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colon equivalence when deleting elements

From: John W. Eaton
Subject: colon equivalence when deleting elements
Date: Mon, 13 Oct 2003 11:00:15 -0500

There is a current thread in comp.soft-sys.matlab about the subtleties
of indexing when deleting elements of a matrix.  For example, in

  a = 1; a(:,:) = []

results in a 0x1 empty matrix.  This doesn't make much sense to me,
but apparently it is working one dimension at a time or something.

Also, the following

  a = 1;  a(1,1) = []

is not allowed ("Indexed empty matrix assignment is not allowed).
Apparently at least one of the indices must be a colon.

Octave currently checks to see if the index is equivalent to a colon
operator (i.e., it enumerates all possible indices) and if so, works
the same as if a colon had been used.

Should Octave be changed to be exactly compatible for these cases?


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