QtiPlot is a program for two- and three-dimensional graphical 
presentation of data sets and for data analysis. Plots can be produced
from data sets stored in tables or from analytical functions. QtiPlot 
offers a complete alternative solution to software like Origin, 
SigmaPlot, SPSS, Regressi or Igor Pro. QtiPlot is used for teaching as
well as for complex data analysis and visualisation in companies, high
schools, universities and reseach institutes all over the world.

Features:

- Fully Python scriptable
- OpenGL based 3D plotting
- Publication quality plots and easy export to various image formats 
  (EMF, EPS, PS, PDF, SVG, BMP, JPG, PNG, TIFF, etc ...)
- Easy integration with LaTeX typesetting system
- Powerful and versatile spreadsheets with column-logic calculations 
  and easy import/export of multiple files
- One-click access to extensive built-in data analysis routines
- Advanced statistical analysis: Student's t-Test, ANOVA, chi-square 
  test for variance, normality test (Shapiro-Wilk)
- Linear and nonlinear curve fitting with weighting and estimation of 
  statistical errors of the fit-parameters
- Multi-peak fitting
- Image analysis tools
- Templates support: all settings for plots, tables and matrices can 
  be saved and restored later on for a fast editing process
- Project files based on folders, a powerful project explorer with 
  built-in drag and drop and searching facilities

QtiPlot comes with its own, slightly modified versions of qwt and
qwtplot3d, while the script additionally builds in QTeXEngine and the
unofficial importOPJ plugin.
