This is my first effort at Custom Functions so be kind.

I am working with the example file Matrix Math from

http://www.spf-15.com/fmExamples/

and some of the functions below are from that file. I have defined a custom function AddRow which simply adds a new row into a matrix at a given position (the position is the row number of the vector in the new matrix. AddRow is defined as

AddRow(matrix,row,vector) =

Case(

Cols(matrix) ≠ Cols(vector) or Int(row) ≠ row or row > Rows(matrix) + 1 or row ≤ 0;matrix;

LeftValues(matrix;row - 1) & vector & If(row ≠ Rows(matrix) + 1; "¶";"") & RightValues(matrix;Rows(matrix) - row + 1 ))

Here vector is a list in the form v = "a1; a2; ... ; an;" Cols(v) = n and matrix is a value list of vectors A = v1 & "¶" & v2 & "¶" &... &vm) all with the same number of columns and Rows(A) = m.

THis function works fine.I need a similar function AddCol to add a column to a matrix in a given position and it seemed to me that the obvious thing to do was to use Transpose and AddRow.

So I am trying to add a column whose elements are from a given (row) vector

AddCol(matrix;col;vector) =

Transpose(AddRow(Transpose(matrix);col;vector))

OK here is the problem. AddCol does not work FMP gives me the ? However, if I write down the formula for AddCol above and Evaluate it it does work. Am I missing something about custom functions calling custom functions?

Any help appreciated.

Ignore this post - I don't know what I was doing when I tested it but it works fine now.