Updates:
Labels: smichr NeedsReview
Comment #24 on issue 884 by [email protected]: One line matrix and one
column matrix confusion
http://code.google.com/p/sympy/issues/detail?id=884
OK, I found this issue after trying to use the Matrix object the other day.
There is presently and inconsistent handling of arguments between Matrix
and SparseMatrix, the latter allowing `(1,2,3)` as shorthand for `([1, 2,
3])` which is shorthand for `([[1], [2], [3]])`. `Matrix(1,2,3)` just
raises an error. I would really like to have Matrix behave like other sympy
containers which dispense with the outer brackets:
Set(1,2,3)
Tuple(1,2,3)
Dict((1,2),(3,4)) # in the works
Matrix should behave similarily with the mental mnemonic that the arguments
you list are the rows of the Matrix
Matrix(1,2,3) # row 1 is 1, row 2 is 2, row 3 is 3
[1]
[2]
[3]
Matrix([1,2,3]) # row 1 is [1, 2, 3]
[1, 2, 3]
Matrix([1,2,3],[4,5,6]) # two rows
[1, 2, 3]
[4, 5, 6]
The problem is that I don't know how to maintain backward compatibility if
this change were made since Matrix([1,2,3]) would be impossible to
interpret as being the old shorthand for a column vector or the new method
of giving single row with three columns.
Anyway, we can allow Matrix to at least behave like SparseMatrix and allow
the Matrix(1,2,3) to work.
https://github.com/sympy/sympy/pull/580
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