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Can't apply Differences[] to a SparseArray[]?

• To: mathgroup at smc.vnet.net
• Subject: [mg99312] Can't apply Differences[] to a SparseArray[]?
• From: jmay <jason.may at gmail.com>
• Date: Sat, 2 May 2009 06:01:10 -0400 (EDT)

Mathematica newbie here.

I'd like to apply the Differences[] function to a sparse array.  Other
list operations appear to work, but I'm seeing this:

    s = SparseArray[{5, 6, 7} -> {10, 11, 12}]

    Differences[s]

        Differences::list: List expected at position 1 in Differences
[SparseArray[Automatic,{7},0,{1,{{0,3},{{5},{6},{7}}},{10,11,12}}]].

What is special about Differences?  I don't want to convert the sparse
array to a regular list; my data set could have thousands or millions
of missing elements.

Thanks,
-Jason

• Follow-Ups:
  • Re: Can't apply Differences[] to a SparseArray[]?
    • From: Andrzej Kozlowski <akoz@mimuw.edu.pl>