On these sites there exist already introductions to Gnuplot, but I want to do it in a slightly different way that concentrates on the way I’m using Gnuplot.
And this way means, that I will present no introduction to the interactive Gnuplot prompt, but will start directly with writing some text files. These files can then be executed by Gnuplot.

Manually labeling features in a crowed plot can be very time consuming. Functions in this module can be used to automatically place labels without the labels overlapping each other. This is useful, for example, in creating plots of spectrum with lines identified with labels.

Line Identification Plots v0.1 documentation
Line identification plots with automatic label layout

This module has functions for automatically placing labels in a plot in such a way that the labels do not overlap with each other. This is very useful, for example, in creating plots that have labels identifying features in a spectrum.

xyscan is a tool for scientist in the need to extract data points, i.e. numeric values, from a plot. It allows to scan the plots and extract data points including the size of the error bars (both in x and y). It can handle plots with linear and logarithmic scales. In fact xyscan can be used for extracting numeric values from any kind of 2D technical drawings.

APLpy (the Astronomical Plotting Library in Python) is a Python module aimed at producing publication-quality plots of astronomical imaging data in FITS format. The module uses Matplotlib, a powerful and interactive plotting package. It is capable of creating output files in several graphical formats, including EPS, PDF, PS, PNG, and SVG.

After I’ve covered basic plotting using matplotlib in this part I’ll show you two ways to display histograms of some data.

Veusz is a scientific plotting and graphing package written in Python. It uses PyQt (Wiki) and Numpy. Veusz is designed to produce publication-ready Postscript/PDF output. Veusz runs under Unix/Linux, Windows and Mac OS X.

SM is a plotting programme written by Robert Lupton (

APLpy (the Astronomical Plotting Library in Python) is a Python module aimed at producing publication-quality plots of astronomical imaging data in FITS format. The module uses Matplotlib, a powerful and interactive plotting package. It is capable of creating output files in several graphical formats, including EPS, PDF, PS, PNG, and SVG.

We describe a new library (AST) which provides a flexible high-level programming interface for handling world coordinate systems in astronomy and for producing graphical output. It includes, but is not limited to, a wide range of celestial coordinate systems and supports the Digitised Sky Survey plate solutions and the draft FITS WCS proposals amongst other possibilities. AST is portable and environment independent.