Output file matrix error help?

What does the below statement mean?

Warning: Out of range or non-integer values truncated during conversion to character. > In WriteMatrixToFile at 19 In FEHW6 at 170 Error using horzcat Dimensions of matrices being concatenated are not consistent.

Error in WriteMatrixToFile (line 19) titleString = ['\n',NPVmatx,'\n'];

Error in FEHW6 (line 170) WriteMatrixToFile('d:\FEHW6.out',PQMatx);