.. highlightlang:: us

.. index:: LaTeX
.. index:: Edit=>Insert LaTeX Formula

.. _edit-insert-formula:

Edit=>Insert LaTeX Formula
--------------------------

(`TeX <http://en.wikipedia.org/wiki/TeX>`_ is a typesetting system
designed and mostly written by 
`Donald E. Knuth <http://en.wikipedia.org/wiki/Donald_Knuth>`_.)

This command inserts `LaTeX <http://en.wikipedia.org/wiki/LaTeX>`_-formulas into
the active document page.

A formula is typed in text form as follows:

.. code-block:: none

   $$\int_{0}^{\infty} x^2 e^{-x^2} dx = \frac{\sqrt{\pi}}{4}$$

The created formula will be inserted into the document page as a high
resolution bitmap (png) with 600 dpi.

.. math::

   \int_{0}^{\infty} x^2 e^{-x^2} dx = \frac{\sqrt{\pi}}{4}

To modify the formula, double-click the bitmap with the mouse.

More documtation about Latex can be found here http://www.latex-project.org/.

Installation
^^^^^^^^^^^^

.. highlightlang:: none

Check if :command:`latex.exe` and :command:`dvipng.exe` are installed on your 
computer or if they are available on your network::

   c:\> dvipng -version

   This is dvipng 1.9 Copyright 2002-2006 Jan-Ake Larsson
   dvipng 1.9
   kpathsea version 3.3.2
   Copyright (C) 2002-2005 Jan-Ake Larsson.
   There is NO warranty.  You may redistribute this software
   under the terms of the GNU General Public License.
   For more information about these matters, see the files
   named COPYING and dvipng.c.

   c:\> latex -version

   MiKTeX-pdfTeX 2.7.3235 (1.40.9) (MiKTeX 2.7)
   Copyright (C) 1982 D. E. Knuth, (C) 1996-2006 Han The Thanh
   TeX is a trademark of the American Mathematical Society.

.. highlightlang:: us

If Latex is not installed it is recommended to in install the free Latex 
distribution MiKTeX (http://www.miktex.org) from Christian Schenk. The 
setup program can be find here: http://www.miktex.org/2.9/setup. ``dvipng.exe``
is included.

There also a portable edition of MikTeX available (http://miktex.org/portable/about).
It can be used from a USB stick without administrator privilieges.
The path to the installation can be set in the UniPlot command window
:ref:`viewcommand-window`). The following commands sets path, where ``j:``
is the drive letter of your USB stick::

   * WriteProfileString("Settings", "latex-path", "j:\\miktex\\bin");

Check the set-up::

   * _latex_find()
   j:\miktex\bin\latex.exe
   j:\miktex\bin\dvipng.exe

UniPlot saves temporary files in the user directory of UniPlot. If the path name
contains spaces it may cause problems with some TeX distributions. In this
case you can specify the name of new existing directory without spaces with the 
following command::

   * WriteProfileString("settings", "latex_temp_path", "c:/temp");
 

Example
^^^^^^^^^

.. code-block:: none

 \begin{pmatrix}
    4 & 7 \\
    2 & 5
  \end{pmatrix}
  \cdot
  \begin{pmatrix}
    x_{1} \\
    x_{2}
  \end{pmatrix}
  =
  \begin{pmatrix}
    1 \\
    4
  \end{pmatrix}

.. math::

 \begin{pmatrix}
    4 & 7 \\
    2 & 5
  \end{pmatrix}
  \cdot
  \begin{pmatrix}
    x_{1} \\
    x_{2}
  \end{pmatrix}
  =
  \begin{pmatrix}
    1 \\
    4
  \end{pmatrix}

.. code-block:: none

   You can also write normal text with Latex and include a formula 
   like the following $\sum^{n}_{k=0}\frac{k}{2}$ into the text.

You can also write normal text with Latex and include a formula 
like the following :math:`\sum^{n}_{k=0}\frac{k}{2}` into the text.

Notes
^^^^^

* The interface to Latex is written in UniScript. You find the source code in the
  file :file:`script\\drawing\\latex.ic`.

* If you insert or modify a formula for the first time it can take some minutes
  until the formula is displayed, because `MiKTeX <http://www.miktex.org>`_ will
  download packages used in the formula.

* Fomulas in Wikipaedia (see for example 
  `FFT <http://en.wikipedia.org/wiki/FFT>`_) are 
  written in Latex. The formulas in this manual are also created using Latex.
  The formulas in the UniPlot PDF manual (see 
  http://www.uniplot.de/documents/en/download.html) are completely created with
  Latex.

* In this version Latex cannot be used for axes tick labels, axes labels, table
  cells and dataset. To work around this limitation create a latex formula and
  replace the element with it.

* The UniScript interface contains the following functions (documentation is 
  missing in this version)::

     hLatex = latex_create()
     hLatex = latex_create(hLatex)
     hLatex = latex_create(ssText)
     ssText = latex_gettext(hLatex)
     bool = latex_settext(hLatex, ssText)
     bool = latex_get_rotate90(hImage)
     bool = latex_set_rotate90(hImage, bRot)
     bool = latex_check_install(bQuite)
     bool = latex_destroy(hLatex)

* Before the formula is send to Latex the following header is inserted in front
  of the formula text::

     \documentclass[12pt]{article}
     \usepackage[latin1]{inputenc}
     \usepackage{amsmath}
     \usepackage{amsthm}
     \usepackage{amssymb}
     \usepackage{bm}
     \newcommand{\mx}[1]{\mathbf{\bm{#1}}} % Matrix command
     \newcommand{\vc}[1]{\mathbf{\bm{#1}}} % Vector command 
     \newcommand{\T}{\text{T}}                % Transpose
     \pagestyle{empty} 
     \begin{document}

  The header can be modified using the :ref:`WriteProfileString` function.
  Example::

     ssHeader = "[[
     \documentclass[fleqn,12pt]{article}
     \usepackage[latin1]{inputenc}
     \usepackage{color}
     \usepackage{palatino}
     \usepackage{amsmath}
     \usepackage{amsthm}
     \usepackage{amssymb}
     \usepackage{bm}
     \newcommand{\mx}[1]{\mathbf{\bm{#1}}} % Matrix command
     \newcommand{\vc}[1]{\mathbf{\bm{#1}}} % Vector command 
     \newcommand{\T}{\text{T}}                % Transpose
     \pagestyle{empty} 
     \begin{document}
     ]]";
     WriteProfileString("Settings", "latex-header", ssHeader)

.. seealso::
   :ref:`edit`,
   :ref:`editobject-propertiespicture`,
   :ref:`@f{latex}`

:sub:`id-704693`