are coordinate values at both ends of the display limit in the X-axis direction and the Y-axis direction, respectively, and the size of the display screen is fixed; Display range storing means for storing the minimum value Xmin and the maximum value Xmax, and the minimum value Ymin and the maximum value Ymax in the Y-axis direction, a function formula storing means for storing the input function formula, and a value of X in the display range. Minimum value Xmin stored in the storage means
To a maximum value Xmax at predetermined intervals, and by substituting it into the function formula stored in the function formula storage unit, the calculation unit sequentially calculates the value of Y, and the X-axis stored in the display range storage unit. Direction minimum Xm
in, maximum value Xmax, minimum value Ymin in Y-axis direction, maximum value Ymax
Are the minimum and maximum coordinate values of the display area in the X-axis direction and the Y-axis direction, respectively.
A graph creating means for plotting the value of Y as the (X, Y) coordinate point in the display area, and two diagonal points newly set as the display target range on the graph screen displayed in the display area are designated. A new minimum value Xmin and maximum value Xmax in the X-axis direction and new minimum value Ymin and maximum value Ymax in the Y-axis direction are determined in association with the specification means and the coordinate data of the two points specified by the specification means. A display range changing means set in the display range storing means, and a new display target range set by the display range changing means is made to coincide with the entire display area, and the calculating means and the graph creating means are operated. A graph display device characterized in that a new graph can be created.