HP Prime - Problems with adding an extra column to a matrix

[Jan_D]

I have version 2015 7 28 (8151) of the firmware and can not update it further because I have only the Android app.

I wanted to add a 4th column to a 3 by 3 matrix, which is stored in M1.

I did it this way:

ADDCOL(M1, [0,0,100], 4);       //add fourth column: [0,0,100]

Another way to do it is:

M1(1,4):=0;

M1(2,4):=0;

M1(3,4):=100;

Both ways give the same result when I look in the matrix catalog.

Also when I enter them in Home view or do some operations with it.

Strange is that in the matrix catalog the first matrix has a memory content which is about twice the memory of the second matrix.

Nothing to concern about one would say.

But when I use the first matrix in the advanced version of TRIANGLE_P it gives lines as output instead of triangles, and the second behaves normally.

I seems to me that there is something wrong with the ADDCOL command.

[Tim_Wessman · Accepted solution]

I beleive this was already corrected past the 8151 so should be in there when/if the android version is updated.

[Jan_D]

Thank you. Would be nice.

[Jan_D]

I have now updated version 8151 to the most recent version: 11226, but I have the same problems as before.

Apart from the first matrix now not giving lines as output but giving no output at all, and the second behaving normally, but maybe my present version of the program is a bit different from the earlier one.

[Tim_Wessman]

Ok. My apologies for misreading. Yes, there was a problem here. It was converting to a complex matrix which in the case of a triangle call did make a difference as it treats complex different then normal. I know this was fixed shortly after the release build (I think about 20 revisions later).

Will definitely be in the next version when/if there is one.

[Jan_D]

This seems plausible to me, because, when starting from a real matrix, and changing one of its elements from let’s say 1 to i, and then later again back from i to 1, this procedure results in a memory increase comparable to the one caused by the ADDCOL command.

[Maké]

Hi!, Jan_D:

Syntax: ADDCOL(matrix name, vector, column number)

Other mode without store original matrix ...