IDL, short for Interactive Data Language, is a programming language used for data analysis. It is popular in particular areas of science, such as astronomy and medical imaging. IDL shares a common syntax with PV-Wave and originated from the same code-base, though the languages have subsequently diverged in detail. There is also a free implementation, GNU Data Language (GDL).

IDL is vectorized, numerical, and interactive, and is commonly used for interactive processing of large amounts of data (including image processing). The syntax includes many constructs from Fortran and some from C.


This work was funded by a NERC Postgraduate and Professional Skills Development Award.

Course Author

Dr. Nigel Richards