JPH10161981A - Device and method for displaying graph, and medium recording graph display program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an operator to display graph while thinking the orbit of graph corresponding to an inputted function expression at a graph display device for displaying the graph at electronic equipment provided with a calculation function. SOLUTION: When a graph function expression is inputted and stored in a function expression data register and an 'OK' key 12e is operated, graph data corresponding to the inputted function expression are plotted and stored in a graph data register and these graph data are displayed on a liquid crystal display part 13 for each display dot successively from the minimum value side of X coordinate to the maximum value side, for example. When a 'stop' key 12f is operated at any arbitrary graph plotting display position, the graph plotting display processing up to the moment is stopped in the middle and held and when the 'OK' key 12e is operated, this graph plotting display processing is started again so that the graph data can be continuously displayed over much wider coordinate range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention has a calculation function,
The present invention relates to a graph display device for displaying a graph in an electronic device, a graph display method, and a medium recording a graph display program.

[0002]

2. Description of the Related Art Conventionally, for example, in an electronic computer having a function calculation function, when a function expression is input, there is a type which draws and displays a graph corresponding to the input function expression. That is, when a desired function formula is input, the input function formula is stored, a coordinate range on the display screen is set, and each variable value according to the coordinate range is substituted into the stored function formula. Then, when the solution is obtained, the corresponding graph is drawn and displayed.

That is, in a graph display function of a conventional computer, when a function expression of a graph is input, a graph corresponding to the input function expression is immediately drawn and displayed.

[0004]

However, the graph display function of the above-mentioned conventional computer merely renders and displays the graph in accordance with the input function formula. When used as an educational computer, the learner can see the corresponding graph on the display immediately after entering the function formula, so what kind of trajectory will the graph corresponding to the input function formula become? However, there is a problem that the graph cannot be drawn and displayed while the learner considers itself.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and enables an operator to display a graph corresponding to an input function expression while considering what kind of trajectory the graph will be. It is an object to provide a graph display device, a graph display method, and a medium recording a graph display program.

[0006]

That is, a graph display device according to a first aspect of the present invention comprises: an expression input unit for inputting function expression data; and a function expression input by the expression input unit within a specified range. It is characterized by comprising a graph creating means for creating graph data of data, and a graph partial display means for displaying a part of the graph data created by the graph creating means.

That is, in the graph display device according to the first aspect of the present invention, graph data corresponding to the function expression data input by the expression input means is created, and a part of the created graph data is displayed. Thus, the operator can consider what trajectory the graph corresponding to the input expression will take.

A graph display device according to a second aspect of the present invention is the graph display device according to the first aspect, wherein the graph partial display means corresponds to the function expression input by the expression input means. And a graph partial display means for displaying only coordinate points corresponding to an arbitrary designated point of the graph data to be displayed.

That is, in the graph display device according to the second aspect of the present invention, only the coordinate points corresponding to any designated points of the graph data corresponding to the function expression input by the expression input means are displayed. Can look at the coordinate point corresponding to the arbitrary designated point and consider what kind of trajectory the graph corresponding to the input expression takes.

A graph display device according to a third aspect of the present invention is the graph display device according to the first aspect, wherein the graph partial display means corresponds to a function expression input by the expression input means. A graph partial display means for displaying only coordinate points corresponding to singular points of the graph data to be displayed.

That is, in the graph display device according to claim 3 of the present invention, only the coordinate points corresponding to the singular points of the graph data corresponding to the function expression input by the expression input means are displayed. By looking at the coordinate points corresponding to the singular points, it is possible to consider what kind of trajectory the graph corresponding to the input expression has.

A graph display device according to a fourth aspect of the present invention is the graph display device according to the first aspect, wherein the graph partial display means corresponds to a function expression input by the expression input means. Graph display means for sequentially displaying graph data to be displayed in a predetermined coordinate direction, and display stop means for stopping the sequential display operation of the graph data by the graph display means at an arbitrary time. It is characterized by.

That is, in the graph display device according to the fourth aspect of the present invention, the graph data corresponding to the function expression input by the expression input means is sequentially displayed in a predetermined coordinate direction, and the graph data is sequentially displayed. Since the operation is stopped at an arbitrary point, the operator can see the graph corresponding to the input expression to an arbitrary range and think what kind of trajectory the entire graph will take.

According to a fifth aspect of the present invention, there is provided a graph display device comprising: a formula input means for inputting a function formula; a handwritten data display means for drawing and displaying a trajectory accompanying a handwriting operation;
A graph display unit for displaying graph data corresponding to the function expression input by the expression input unit on the display screen of the handwritten locus displayed by the handwritten data display unit.

That is, in the graph display device according to claim 5 of the present invention, the graph data corresponding to the function expression input by the expression input means is superimposed on the display screen of the handwritten locus displayed by the handwriting data display means. Since it is displayed, the graph corresponding to the input function formula considered by the operator can be compared and displayed with the correct graph.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an electronic circuit of an electronic computer according to an embodiment of the graph display device of the present invention.

This computer has a control unit (CPU) 11 composed of a computer or the like. The control unit 11
Key input data input from the key input unit 12 or a touch pen P input via a position detection circuit 15 from a tablet 14 provided on a display screen of a liquid crystal display unit 13 capable of performing color display. In response to the touch position data, a system program stored in the ROM 16 is started in advance, or the external storage medium 20 is activated.
A computer control program stored in advance in the RAM is read by the recording medium reading unit 19 and activated, and the RAM is read from the RAM.
17 is a work memory for controlling the operation of each part of the circuit.

The control unit 11 includes the key input unit 1
2, liquid crystal display unit 13, tablet 14, position detection circuit 1
5, ROM 16, RAM 17, recording medium reading unit 19
Are connected, and the liquid crystal display section 13 is connected to a display drive circuit 18.
Connected via

The key input section 12 is provided with a data input key 12a and a numeric keypad 12b composed of a character / symbol key group such as an alphabet key, an operator key, and a function key, and a graph display processing corresponding to an arbitrary function expression. The menu that is operated when displaying a menu screen of various operation modes such as a graph mode for performing calculation processing, a calculation mode for performing calculation processing corresponding to an arbitrary input expression, and a program mode for performing calculation processing corresponding to an arbitrary input program Key 12c, an "execute" key 12d operated when instructing confirmation of selected data or execution of a function, and "OK" operated when advancing individual processing to the next stage during execution of various processing. The key 12e is used to stop and hold the graph display processing based on the function formula input in the graph mode processing. "Stop" key 12f, etc. are provided to be.

The tablet 14 is provided on the display screen of the liquid crystal display unit 13 and generates a voltage signal corresponding to the position touched by the pen P. The coordinates corresponding to the display screen are detected by the position detection circuit 15 on the basis of the received voltage signal, and the control unit (CP
U) 11 determines the content of the operation.

The ROM 16 stores in advance system program data that governs the overall processing in the electronic circuit of the present computer, and also stores the program data shown in FIGS.
Control program data, which is subprogram data for controlling various operation modes such as a graph mode, is also stored in advance.

The RAM 17 has a display register 17a in which display data to be displayed on the liquid crystal display unit 13 is stored as bitmap pattern data, and a function expression data register 17b in which function expression data input in the graph mode processing is stored. A graph data register 17c in which graph data corresponding to the function expression stored in the function expression data register 17b is drawn and stored as bitmap pattern data, arbitrarily input by an operator, and stored in the function expression data register 17b A range register 17d that stores range data that specifies a drawing range of graph data corresponding to the set function expression, and data that is input and output by a control unit (CPU) 11 associated with control processing of various operation modes. Data registers such as work registers for storing It is.

Next, the operation of the computer having the above configuration will be described. FIG. 2 is a flowchart showing the overall processing of the computer. When the "menu" key 12c of the key input unit 12 is operated, a menu selection screen in which menu icons for selecting and setting operation modes such as a graph mode, a calculation mode, and a program mode are displayed on the liquid crystal display unit 13 ( Step S1 → S2).

In the display state of the menu selection screen, an arbitrary menu icon is selected by touching with a pen,
When the "execute" key 12d is operated, the selected operation mode is set, the control processing program corresponding to the set operation mode is started, and the initial display screen is displayed (steps S3 → S4, S5 → S6, S7). ).

When the graph mode is selected and set by the menu selection setting processing (steps S1 to S7), an initial display screen for inputting a graph function formula is displayed on the liquid crystal display unit 13, and the graph mode processing is performed. (Figure 3,
4 and 5) are activated (step S8 → S)
A).

When the calculation mode is selected and set by the menu selection setting process (steps S1 to S7), an initial display screen for inputting a calculation formula is displayed on the liquid crystal display unit 13, and the calculation mode process is performed. Is activated (steps S9 → S10).

When the program mode is selected and set by the menu selection setting process (steps S1 to S7), an initial display screen for inputting program data is displayed on the liquid crystal display unit 13, and the program mode process is performed. Is started (steps S11 → S12).

Further, when another operation mode is selected and set by the menu selection setting process (steps S1 to S7), the initial display screen is displayed on the liquid crystal display unit 13
Is displayed, the corresponding operation mode processing is started (step S11 → other processing).

FIG. 3 is a flow chart showing the graph mode processing in the computer. FIG. 4 is a flowchart showing a plotting process accompanying the graph mode process of the computer.

FIG. 5 is a flow chart showing the singular point processing accompanying the graph mode processing of the computer. FIG.
FIG. 4 is a diagram showing a graph drawing display state using a stop function accompanying the graph mode processing of the computer.

FIG. 7 is a diagram showing a graph drawing display state using a plotting function accompanying the graph mode processing of the computer. FIG. 8 is a view showing a graph drawing display state using a singular point function accompanying the graph mode processing of the computer.

FIG. 9 is a diagram showing a graph drawing display state using a pen input function accompanying the graph mode processing of the computer. As shown in FIG. 6A, in a state where the menu screen of the operation mode is displayed on the liquid crystal display unit 13 by operating the “menu” key 12c of the key input unit 12,
As shown in FIG. 6B, when the user selects “Graph” which is a menu icon on the menu screen by touching with a pen, the menu selection setting process (steps S1 to S7)
As a result, the graph mode processing is activated, and the initial display screen prompting the operator to input a graph function expression is displayed on the liquid crystal display unit 13.
(Step S8 → SA).

On the input screen of the graph function expression, the data input key 12a of the key input section 12 and the ten key
b is selectively operated to input a graph function expression to be drawn, for example, as "Y1 = Sin (Abs x)". The key-inputted function expression data is sequentially displayed on the liquid crystal display unit 13, and RA
It is stored in the function expression data register 17b in M17 (step A1 → A2).

Thus, an arbitrary graph function expression "Y1 = Sin
(Abs x) ”and operating the“ OK ”key 12e of the key input unit 12 as shown in FIG. 6C, the XY coordinates corresponding to the range data set in the range register 17d are changed. The learning menu “plot” M1 and “singular point” M2 are displayed on the liquid crystal display unit 13 along the lower end of the coordinate display screen (steps A3 → A4, A5).

Here, the learning menu "plot" M
1, "Singular point" M2 is not selected, and FIG.
As shown in the figure, when the user draws a graph by operating the "OK" key 12e of the key input unit 12, the input function expression "Y1 = Sin (Abs x)" stored in the function expression data register 17b in the RAM 17 is displayed. )) Is drawn and stored in the graph register 17c within the range of the range data stored in the range register 17d (steps A6 → A7).

Then, on the XY coordinates of the liquid crystal display unit 13,
It is determined whether or not there is a coordinate point display associated with plotting processing, singularity processing, or pen input drawing processing described later (step A8).

In this case, it is determined that no coordinate point display exists on the XY coordinates of the liquid crystal display unit 13, and the graph data register 17c is drawn and stored on the XY coordinates of the liquid crystal display unit 13. The input function expression “Y1 = Si
Graph data corresponding to “n (Abs x)” is sequentially drawn and displayed in black for each display dot, for example, starting from the X coordinate minimum value (steps A8 → A9).

Thus, an arbitrary input function expression “Y1 = Sin
(Abs x) ”is displayed on the liquid crystal display unit 13.
When the "stop" key 12f of the key input unit 12 is operated at an arbitrary display position in a state where the display is sequentially performed for each display dot on the XY coordinates of the graph, the drawing and display processing of the graph is stopped. A part of the displayed graph is held as it is displayed (step A10 → end).

That is, by displaying the graph data corresponding to the input function expression in an arbitrary part in response to the operation of the "stop" key 12f by the operator and stopping the operation, the operator can determine the overall locus of the graph data. It is possible to gain time to understand the trajectory by considering whether the trajectory is like this. After that, the “OK” key 1 of the key input unit 12
By re-operating 2e, the drawing and display processing of the graph data that has been stopped halfway in response to the operation of the "stop" key 12f is restarted, and the graph data is sequentially drawn and displayed over a wider coordinate range (step A6). → A7, A8
→ A9, A10 → A7).

Thus, the operator can draw and display a part of the graph data corresponding to the input function formula while gradually expanding the coordinate range, and can understand the trajectory of the graph. Eventually, the entire graph data can be drawn and displayed.

On the other hand, as shown in FIG. 6C, after inputting the graph function formula, the learning menu “Plot” M1 and “Singular point” M are displayed on the liquid crystal display unit 13 together with the XY coordinates.
In a state where 2 is displayed (steps A1 to A5),
As shown in FIG. 7A, when the “plot” M1 in the learning menu is designated by touching with a pen, the plotting process in FIG. 4 is started (step A11 → AB), and an arbitrary x coordinate value is input. The prompting message data "x =" is displayed along the upper end of the liquid crystal display unit 13 (step B1).

According to the x-coordinate value input message “x =” in the plotting process, as shown in FIG. 7B, the user operates the data input keys 12a and ten-keys 12b of the key input unit 12 to set an arbitrary x-coordinate. When "x = 3π / 2" is input and displayed and the "OK" key 12e is operated,
The input function expression "Y1 = Sin (Abs x)" stored in the function expression data register 17b in the RAM 14 is substituted with the input and displayed x coordinate value "x = 3π / 2", and is calculated. The corresponding y coordinate value “−1” is calculated and displayed, and the XY coordinate point q (3π / 2, −1) is plotted and displayed (steps B2, B3 → B4, B5, B).
6).

That is, in this plotting process, by inputting an arbitrary x coordinate value, the corresponding y coordinate value on the graph is calculated and plotted and displayed on the XY coordinates. From the plot display points on the XY coordinates, the trajectory of the graph data corresponding to the input function expression can be considered and imagined.

By the plotting process, for example, when the whole image of the graph data can be imagined, or when it cannot be imagined even if it is conceived, the key input unit 12 is set to “O”.
When the "K" key 12e is operated, the function expression data register 1
Graph data corresponding to the input function equation stored in 7b is drawn and stored in the graph data register 17c (steps A6 → A7).

In this case, it is determined that a coordinate point display associated with the plotting process exists on the XY coordinates of the liquid crystal display unit 13, and the graph data register 17c is stored on the XY coordinates of the liquid crystal display unit 13. Graph data corresponding to the input function formula “Y1 = Sin (Abs x)” drawn and stored is drawn and displayed in red for each display dot sequentially from, for example, the X coordinate minimum value (step A8 → A15). ).

Also in this case, it can be considered that the graph data can be stopped at an arbitrary drawing position in accordance with the operation of the "stop" key 12f, and finally the entire graph data can be drawn and displayed. Become.

On the other hand, as shown in FIG. 6C, after inputting the graph function formula, the learning menu “Plot” M1 and “Singular point” M are displayed on the liquid crystal display unit 13 together with the XY coordinates.
In a state where 2 is displayed (steps A1 to A5),
As shown in FIG. 8, the “singular point” M2 in the learning menu
Is designated by touching the pen, the singularity process in FIG. 5 is started (step A12 → AC), and the input function expression “Y1 = Sin” stored in the function expression data register 17b.
A singular point (maximum value, minimum value, x intercept, y intercept) corresponding to "(Abs x)" is calculated (step C1).

Then, the calculated input function expression “Y1 =
Each singular point corresponding to “Sin (Abs x)” is displayed on the liquid crystal display unit 13.
Is determined to be on the set XY coordinates, the coordinate points q1 to q9 corresponding to each singular point are displayed (steps C2 → C3).

When a coordinate point corresponding to the singular point is displayed, the coordinate value may be referenced and displayed. That is, in this singular point processing, each singular point on the graph is calculated and displayed as a coordinate point on the XY coordinates.
From the singular point display on the Y coordinate, it becomes possible to understand the trajectory of the graph data corresponding to the input function formula.

When the whole of the graph data can be understood by the above-mentioned singular point processing, or when it cannot be understood even if it is considered, "OK" of the key input unit 12 is performed.
When the key 12e is operated, the function expression data register 17b
Are drawn and stored in the graph data register 17c (steps A6 to A7).

In this case, it is determined that there is a coordinate point display accompanying the singularity processing on the XY coordinates of the liquid crystal display unit 13, and the graph data register 17c is displayed on the XY coordinates of the liquid crystal display unit 13. The graph data corresponding to the input function formula “Y1 = Sin (Abs x)” drawn and stored in the image is sequentially drawn and displayed in red for each display dot from the X coordinate minimum value, for example (step A8 → A15).

Also in this case, it can be considered that the graph data is stopped at an arbitrary drawing position in accordance with the operation of the "stop" key 12f, and finally the entire graph data can be drawn and displayed. Become.

On the other hand, as shown in FIG. 6C, after inputting the graph function expression, the learning menu “Plot” M1 and “Singular point” M are displayed on the liquid crystal display unit 13 together with the XY coordinates.
In a state where 2 is displayed (steps A1 to A5),
As shown in FIG. 9A, the input function expression “Y1 = Sin (Abs
x)), how the trajectory of the graph corresponding to
First, when the user thinks and inputs the graph data which seems to be correct by pen touch, the touch position data is sequentially detected from the tablet 14 via the position detection circuit 15, and the handwritten graph data is displayed on the XY coordinates of the liquid crystal display unit 13. (Step A13 → A1)
4).

Then, while the locus of the graph corresponding to the input function formula based on the operator's own idea is drawn and displayed by hand, as shown in FIG.
When the "OK" key 12e is operated, the graph data corresponding to the input function formula stored in the function formula data register 17b is drawn and stored in the graph data register 17c (steps A6 → A7).

In this case, it is determined that there is a coordinate point display associated with the singularity processing on the XY coordinates of the liquid crystal display unit 13, and the graph data register 17c is displayed on the XY coordinates of the liquid crystal display unit 13. The graph data corresponding to the input function formula “Y1 = Sin (Abs x)” drawn and stored in the image is sequentially drawn and displayed in red for each display dot from the X coordinate minimum value, for example (step A8 → A15).

Also in this case, it can be considered that the graph data is stopped at an arbitrary drawing position in accordance with the operation of the "stop" key 12f, so that the entire graph data can be finally drawn and displayed. Become.

Therefore, according to the computer having the above configuration, the graph function expression is input and the function expression data register 17 is input.
When the "OK" key 12e is operated, the graph data corresponding to the input function expression is drawn and stored in the graph data register 17c, and the graph data is stored in, for example, the minimum value of the X coordinate. Are sequentially displayed on the liquid crystal display unit 13 for each display dot in the direction of the maximum value.
When the "stop" key 12f is operated at an arbitrary graph display position, the graph display processing up to that point is stopped and held, and the "OK" key 1
When the operator operates 2e, the graph drawing / display processing is resumed, and the graph data is continuously displayed in a wider coordinate range. Therefore, the operator replaces a part of the graph data corresponding to the input function formula with the coordinate range. Is gradually expanded to draw and display, so that the trajectory of the graph can be considered and understood, and finally the entire graph data can be drawn and displayed.

Further, according to the computer having the above configuration, the graph function formula is inputted and stored in the function formula data register 17b, and the "plot" M1 in the learning menu displayed on the XY coordinates is touched with a pen. When the user selects and inputs an arbitrary x coordinate value, the corresponding y coordinate value on the graph is calculated and plotted and displayed on the XY coordinate.
The operator can imagine the trajectory of the graph data corresponding to the input function formula from the plot display points on the XY coordinates.

Further, according to the computer having the above configuration, the graph function formula is input and stored in the function formula data register 17b, and the "singular point" M2 in the learning menu displayed on the XY coordinates is touched with a pen. And select
Each singular point on the graph is calculated and displayed as a coordinate point on the XY coordinates, so that the operator can understand the trajectory of the graph data corresponding to the input function from the singular point display on the XY coordinates. Become.

Further, according to the computer having the above configuration,
By the handwriting input operation by touching the pen, the operator draws and displays the graph data corresponding to the input function formula considered to be correct on the XY coordinates.
By operating e, the correct graph data corresponding to the input function expression is drawn and displayed in a superimposed manner, so that the operator can learn what trajectory the graph data corresponding to the input function expression will have. .

The methods described in the above embodiment, that is, the entire processing of the computer shown in the flowchart of FIG. 2 and the graph mode processing shown in the flowcharts of FIGS. 3, 4, and 5 are executed by the computer. Memory card (RO)
M card, RAM card, etc.), magnetic disk (floppy disk, hard disk, etc.), optical disk (CD-
ROM, DVD, etc.), an external recording medium 2 such as a semiconductor memory
0 and can be distributed. Then, the computer reads the program recorded on the external recording medium 20 by the recording medium reading unit 19, and controls the operation by the read program, thereby realizing each function described in the above embodiment. A similar process can be executed by the method described above.

[0062]

As described above, according to the graph display device of the first aspect of the present invention, graph data corresponding to the function expression data input by the expression input means is created, and Since a part of the graph is displayed, the operator can consider what trajectory of the graph corresponding to the input expression will be.

According to the graph display device of the second aspect of the present invention, only the coordinate points corresponding to any designated points of the graph data corresponding to the function expression input by the expression input means are displayed. The operator can see the coordinate point corresponding to the arbitrary designated point and think what kind of trajectory the graph corresponding to the input expression has.

According to the graph display device of the third aspect of the present invention, only the coordinate points corresponding to the singular points of the graph data corresponding to the function expression input by the expression input means are displayed. Can look at the coordinate point corresponding to the singular point and think about the trajectory of the graph corresponding to the input expression.

According to the graph display device of the fourth aspect of the present invention, the graph data corresponding to the function expression input by the expression input means is sequentially displayed in a predetermined coordinate direction, and this graph data is displayed. Since the sequential display operation is stopped at an arbitrary point in time, the operator can see the graph corresponding to the input expression to an arbitrary range and think about the trajectory of the entire graph.

According to the graph display device of the present invention, the graph data corresponding to the function expression input by the expression input means is displayed on the display screen of the handwritten locus displayed by the handwriting data display means. Since the display is superimposed, the graph corresponding to the input function formula considered by the operator and the correct graph can be compared and displayed. Therefore,
It is possible for the operator to display a graph while considering what kind of trajectory the graph corresponding to the input function expression will be.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an electronic circuit of an electronic computer according to an embodiment of a graph display device of the present invention.

FIG. 2 is a flowchart showing the overall processing of the computer.

FIG. 3 is a flowchart showing a graph mode process in the computer.

FIG. 4 is a flowchart showing a plotting process accompanying a graph mode process of the computer.

FIG. 5 is a flowchart showing a singular point process accompanying the graph mode process of the computer.

FIG. 6 is a view showing a graph drawing display state using a stop function accompanying the graph mode processing of the computer.

FIG. 7 is a view showing a graph drawing display state using a plot function accompanying the graph mode processing of the computer.

FIG. 8 is a view showing a graph drawing display state using a singular point function accompanying the graph mode processing of the computer.

FIG. 9 is a view showing a graph drawing display state using a pen input function accompanying graph mode processing of the computer.

[Explanation of symbols]

 11: control unit (CPU), 12: key input unit, 12a: data input key, 12b: numeric keypad, 12c: "menu" key, 12d: "execute" key, 12e: "OK" key, 12f: "stop" Keys: 13: liquid crystal display unit, 14: tablet, 15: position detection circuit, 16: ROM, 17: RAM, 17a: display register, 17b: function formula data register, 17c: graph data register, 17d: range register, 18 ... display drive circuit 19 ... recording medium reading unit 20 ... external recording medium P ... touch pen M1, M2 ... learning menu.

Claims (7)

[Claims] An expression input means for inputting function expression data, a graph creation means for creating graph data of the function expression data input by the expression input means within a specified range, A graph display device for displaying a part of the graph data. 2. The graph partial display means is a graph partial display means for displaying only coordinate points corresponding to arbitrary designated points of graph data corresponding to a function expression input by the expression input means. The graph display device according to claim 1. 3. The graph partial display means is a graph partial display means for displaying only coordinate points corresponding to singular points of graph data corresponding to the function expression input by the expression input means. The graph display device according to claim 1. 4. A graph display means for sequentially displaying graph data corresponding to a function expression input by the expression input means in a preset coordinate direction, and graph data by the graph display means. 2. The graph display device according to claim 1, wherein the graph display device comprises display stop means for stopping the sequential display operation at an arbitrary time. 5. An expression input means for inputting a function expression, a handwritten data display means for drawing and displaying a trajectory accompanying a handwriting operation, and a graph data corresponding to the function expression inputted by the expression input means, A graph display device comprising: a graph display unit for displaying a handwritten locus displayed by the handwritten data display unit on a display screen in a superimposed manner. 6. An expression input step of inputting function expression data, a graph generation step of generating graph data of the function expression data input in the expression input step within a specified range, and a graph generation step And displaying a part of the graph data. 7. An expression inputting means for inputting function expression data to a computer, a graph generating means for generating graph data of the function expression data input by the expression inputting means within a specified range, A medium for recording a graph display program for functioning as a graph partial display means for displaying a part of the generated graph data.