Hi, while I was testing the SVAR addon I ran into a bug that has its roots in gretl. The code below shows the problem, namely that even though the function hey() officially returns a matrix, if it's a 1x1 matrix _and_ if the caller does not explicitly cast the output to a matrix type (with the 'matrix' alias for genr), then gretl puts the return value into a scalar type. And if the caller then wants to use this variable as a matrix (because that's what it's supposed to be), it fails. So I think gretl should honor the return type of a user-defined function always. I know that sometimes gretl has to convert a 1x1 matrix to a scalar, for example if vec(a)'vec(a) is treated by the programmer as a number for further stuff. But somehow gretl does it prematurely here. thanks, sven <hansl> function void hu(matrix *m) print "ouf" end function function matrix hey(bool in) if in return zeros(2,2) else return zeros(1,1) endif end function out2 = hey(1) hu(&out2) # works matrix out3 = hey(0) hu(&out3) # works out = hey(0) hu(&out) # fails, wrong argument type </hansl>