https://github.com/mzur/pretty-formula

A small Java library to parse mathematical formulas to LaTeX and display them as images
https://github.com/mzur/pretty-formula

formula images java latex

Last synced: 2 months ago
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A small Java library to parse mathematical formulas to LaTeX and display them as images

• Host: GitHub
• URL: https://github.com/mzur/pretty-formula
• Owner: mzur
• License: mit
• Created: 2014-12-04T15:55:44.000Z (about 10 years ago)
• Default Branch: master
• Last Pushed: 2014-12-04T16:59:41.000Z (about 10 years ago)
• Last Synced: 2024-05-02T01:10:56.989Z (9 months ago)
• Topics: formula, images, java, latex
• Language: Java
• Size: 4.47 MB
• Stars: 31
• Watchers: 2
• Forks: 8
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.txt

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README

        
# pretty-formula

A small Java library to parse mathematical formulas to LaTeX and display them as images.

Formula:

```

(a_1 / (b_1 + sqrt(c))^2) + sin(a_2 * b_2)

```

Image:

![example](example.png?raw=true)

LaTeX:

```latex

\left(\frac{{a}_{1}}{{\left({b}_{1}+\sqrt{c}\right)}^{2}}\right)+\sin{\left({a}_{2}\cdot {b}_{2}\right)}

```

## Installation

Grab the latest release and add the `pretty-formula.jar` as well as all the dependencies from the `lib` directory to your project.

## Usage

Pretty-formula provides three functions to parse mathematical formulas either to LaTeX or to bitmap/vector graphics. It provides a basic GUI as an example how to use it as well. This means you even can run `pretty-formula.jar` on its own!

All the following functions are located in the package `de.uni_bielefeld.cebitec.mzurowie.pretty_formula.main`.

### String parseToLatex(String formula)

Parses a mathematical formula String like `(a+b)/c` to valid math LaTeX.

`formula`: A raw formula input String.

**Returns:** The formula parsed to a small subset of LaTeX.

**Throws:** `DetailedParseCancellationException` When the parsing fails.

### BufferedImage parseToImage(String formula)

Parses a mathematical formula String like `(a+b)/c` to a pretty image.

`formula`: A raw formula input String.

**Returns:** An image object containing the rendered formula.

**Throws:** `ParseException` When the formula rendering fails.

**Throws:** `DetailedParseCancellationException` when the formula parsing fails.

### void saveToSVG(String formula, File file)

Parses a mathematical formula like `(a+b)/c` to a pretty image and saves it as an SVG file.

`formula`: A raw formula input String.

`file`: The SVG file to save to.

**Throws:** `ParseException` When parsing the LaTeX formula failed.

**Throws:** `IOException` When writing the file failed.

**Throws:** `DetailedParseCancellationException` When parsing the raw formula to LaTeX failed.

## Example

You can find the fully working GUI example in [`GUIWindow.java`](src/de/uni_bielefeld/cebitec/mzurowie/pretty_formula/main/GUIWindow.java). To run it, simply execute `pretty-formula.jar`.

The important part of parsing the formula to an image and do error handling and user feedback is this:

```java

private void jTextPane1KeyReleased(java.awt.event.KeyEvent evt) {

	// feedback message

   this.jLabel1.setText("");

   

   // clear previously drawn formula

   this.jLabel2.getGraphics().clearRect(0, 0, this.jLabel2.getWidth(), this.jLabel2.getHeight());

   // remove error highlights from user input

   this.jTextPane1.getHighlighter().removeAllHighlights();

   try {

   	// parse the image

      BufferedImage image = FormulaParser.parseToImage(this.jTextPane1.getText());

      // display the image

      this.jLabel2.getGraphics().drawImage(image, 0, 0, null);

      

   } catch (DetailedParseCancellationException e) {

     // display user feedback on erroneous input

     this.handleDetailedParseCancellationException(e);

   } catch (ParseException e) {

   	// display user feedback on erroneous parsing (shouldn't happen, though)

      this.jLabel1.setText(e.getMessage());

   }

}

private void handleDetailedParseCancellationException(DetailedParseCancellationException e) {

   try {

      // highlight the position at which the error occurred

      this.jTextPane1.getHighlighter().addHighlight(

              e.getCharPositionInLine(), e.getEndCharPositionInLine(),

              this.errorHighlighter);

   } catch (BadLocationException ex) {

      // simply don't highlight

   }

   // display the error message in addition to the error highlighting

   this.jLabel1.setText(e.getMessage());

}

```