MaplePrimes - answers and comments on Question, viewing/importing matrix/array data from maple

use a Matrix to begin with

acer — Mon, 03 Nov 2008 06:55:05 Z

Maybe you could create a Matrix inside the procedure get_quantities, instead of a table like q1, and then have that procedure assign directly to the entries of that Matrix, and have that routine also return that Matrix? Ie, right at the beginning of the procedure, insert a line like the following, and leave the rest as it is.

q1 := Matrix(4,4);

Having done it your original way, can you get the conversion of table q1 to a 4x4 Matrix like so, assuming q1's indices are valid?

Matrix(4,4,{op(map(op@lhs=rhs, op(eval(q1))))});

acer

Define Matrix First

momiji — Mon, 03 Nov 2008 06:57:41 Z

See acer's answer.

efficient export

fenghedo — Mon, 03 Nov 2008 07:57:52 Z

Thanks for the reply. Initializing the matrix works, although I made it a global variable by putting it outside the procedure. Then I could convert the matrix into matlab formats and copy them to matlab. But still I wonder if there is a better way since I have to repeat the copy and paste manually for tens of times.

I appreciate your help.

unclear

acer — Mon, 03 Nov 2008 08:19:51 Z

What exactly you are trying to do is still unclear to me.

It shouldn't make a difference whether the Matrix is a global of the procedure or is returned by that procedure, as far as subsequently exporting to Matlab formats goes.

If you do,

M := get_quantities(..blah..);

then M gets assigned the Matrix returned by get_quantities. You can deal with that as easily as with something declared as global inside the procedure.

You didn't describe cutting and pasting in the original post. You shouldn't have to resort to that, to get data from Maple into Matlab. See the ?ExportMatrix help-page, which describes how to write a Maple Matrix out to a file in Matlab format.

acer