I have a function called "rfun(x,y) that calculates a dimensionless reaction rate. The function works fine when calculating a single
value, but when it appears in a program function used to create a matrix of rates for x and y vector inputs, it doesn't work properly.
All elements of the resulting matrix contain the same value which corresponds to the last value calculated. See below.



I found a workaround as shown in the next image. All of the elements produced by these two functions are correct.



Can anyone explain why the first method doesn't work? If I try this method with simpler functions, it works fine. The rfun function involves some use of the Prode Physical properties which may be a cause. However, since the rfun function works fine for a single result, I don't understand why it doesn't work here. Also, the rfun function doesn't work in Maxima Draw3d either.

Also, is there a more elegant workaround that could be done in just one program function?

No document = No monkey see no monkey do

I found a solution. When I create the rfun function, I do it with a program. The first line of the program is a Clear() statement that clears the output of the rate function. The second line is the result = math expression, and the last line is the result variable for the output.

I had previously tried using clear statements in the matrix creation function with no success.

Wrote

I had previously tried using clear statements in the matrix creation function with no success.

When re-using matrix/vector in program, set [M, V]:=0