Hello, I am interested in altering a model that I've put together and run earlier using simulink. It's simply a two-input plant, with scope output; earlier I'd had a sine wave input, but I would like to change to a matrix(from file) as source. So I've taken a matrix from the 'source' collection, and attached it to the main part. The parameters of the main part are a 2 X 2 matrix. So the matrix I've tried to use for source from a MAT- file is 3 X 2(since the first row should be times). The help pages for simulink seem to indicate that the matrix should be transposed to run with the model. So I've transposed the matrix in the workspace. Each time I try to attach the source to the main part, the output indicates " matrix from file must have real times in increasing order(not complex)"; the help file also indicates that the time parameter in the I/O workspace pane can indicate the time variable. I'm guessing that some others may not have found this procedure exactly "hands on" as well? -S