Traverse cell array of structures of ... in mex

3 views (last 30 days)
Peter Cotton
Peter Cotton on 15 Mar 2011
Does anyone have a nice .mex example where we pass in a cell array of struct, and interrogate fields in each structure?
This mex newby is baffled as to why mxIsStruct returns false when the following is passed a cell array of struct:
void blah(mxArray* X)
mxArray* pm;
mwIndex i;
i = 1;
pm = mxGetCell(X,i);
if (~mxIsStruct(pm)) {
mexErrMsgTxt("Not a structure");
}

Sign in to answer this question.

Accepted Answer

Jan
Jan on 16 Mar 2011
You are talking about C, not Matlab. In C the NOT operator is "!", not "~".
if (~mxIsStruct(pm)) % Bad
if (!mxIsStruct(pm)) % Good
The tilde ~ is the bitwise complement in C.
  1 Comment
Peter Cotton
Peter Cotton on 17 Mar 2011
Clunk. I sentence myself to two weeks debugging other's code.

Sign in to comment.

More Answers (3)

Jan
Jan on 16 Mar 2011
I've published two different C-Mex function which access cells and struct fields: frmfield and cstrainbp. Perhaps they help.
Kaustubha Govind
Kaustubha Govind on 15 Mar 2011
The example phonebook.c accepts an array of structs and returns a cell array - this should serve as a good starting point.
James Tursa
James Tursa on 16 Mar 2011
C is 0-based indexing. You have this in your code:
i = 1;
Are you sure you have two elements in X? Or did you mean:
i = 0;

Categories

Find more on Matrix Indexing in Help Center and File Exchange

Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!