JPH0638250B2 - Small electronic calculator with graph display function - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a small electronic calculator having a graph display function.

[Prior art and its problems]

2. Description of the Related Art Conventionally, there is a small electronic computer such as a personal computer or a pocket computer that can display a graph by creating a BASIC program and inputting data.

However, in the above-mentioned conventional compact electronic calculator having a graph display function, it is necessary to build a program dedicated to the graph. Therefore, those who are not familiar with the program cannot easily create the graph, and those who are used to it Even then, the input operation was very troublesome.

[Object of the Invention]

The present invention has been made in view of the above points, and an object thereof is to provide a small electronic calculator having a graph display function capable of displaying a range of solutions of inequalities or simultaneous inequalities in a graph by simple key operation. And

[Main points of the invention]

The present invention comprises input means for inputting an inequality or simultaneous inequalities using an inequality key, and calculates graph data based on the inequality or simultaneous inequalities input by this input means and the range data stored in the range data storage means. Then, based on the calculated graph data, the dot display body on one side of the graph is displayed differently from the dot display body on the other side of the graph with the graph as a boundary.

Example of Invention

An embodiment of the present invention will be described below with reference to the drawings. First
In the figure, numeral 11 is a key input section, which is a numeral key 12, a function key 13, a function key 14, and a Graph key 1.
5, ";" key 16, Ra for inputting range data
With the nge key 17, "=", "≠",
Equivalent / inequality sign keys 18 such as “>”, “<”, “≧”, and “≦” are provided. Then, the input data from the key input unit 11 is sent to the control unit 20. This control unit 20
Stores various control programs, supplies a sampling signal to the key input section 11, and calculates the control section 2
1, control commands are given to the formula buffer 22 and the display buffer 23. In addition, the control unit 20 supplies input data to the arithmetic unit 21 and the mathematical formula buffer 22 in response to a key operation of the key input unit 11, and also a storage unit 2 including a RAM or the like.
Address data and a read / write command are given to 4.
The arithmetic unit 21 is connected to the formula buffer 22 and the storage unit 24. The mathematical expression buffer 22 also serves as an input buffer and temporarily stores key input data. Further, the data output from the arithmetic unit 21 is sent to the display buffer 23. The display buffer 23 is composed of a text display buffer 23a and a graph display buffer 23b, and is addressed by the data sent from the storage unit 24 via the address decoder 25, and the data from the operation unit 21 is written to the designated address. Get caught. Then, the display buffer 23 outputs the data written in the text display buffer 23a and the graph display buffer 23b to the display unit 26 for display. The display unit 26 has a dot matrix configuration in which the number of segments (dots) in the X-axis direction is M, for example, 96, and the number of segments (dots) in the Y-direction is N, for example, 64.
In the X-axis direction, the leftmost end is set to the minimum value X _min , the rightmost end is set to the maximum value X _max , the bottom end is set to the minimum value Y _min , and the top end is set to the maximum value Y _max , and the input data (X,
For (Y), the coordinate position is displayed by (x, y) data.

Then, in the storage unit 24, the data memory 31, the previous plot 1 memory 32, the previous plot 2 memory 33,
This time plot 1 memory 34, this time plot 2 memory 3
5, this plot 3 memory 36, range data X _min , X _max , Y _min , Y _max , X-axis scale data (X-axis scale width) Xscale, Y-axis scale data (Y-axis scale width) Y _scale, etc. A range memory 37 for storing data, a memory 38 for storing X-axis data, a Y ₁ memory 39 for storing Y-axis data, a Y ₂ memory 40, an x memory 41, an n memory 42, and a calculation data memory 43 are provided. .

Next, the operation of the above embodiment will be described. First, the operation for displaying the inequality graph will be described with reference to the flowchart of FIG. First, as shown in step A1 of FIG. 2, by the numerical key 12 and the range key 17,
Set the X-axis and Y-axis range and scale. That is, when the Range key 17 is operated, the range setting items are displayed on the display unit 26, so that X _min , X _max , ...
Data is input in the order of Y _max and Y _scale . The range data is sent from the control unit 20 to the storage unit 24 and written in the range memory 37. Then step A
2, the contents of the x memory 41 indicating the number of dots (X-axis direction) from the leftmost end of the display unit 26 are initialized (“1” is set). After that, as shown in step A3, Graph
The key 15 is operated to input the inequality function expression “Y>(<, ≧, ≦) F (x)” such as “Y> 2X ² +3”. When the inequality function expression is input as described above, the calculation unit 21 follows the control of the control unit 20 and indicates at step A4. Is calculated, and the value of X at the x-th dot is calculated at the leftmost end of the X-axis. In the above equation, M is the total number of dots in the X-axis direction and is stored in the storage unit 24 in advance. Then, the value of X obtained by the above calculation is input to the X memory 38 as shown in step A5. Then step A6
Based on the value in the X memory 38, “Y = F
(X) ”is calculated to obtain the value of Y, and the value is stored in the Y ₁ memory 39 in step A7. Then, based on the value of the Y ₁ memory 39 as shown in step A8, Is calculated to obtain the dot position y in the Y-axis direction.
In the above equation, N is the total number of dots in the Y-axis direction, and the storage unit 24
Stored in advance. Then, the dot position data (x, y) obtained as described above is calculated in step A9.
At this time, it is stored in the plot 1 memory 34 at the same time, and at the step A10, the graph display buffer 23b is stored.
And display it on the display unit 26. Next, step A1
As shown in 1, the n memory 42 that stores the variable n is initialized, that is, "1" is written. After that, the process proceeds to step A12, where the function input in step A3 is “Y <F
(X) ”or“ Y ≦ F (x) ”or“ Y> F
(X) ”or“ Y ≧ F (x) ”.

In the above step A12, "Y <F (x) or" Y
If ≦ F (x) ”, the partial display processing of the solution is performed in step A13 and the subsequent steps. That is, step A1
In step 3, it is determined whether the dot position y in the Y direction obtained in step A8 is “y ≧ 0” and “y ≦ 0”.
Only when, the following partial display process of the solution is performed.
Subtracting a variable n from the dot position y in the Y-axis direction as shown in step A14, to the subtraction result as y _n. Then, in step A15, the dot position data (x, y
_n ) is stored in the plot 2 memory 35 this time, and then "Y <F (x)" is satisfied in step A16.
(X) to determine whether a "," Y ≦ F (x) "above this plot 2 memory 35 are stored (x, y _n) all graphical display buffer as indicated to step A18 in the case of It is stored in 23b and displayed on the display unit 26. If "Y <F (x)", step A17
The process advances, or when the even x and y _n are both together only if an odd number, and stores are held in this plot 2 memory 35 proceeds to step A18 to (x, y _n) in the graph display buffer 23b, It is displayed on the display unit 26. afterwards,
In step A19, it is determined whether or not y _n has become "0", and if not "0", in step A20 the n memory 4
The content of 2 is incremented by "+1" and the process returns to step A14. In the same manner, the processes of steps A14 to A18 are sequentially repeated until y _n becomes "0", and the process of steps A13 to A17 displays "Y < F (x) ”(or“ Y> F
(X) ”: described later), every other dot is in a lighting state, and a check pattern is obtained as a whole. In addition, “Y ≦
When F (x) ”(or“ Y ≧ F (x) ”: described later), all the dots are in the lighting state.

On the other hand, if the result of the determination at step A12 is NO, that is, if "Y> F (x)" or "Y≥F (x)", then the display process of the solution portion is performed after step A21. That is, in step A21, it is determined whether or not the value of y is "y≤N", and only when "y≤N", the display processing described below is performed. First, in step A22, n is added to the value of y to obtain y _n . Then, in step A23, the dot position data (x, y
_n ) is stored in the plot 2 memory 35 this time, and then whether Y> F (x) ”or“ Y ≧ F ”in step A24.
Determining whether a (x) "," Y ≧ F (x) "the current plot 2 is stored in the memory 35 (x, y _n) all graphical representation as shown to step A26 in the case of The data is stored in the buffer 23b and displayed on the display unit 26. If "Y> F (x)", step A25
Only when both x and y _n are even or both are odd, the process proceeds to step A26, where (x, y _n ) currently held in the plot 2 memory 35 is stored in the graph display buffer 23b, It is displayed on the display unit 26. afterwards,
In step A27, it is determined whether or not y _n has become "N", and if not "N", in step A28 the n memory 4
The contents of 2 are incremented by "+1" and the process returns to step A22. In the same manner, the processes of steps A22 to A26 are sequentially repeated until y _n becomes “N”.

Then, if it is determined in step A27 that the value of y _n has reached “N”, the process proceeds to step A29,
It is determined whether or not the dot position x in the X-axis direction is "1", and only when "x ≠ 1", the following steps A30, A
31 is performed. That is, in step A30,
Previously stored data in plot 1 memory 32 (x ₀ , y ₀ )
The dot (p, q) connecting the dots of the data (x, y) held in the current plot 1 memory 34 (described later) is obtained. Then, as shown in step A31, the dot (p, q) is stored in the graph display buffer 23b and displayed on the display unit 26 in step A32. That is, regarding the dot (p, q), in the dots (Y-axis direction) existing between the dots that are turned on corresponding to the contents of the current plot 1 memory 34 and the previous plot 1 memory 32, the dot in the middle is obtained, The dots from the lighted dot to the intermediate dot corresponding to the contents of the plot 1 memory 32 are made to light up with the dot in the previous plot 1 memory 32 at the same position in the X-axis direction, and from the intermediate dot to the current plot 1 memory 34. The dots up to this point are lit up with the dot in the current plot 1 memory 34 at the same position in the X-axis direction. When the number of dots existing between the current plot 1 memory 34 and the previous plot 1 memory 32 is odd,
Whether the position of the dot located in the middle in the X-axis direction is the same as the previous plot 1 memory 32 or the current plot 1 memory 34 is determined in advance. The processing of steps A29 to A31 is the display processing of the solution part,
That is, it may be performed between step A10 and step A11.

Then, in step A33 following the graph display in step A32, it is determined whether or not "x = M", and "x = M"
If "M", the display process is terminated, but if "x ≠ M", the process proceeds to step A34, where x and y are x ₀ and y, respectively.
_It is set to ₀ and stored in the previous plot 1 memory 32 in step A35. After that, as shown in step A36, the content of the x memory 41 is incremented by "+1", and the process returns to step A4. The above process creates the inequality graph and
It is displayed on the display unit 26 as shown in (a). FIG. 3 (a) shows “Y> AX ² + BX + C” or “Y ≧ AX ² + BX +”.
FIG. 6 shows a C ”inequality graph. Also, FIG.
(b) and (e) are enlarged views of the display state of area A in FIG. 3 (a). That is, FIG. 3 (a) shows “Y> F
In the case of (x) ”or“ Y <F (x) ”, every other dot is in a lighting state, and a check pattern is obtained as a whole. Further, FIG. 3 (b) shows that “Y ≦ F (x)” or “Y =
In the case of "F (x)", all the dots are in a lighting state.

Next, the simultaneous inequality graph display processing will be described with reference to the flowchart in FIG. First, in steps B1 and B2 in FIG. 4, the X-axis and Y-axis ranges and scales are set and "1" is set in the x-memory 41 as in steps A1 and A2 in the above inequality graph display. Next, as shown in step B3, the data of the simultaneous inequalities is input in the format of the third inequality and the second inequality, and in steps B4 to B10, the same processing as in steps A4 to A10 described above is performed.
y ₁ ), and thereafter, as shown in step B12, the dot (p ₁ , q ₁ ) connecting the dots in the previous plot 1 and the present plot 1 is determined. Then, in step B13, the dot (p ₁ , q ₁ ) is written in the graph display buffer 23b and displayed on the display unit 26.

Next, in steps B14 to B21, (x, y of the second expression
₂ ) is obtained and stored in the plot 2 memory 35 this time, and a dot (p ₂ , which connects the dot formed by the data stored in the plot 2 memory 33 last time and the dot formed by the data stored in the plot 2 memory 35 this time) q ₂ ) is calculated. Then, the dot (p ₂ , q ₂ ) is stored in the graph display buffer 23b and displayed on the display unit 26.

Then, in step B22, after initializing the variable n, the relationship between the first inequality and the second inequality is determined in steps B23, B37, and B46. And step B
23, it is determined that the first inequality is Y ₁ <F ₁ (x) or Y ₁ ≦ F ₁ (x) and the second inequality is Y ₂ <F ₂ (x) or Y ₂ ≦ F ₂ (x) If it does, steps B24 to B30
Is displayed. That is, it is determined whether the step B24 _"y 1> _{y 2", "y} 1> _{y 2"}
Only in this case, the display processing of steps B25 to B30 is performed. Furthermore, in step B25, if it is determined that “y ₁ ≧ 0” or “y ₂ ≦ N”, step B26.
~ The process of B30 is executed. Processing in step B26~B29 is the same as that of the "Y> F (x)" graphical representation of the inequality, the process of step B26~B29 in step B30 until _{y n} is determined to have become equal to _{y 1} Is repeated. However, in step B26 corresponding to step A22, “y ₂ + n” is set to “y _n ”. Thereafter, the process returns to step B4 through steps B32 to B36, and the process is continued until it is determined in step B33 that "x = M".

Also, in step B37, the first inequality is Y ₁ > F
₁ (x) or Y ₁ ≧ F ₁ (x) If it is determined that the second inequality is Y ₂ <F ₂ (x) or Y ₂ ≦ F ₂ (x), steps B38 to B44.
Is displayed. Then, in step B38, "y ₁
<Y ₂ ”, in step B39“ y ₁ ≦ N ”or“ y
_When it is determined that “ ₂ ≧ 0”, the processes of steps B40 to B44 are performed. The processing of steps B40 to B44 is similar to the case of "Y> F (x)" in the above inequality graph display (however, y _n ← y ₁ + n is set, and as shown in step B44, "y _n = y ₂ It will continue until.
The process returns to step B32 and the following process is executed.

On the other hand, in step B46, the first inequality is Y ₁ <F ₁ (x) or Y ₁ ≦ F ₁ (x) The second inequality is Y ₂ <F ₂ (x) or Y ₂ ≦ F ₂ (x) If it is determined that the value is “y ₁ ≦ y ₂ ”, it is determined whether the condition is “y ₁ ≦ y ₂ ”. Step B
When it is determined in 47 that "1≤y ₂ ", the same processing as the inequality graph display of "Y ₁ <F ₁ (x)" is performed in steps B48 to B53.

If it is determined in step B47 that “y ₁ ≦ y ₂ ” does not hold, that is, if “y ₁ > y ₂ ”, in steps B55 to B61, “Y ₂ <F _2.
2 (x) ”inequalities are drawn.

If the determination result in step B46 is NO, the first inequality is Y ₁ > F ₁ (x) or Y ₁ ≧ F ₁ (x) The second inequality is Y ₂ > F ₂ (x) or Assuming that Y ₂ ≧ F ₂ (x), the processes of steps B63 to B77 are performed. That is, in step B63, “y ₁ ≧
It is determined whether or not “y ₂ ”, and if “y ₁ ≧ y ₂ ”, “Y ₁ > F ₁ (x)” in steps B64 to B69.
The same processing is performed. If it is determined in step B63 that “y ₁ ≧ y ₂ ” does not hold, that is, if “y ₁ <y ₂ ”, the same as “Y ₂ <F ₂ (x)” in steps B71 to B77. Is processed. Through the above processing, a graph display of simultaneous inequalities as shown in FIG. 5 is performed. Note that FIG. 5 shows simultaneous inequalities “Y <A ₁ X+B ₁ ”, “Y> A ₂ X ² + B ₂ X + C”.
The graph display example is shown for the case.

In the graph display process of the simultaneous inequalities, “Y
For “> F (x)”, the graph may be lit every dot, and for “Y ≧ F (x)”, it may be a normal display, and in the range, it may be lit for every dot. If "Y> F (x)", a normal graph is displayed. If "Y≥F (x)", a thick line graph of 2 dots is used, and each dot is lit in the range. May be. By performing the lighting process as described above,
Even when the simultaneous equations including “Y> F (x)” and “Y ≧ F (x)” are plotted in the graph, the distinction can be made more clearly.

Next, the negative-type graph display process will be described with reference to the flowchart of FIG. First, as shown in step C1, the X-axis and Y-axis ranges and scales are set, and then in step C2, the contents of the x memory 41 are initialized. Then, after inputting the negative function expression "Y ≠ F (x)" in step C3, all the dot numbers of the display unit 26 are brought into the display state as shown in step C4. Then, as shown in steps C5 to C10, (x, y) is obtained by the same method as that described above. Then, as shown in step C11, (x, y) is masked in the graph display buffer 23b. Then step C
In 12, it is determined whether or not the content of the x memory 41 is "1", and if it is "1", the process proceeds to step C13 to obtain the point (p, q) connecting the previous plot 1 and the current plot 1 . After that, as shown in step C14, (p, q) is masked in the graph display buffer 23b,
In step C15, the contents of the graph display buffer 23b are displayed on the display unit 26. Then, in step C16, it is determined whether or not “x = M”, and “x = M”.
Otherwise, x, y as shown in steps C17 and C18
Is set to x ₀ , y _0, and (x ₀ , y ₀ ) is stored in the previous plot 1 memory 32. Then, after writing the value of "x ₀ +1" to the x memory 41, the process returns to step C5 and the same process is repeated. Then, in step C16, "x
= M ”, the processing ends. As described above, as shown in FIG. 7, the graph of "Y = F (x)" is displayed in a white state.

〔The invention's effect〕

As described above in detail, according to the present invention, the range of the solution of the inequalities or simultaneous inequalities can be displayed as a graph by a simple key operation. Therefore, the X and Y regions (the range of the solution) of the inequalities can be displayed. It can be easily confirmed visually. Further, by providing the graph display function as described above, the function as a small electronic calculator can be expanded.

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a block diagram showing a circuit configuration, FIG. 2 is a flowchart showing an inequality graph display processing operation, and FIG. 3 (a) is an inequality graph display example. Fig. 3 (b) and (c) are enlarged views of a part of Fig. 3 (a), Fig. 4 is a flowchart showing the simultaneous inequality graph display processing operation, and Fig. 5 is FIG. 6 is a diagram showing an example of simultaneous inequality graph display, FIG. 6 is a flowchart showing a negative-type graph display processing operation, and FIG. 7 is a diagram showing a negative-type graph display example. 11 ... Key input section, 12 ... Numeric key, 13 ... Function key, 14 ... Function key, 15 ... Graph key, 17 ... Range key, 18 ... Equal sign / Inequal sign key,
20 ... Control unit, 21 ... Arithmetic unit, 22 ... Formula buffer, 23 ... Display buffer, 23a ... Text display buffer, 23b ... Graph display buffer, 24 ... Storage unit, 25 ... Address decoder, 26 ... Display unit, 31
...... Data memory, 37 ...... Range memory, 41 ...... Calculation data memory.

Claims (1)

[Claims] 1. A dot matrix display means, an inequality key, an input means for inputting an inequality or simultaneous inequality using this inequality key, and a range for storing range data of the inequality or simultaneous inequality input by this input means. Data storage means, graph data calculation means for calculating graph data based on the inequalities or simultaneous inequalities input by the input means and the range data stored in the range data storage means, and the graph data calculation means. And a graph display control means for displaying the dot display on one side of the graph differently from the dot display on the other side of the graph based on the graph data. A small electronic calculator with functions.