Two ways

Preben Alsholm — Mon, 14 Jan 2013 21:00:37 Z

Here are two ways to do the manipulation. The second in three versions.

restart;
A:=LinearAlgebra:-RandomMatrix(1021,2); #Example matrix (array)
f:=(x,y)->x+2*y; #Example function
E:=zip(f, A[..,1], A[..,2]);
E[1..5];
M:=convert(E,Matrix); #May be needed for the export.

#A more straightforward way in 3 versions:
#Here the first column is kept intact:
B1:=Matrix(1021,2,(i,j)->if j=2 then f(A[i,1],A[i,2]) else A[i,j] end if);
A[1..5,1..2];
B1[1..5,1..2];
#Here the two first columns are intact but a third added:
B2:=Matrix(1021,3,(i,j)->if j=3 then f(A[i,1],A[i,2]) else A[i,j] end if);
B2[1..5,1..3];
#And this one only contains the results:
B3:=Matrix(1021,1,(i,j)->f(A[i,1],A[i,2]));
B3[1..5,1];

f(x,y) values as third column

Adri van der Meer — Mon, 14 Jan 2013 21:22:22 Z

If you want the results as the third column in the excelsheet, you can do

Q := Import( "Test.xls",1, "A1:B20" );
f := (x,y) -> 2*x+y;
C := f~(Q[..,1],Q[..,2]);  # a short alternative for zip
Export( C, "Test.xls", 1, "C1" );

Edited:
I didn't see Preben Alsholms answer.

MaplePrimes - answers and comments on Question, Problems with Excel import

Two ways

f(x,y) values as third column