residue error message

Hi,

I'm try to use residue function, I get the following error message

[R,P,K] = residue(M.b,M.f); Attempt to reference field of non-structure array. Error in rfdemo (line 171) [R,P,K] = residue(M.b,M.f);

[Walter Roberson]

The error means that M is a known variable but is not a structure.

Answer 1

[Image Analyst]

Set a breakpoint there at that line (learn how to use the debugger if you don't know already). Then, when it stops, type M in the command window and hit enter. See what it says. If M is a structure, it will list something like this:

M = 
    b: 10
    f: 'c:\abcdef'

If you see something else (which you probably will), then M is not a structure and you can't do things like M.b and M.f.