JPH1125074A - Expression editing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To add parentheses desired by a user to a described mathematical expression term by preparing three kinds of a composing processing for adding parentheses, and switching a mode by the user. SOLUTION: An editing means A constituted of a composition controlling part 503, relative coordinate calculating part 506, absolute coordinate calculating part 505, and syntax analyzing part 504 have three modes, that is, a parenthesis priority mode, reference position priority mode, and size priority mode at the time of adding parentheses to a fractional expression. The layout of the character string of a character string storing part 502 is decided by referring to the format information of a format information storing part 508. In the parenthesis priority, the central position of the parentheses is made coincident with the position of a fractional line, and parentheses matched with the height of the larger term among the denominator term and numerator term of the fractional expression are generated. In the reference position priority mode, the reference position of the parentheses is made coincident with the position of the fractional line, and the upper half part of the parentheses is matched with the height of the numerator term, and the lower half part of the parentheses is matched with the height of the denominator term. In the size mode, parentheses matched with the height of the whole fraction are generated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a formula editing apparatus capable of easily editing mathematical formulas and chemical formulas (these formulas are referred to as formulas) in an information processing device such as a personal computer.

[0002]

2. Description of the Related Art In editing a formula, terms whose height from the center in the vertical direction (hereinafter, referred to as height) and size from the center below (hereinafter, referred to as depth) are arranged are different. We have to go. For example,

[0003]

(Equation 1)

[0004] In the case of a fractional expression such as
+ Z + 1 and the denominator term is

[0005]

(Equation 2)

Thus, the height of the numerator does not match the height of the denominator. In general, when describing such a fractional expression, it is a rule that the center of the letter "y" and the letter "=" is aligned with the position of the fraction line. In addition, in mathematical formulas and chemical formulas, parentheses are often arranged before and after terms of various heights. For example, the following mathematical expression is used.

[0007]

(Equation 3)

In this case, the size of the parentheses is adjusted according to the size of the item in the parentheses, and the rule is such that the centers of the characters "y" and "=" are aligned with the centers of the parentheses. . When parentheses are added to continued fractions according to the above two rules, the conventional formula editing apparatus can only arrange parentheses whose size is offset to the height (or depth) as follows.

[0009]

(Equation 4)

[0010]

As described above, the conventional formula editing apparatus has a problem in that it depends on the ability to describe formulas including parentheses.

Accordingly, an object of the present invention is to provide a formula editing apparatus capable of expressing a formula including parentheses as desired by a user.

[0012]

The formula editing apparatus of the present invention comprises:
A display unit for displaying an editing result, a character input unit for inputting character strings constituting an expression and format information relating to the layout of the character strings, a character string storage unit for storing the input character strings, and input format information A format information storage unit for storing the character string layout of the character string storage unit by referring to the format information of the format information storage unit, and displaying the layout on the display unit. When adding parentheses, a parenthesis priority mode that matches the center position of the parentheses with the position of the fraction line and generates parentheses that match the height of the larger of the denominator and numerator in the fractional expression, and the parenthesis reference position A reference position priority mode in which the upper half of the parentheses matches the height of the numerator term, and the lower half of the brackets matches the height of the denominator term,
A size priority mode for generating parentheses that match the height of the entire fraction regardless of the position of the fraction line.

With this configuration, it is possible to realize a formula editing apparatus capable of expressing a formula including parentheses as desired by the user.

[0014]

According to a first aspect of the present invention, there is provided a formula editing apparatus for displaying a result of editing, a character input unit for inputting a character string constituting an expression and format information relating to the layout of the character string. A character string storage unit for storing a character string, a format information storage unit for storing input format information, and a layout of a character string in the character string storage unit determined and displayed with reference to the format information in the format information storage unit. Editing means for displaying the part in parentheses, when the parentheses are attached to the fractional expression, the center position of the parentheses is matched with the position of the fraction line, and the height of the larger one of the denominator term and the numerator term of the fractional expression is A parenthesis priority mode that generates parentheses that match the standard, and a standard that matches the reference position of the parentheses with the position of the fraction line, and adjusts the upper half of the parentheses to the height of the numerator and the lower half of the parentheses to the height of the denominator. Position priority mode,
A size priority mode for generating parentheses that match the height of the entire fraction regardless of the position of the fraction line.

With this configuration, by allowing the user to select one of these modes, it is possible to arrange well-balanced parentheses for terms having different heights and depths.

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a formula editing apparatus according to an embodiment of the present invention. In FIG.
101 is a CPU, 102 is a RAM for storing programs, character strings, and format information for controlling the CPU 101
(Random access memory); 103, a keyboard; 104, a CRT; 105, an auxiliary storage device for storing created documents and the like; 106, a pointing device (for example, a mouse) for indicating a window displayed on the CRT; It is a printer.

Next, as a premise of the present invention, a basic formula editing method will be described. FIG. 2 is a mathematical expression parsing diagram in one embodiment of the present invention. As shown in FIG.
A mathematical expression is formed by a sequence of “terms”. What is a term?
As shown in (b), it is composed of any of "character", "fraction", "matrix", "with parenthesis" and the like. Among them, “character” is the minimum unit of a mathematical formula component and is represented by a circle in the figure. “Fraction”, “matrix”, and the like are represented by □ since constituent elements are further expanded. Important elements in the present invention are “fraction” in FIG. 2C and “with brackets” in FIG. 2D.

As shown in FIG. 2C, the fraction is composed of "numerator", "denominator" and "fraction line". The fraction line is the smallest element of the mathematical composition. The numerator and denominator are "formulas"
Therefore, a fraction may appear again in the numerator and denominator. As shown in FIG. 2D, parentheses appear in parentheses before the “expression” and also after the term.

The mathematical expression explained in FIG.
3) will be described with reference to FIG. Here, each character has reference point data for arranging the characters. The size above the reference point is called “height”, and the size below is called “depth”. In mathematical expression formatting, the reference point y
The characters are arranged rightward while making the coordinates coincide (FIG. 3A). The same applies when a term other than “character” appears.

For example, when characters and fractions are mixed (FIG. 3
(B)) If the reference position of the fractional item is generated when the fractional item is created, the fractional item can be arranged in the same manner as a normal character arrangement. The reference position of the fraction term is generated as shown in FIG. Here, the fraction term has "numerator", "denominator", and "fraction line" as its elements. At the stage of forming the fraction, the size and reference position of each element are determined, and the typesetting of the fraction focuses solely on the arrangement of the numerator, denominator and fraction lines. The typesetting rules for fractions are as follows:

First, in the horizontal direction, the centers of the numerator and the denominator are aligned and the protruding amount of the fraction line is considered from the larger numerator or the denominator. In the vertical arrangement, the heights of the numerator, the fraction line, the denominator and the distance between each are taken into consideration. Then, the relative position between the numerator, denominator and fraction is determined, and the size (width / height / depth) of the whole fraction term is determined. Further, the reference coordinates of the fraction are set at the left end of the fraction line and the center position of the line width, and the coordinates of the numerator, denominator and fraction line are recorded as relative coordinates from that position.

In the case of "with parentheses", the height of the character "bracket" is calculated from the height of the "expression", and the center position of "bracket" is aligned with the center position of "mathematical expression" (FIG. 3 (d)). )). FIG.
(A) shows an example of a mathematical expression described here. In this example,

[0023]

(Equation 5)

Are described, and parentheses are attached according to the size. The characters "x, +, y" and "fraction" are described in the formula.

"Fraction" is a continued fraction, and the fraction is described again in the denominator term. When formatting mathematical formulas, it is necessary to know the size (width, height, depth) of each term. For this reason,
In the formula of FIG. 4A, the composition is performed from the deepest fraction of the continued fraction. That is, as shown in FIG.

[0026]

(Equation 6)

Then, typesetting is performed. In this fraction, the numerator term and the denominator term are all composed of characters only.
Therefore, in the numerator term and the denominator term, the typesetting is performed as shown in FIG. 3B, and in the numerator term, the characters "x, +, y" are centered in the y-direction, and the typesetting is performed while being sent rightward. Further, since all the constituent elements (numerator term, denominator term, fraction line) are characters or lines in this fraction, the height, depth and width of this fraction can be calculated from such information.

For example, when the origin is at the left end of the fraction line, the coordinates (relative coordinates) of each component can be determined. Next, the setting of the fraction using the fraction of FIG. 4B as the denominator term is shown in FIG.
This will be described with reference to FIG. In FIG. 4C, the numerator terms are all characters, and the denominator terms are fractions formatted in FIG. 4B. Therefore, since the size of each element is already known, the size of the fraction and the coordinates of each element can be calculated by the usual fraction typesetting rule.

Similarly, FIG. 4 (d) shows a typesetting of a fraction having the fraction of FIG. 4 (c) as a denominator term. Up to FIG. 4D, the size and relative coordinates of each component of the continued fraction can be calculated. FIG. 4E shows the typesetting of (Equation 5). The magnitude of the continued fraction in this equation is determined in FIG. From this, the first elements "character: x" are arranged while being sent at the width of each element with the center of the left end as the origin. In the vertical direction, the origin of each element (the center for a character element) is matched. By performing this typesetting, the width, height, and depth of the mathematical expression can be obtained. Finally, the composition with "brackets" is performed (FIG. 4 (f)).

A mathematical term which is one of the components of "with brackets" is obtained in FIG. 4 (e). The width of the parentheses is the character size. Therefore, what has to be calculated here is the vertical multiple of the parentheses. To find the vertical multiple, compare the height and depth of the formula term, select the larger value, and calculate the multiple that is closer to that value.
After that, parentheses, formulas, and parentheses are arranged in this order, and the relative coordinates of each element and the width, height, and depth of the entire brackets are obtained. Finally, when the absolute coordinates of the reference position in parentheses are determined, the absolute coordinates of each element are determined based on the values.

Now, a description will be given of how to improve the composition with brackets performed by such a method and arrange the parentheses in the three modes described above. FIG. 5 is a functional block diagram of the formula editing apparatus according to the embodiment of the present invention. FIG.
In FIG. 1, reference numeral 501 denotes a character input unit for inputting a character string constituting an expression, format information on the layout of the character string, and the like, and corresponds to the keyboard 103 and the mouse 106 in FIG.

Reference numeral 502 denotes a character string storage unit that stores an input character string, and reference numeral 508 denotes a format information storage unit that stores input format information, and corresponds to the RAM 102 or the auxiliary storage device 105. A is an editing unit having a typesetting control unit 503, a relative coordinate calculation unit 506, an absolute coordinate calculation unit 505, and a syntax analysis unit 504. The editing unit A uses a parenthesis priority mode, a reference position, It has three modes, a priority mode and a size priority mode.
The layout is determined with reference to the format information 8 and is realized by the CPU 101 in FIG. 507
Is a display unit for displaying the editing result.
04 or the printer 107.

Here, when a character is input by the user, the character information is stored in the character string storage unit 502 through the character input unit 501. The character string stored in the character string storage unit 502 is taken out when a typesetting request is issued from the typesetting control unit 503 in the editing unit A, and the syntax analysis unit 50.
Passed to 4.

The syntax analysis unit 504 has a tree-structured data structure (FIG. 6) so that the parent-child relationship of each term of the formula can be easily grasped.
Expand to FIG. 6 abstractly shows the data structure of the mathematical expression described in FIG. In the mathematical expression developed by the syntax analysis unit 504 into a tree structure format, the relative coordinate calculation unit 506 calculates the size of each element and the relative coordinates from its parent.
At this time, format information such as the thickness of the fraction line is referred to from the format information storage unit 508.

In the present invention, an item of the alignment rule of “with parentheses” is prepared in the format information, and the relative coordinate calculation unit 506 is provided.
Is referred to when calculating a multiple / relative coordinate of a parenthesis character, and generates a parenthesis desired by the user even in a mathematical expression having only a deep depth such as a continued fraction. When the relative coordinates are obtained for all the tree-structured data elements, the typesetting control unit 503 calls the absolute coordinate calculation unit 505. The relative coordinate calculation unit 506 calculates the absolute coordinates of each element from the coordinates of the entire mathematical expression and the value of the relative coordinates of each element. When the absolute coordinates of all elements are obtained, the typesetting control unit 50
3 calls the display unit 507, and displays a character,
Draw lines and so on.

Next, as a specific example, FIG. 7 shows a state in which the formula of FIG. 4A is typeset in parentheses priority mode, size priority mode, and reference position priority mode. Reference numeral 701 corresponds to the state shown in FIG. The typesetting steps up to 701 have been described above and will not be described. Thereafter, the user refers to the format information set by the user, and if the mode is the parentheses priority mode 702
Typesetting, if the size priority mode, 703 typesetting,
If the mode is the reference position priority mode, 704 typesetting is performed. In the parentheses priority mode, the multiple of the parentheses suitable for the size of the formula term is calculated based on the value of the formula term having a large height or depth. In 702, since “depth> height”,
The multiple is calculated so that the depth of the parentheses is "40".
That is, the multiple in the height direction of the parentheses is four times, and the multiple in the depth direction is also four times.

Next, the relative coordinates of "with parentheses" are obtained. Since the parenthesis character and the reference position of the formula term are the origin of each term,
The value of the relative coordinate y direction is always fixed at “0”. The x direction is calculated based on the pitch of the bracket characters and the width of the formula term.

Finally, the height, depth, and width of the whole “with parentheses” are calculated. In the size priority mode, the size of the parentheses is adjusted to the size of the mathematical expression in the y direction. The center position of the parentheses coincides with the center position in the y-direction size of the formula term, regardless of the reference position of the formula term. In 703, the multiple of the parenthesis character is calculated by the value of “height + depth” in the mathematical expression. Since the parenthesis character is a character having a balanced height and depth from the reference position, the multiple in the height direction and the multiple in the depth direction are half the calculated multiple.

Next, the relative coordinates of the opening parenthesis character, the formula term, and the closing parenthesis character are calculated. Similar to 702, the relative coordinates in the x direction are calculated by sending the parenthesized characters at the pitch and the width of the formula term.
The y coordinate of the parenthesis character is (size in the parenthesis character height direction) −
(The height of the formula term). For this reason, the reference position of the parenthesis character does not match the reference position of the formula term, but a parenthesis matching the size of the formula term is attached. In the reference position priority mode, a multiple in the height direction and a multiple in the depth direction of the parentheses are set as different values, and the balance of the parentheses is lost, but the reference position and the size are matched. In 702, the multiple of the parenthesis is obtained by each of “height” and “depth” in the mathematical expression.

In this mode, the size of the parentheses matches the vertical size of the mathematical expression, and also matches the reference position.
Therefore, the multiple in the height direction is different from the multiple in the depth direction. For this reason, the data area prepared as one character multiple in the conventional method is expanded to “multiple in the height direction” and “multiple in the depth direction”.

FIG. 8 is an explanatory diagram of the data structure of the item with parentheses in one embodiment of the present invention, and shows the data structure of the item with parentheses. Reference numeral 801 denotes a conventional data structure, and reference numeral 802 denotes an extension for performing the reference position priority mode. When a multiple of the parenthesis character is obtained, a calculation for obtaining relative coordinates is performed. The horizontal coordinates of the opening parenthesis character, the formula term, and the closing parenthesis character are calculated in the same manner as in 702. The coordinates in the vertical direction are fixed to 0 in order to fix the value “0” since the reference position of the parenthesis character matches the reference position of the formula term.

FIGS. 9 and 10 are flowcharts for formatting bracketed items in one embodiment of the present invention. Next, referring to FIGS. 9 and 10, three modes of “bracketed” will be described.
I explain typesetting. When the item "with parentheses" is found in the tree structure data, the processing shown in this flowchart operates to calculate the relative coordinates and size. First, step 901
To obtain the parenthesized composition mode set as a format by the user. According to this mode, typesetting is performed in steps 902 and 90
In steps 8 and 912, the process branches to each typesetting process. Step 90
Steps 3 to 907 are the typesetting processing in the parentheses priority mode.

In step 903, the height and the depth are compared for the mathematical term of the parenthesized element. If the height is large,
In step 904, the multiple of the parenthesis character based on the height value is calculated. If the depth is large, a multiple based on the depth value is calculated in step 905. In step 906, the parentheses, formula terms, and parentheses are arranged to determine the coordinates (relative coordinates) inside the bracketed terms.

In step 907, the size of the bracketed item itself is calculated. Steps 909 to 911
Is a typesetting process in the size priority mode. Unlike the parenthesis priority mode, a multiple of the parenthesis character is calculated from the sum of the height and the depth (step 909). Step 91
In the calculation of the relative coordinates of 0, the vertical coordinates of the parentheses and the rear parentheses are placed at the center position of the vertical size of the mathematical expression.

In step 911, the size of the bracketed term is calculated. Steps 913 to 916 are for typesetting in the reference position priority mode. In this case, the reference position of the parentheses is set at the reference position of the mathematical expression as in the parenthesis priority mode. However, the size in the upward direction and the size in the downward direction from the reference position are adjusted to the height and the depth of the mathematical expression, respectively. Therefore, in step 913, a multiple in the height direction of the parenthesis character is calculated. In step 914, a multiple in the depth direction is calculated.

Thereafter, in step 915, the relative coordinates of the opening parenthesis, the formula term, and the closing parenthesis are calculated, and in step 916, the size of the term with the parenthesis is calculated. Step 917 is error processing. When the value set in the format is other than the parenthesis priority mode, the size priority mode, and the reference position priority mode, this processing is executed and the user is notified. Normally, this process is not performed.

[0047]

According to the present invention, three types of bracketing typesetting processing are prepared, and by switching the mode, the user can attach brackets as desired to the described mathematical expression. In particular, a well-balanced parenthesis can be described for those whose size in the depth direction is larger than the height direction such as a continued fraction (or vice versa).

[Brief description of the drawings]

FIG. 1 is a block diagram of a formula editing apparatus according to an embodiment of the present invention.

FIG. 2 (a) A mathematical expression syntax analysis diagram according to an embodiment of the present invention (b) A mathematical expression syntax analysis diagram according to an embodiment of the present invention (c) A mathematical expression syntax analysis diagram according to an embodiment of the present invention d) Formula syntax analysis diagram in one embodiment of the present invention

FIG. 3A is an explanatory diagram of a basic mathematical typesetting according to an embodiment of the present invention. FIG. 3B is an explanatory diagram of a basic mathematical typesetting according to an embodiment of the present invention. (D) Explanatory diagram of basic mathematical typesetting in one embodiment of the present invention

FIG. 4A is an explanatory diagram of a typesetting of a continued fraction with parentheses according to an embodiment of the present invention. FIG. 4B is an explanatory diagram of a typesetting of a continued fraction with parentheses according to an embodiment of the present invention. (D) Typesetting explanatory diagram of parenthesized continued fraction in one embodiment of the present invention (e) Typesetting explanatory diagram of parenthesized continued fraction in one embodiment of the present invention (f) The present invention Illustration of composition of bracketed continued fractions in one embodiment

FIG. 5 is a functional block diagram of a formula editing apparatus according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram of a mathematical expression data structure according to an embodiment of the present invention.

FIG. 7 is an explanatory diagram of typesetting processing in three modes according to an embodiment of the present invention.

FIG. 8 is an explanatory diagram of a data structure of a page with parentheses according to the embodiment of the present invention;

FIG. 9 is a flowchart for formatting a bracketed term according to an embodiment of the present invention;

FIG. 10 is a flowchart for formatting a bracketed term according to an embodiment of the present invention;

[Explanation of symbols]

 501 Character input section 502 Character string storage section 507 Display section 508 Format information storage section A Editing means

Claims (1)

[Claims] A display unit for displaying an edited result; a character input unit for inputting a character string forming an expression and format information on a layout of the character string; a character string storage unit for storing the input character string; A format information storage unit that stores the input format information; and an editing unit that determines the layout of the character strings in the character string storage unit by referring to the format information in the format information storage unit and displays the layout on the display unit. When the parentheses are attached to the fractional expression, the editing means matches the center position of the parentheses with the position of the fraction line, and generates parentheses that match the height of the larger of the denominator term and the numerator term of the fractional expression. A parenthesis priority mode, a reference position priority mode in which the reference position of the parentheses matches the position of the fraction line, the upper half of the parentheses matches the height of the numerator term, and the lower half of the parentheses matches the height of the denominator term, Total fractional height, independent of position Formula editing apparatus characterized by having a size priority mode for generating the combined parentheses.