implementation details - How to interpret the FullForm of a SparseArray?

SparseArrays are atomic objects, but they do have a FullForm which reveals information about them.

What is the meaning of the various elements in the full form of a SparseArray? Did the structure change between Mathematica versions, and is it documented anywhere?

Update: In recent versions of Mathematica the LibraryLink documentation has a useful description of the internal SparseArray structure.

Answer

I have described the details here and here. The second post describes the version number of the sparse array implementation, which is still at version 1. So no big changes since it's introduction and V9.

If you like to read about sparse arrays I can recommend this from Tim Davis.

Comments

functions - Get leading series expansion term?

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front end - keyboard shortcut to invoke Insert new matrix

I frequently need to type in some matrices, and the menu command Insert > Table/Matrix > New... allows matrices with lines drawn between columns and rows, which is very helpful. I would like to make a keyboard shortcut for it, but cannot find the relevant frontend token command (4209405) for it. Since the FullForm[] and InputForm[] of matrices with lines drawn between rows and columns is the same as those without lines, it's hard to do this via 3rd party system-wide text expanders (e.g. autohotkey or atext on mac). How does one assign a keyboard shortcut for the menu item Insert > Table/Matrix > New... , preferably using only mathematica? Thanks! Answer In the MenuSetup.tr (for linux located in the $InstallationDirectory/SystemFiles/FrontEnd/TextResources/X/ directory), I changed the line MenuItem["&New...", "CreateGridBoxDialog"] to read MenuItem["&New...", "CreateGridBoxDialog", MenuKey["m", Modifiers-...

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