GrainSizeTools script manual

This is the manual for the GrainSizeTools script. GrainSizeTools script is a free open-source cross-platform script written in Python that provides a number of tools with the aim of characterizing the grain size and the actual population of grain sizes in dynamically recrystallized rocks. The script is suitable to use in paleopiezometry studies, returning different 1D grain size measures, as well as to derive the actual 3D population of grain sizes from thin sections using two methods: the Saltykov and the two-step methods. The script only requires the previous measurement of the grain sectional areas from a thin section. There is no need of previous knowledge of Python language to use the script and get the results. For advanced users, the script is organized in a modular way using Python functions, which facilitates to modify, reuse or extend the code if needed.