Updating the signal data type in .mat timeseries data

I am using Simulink Signal Editor block in Test Harness for MBD-Unit testing.

after importing test cases data(time series format) in Signal Editor block(.mat file is source file for signal data(time series format) for the Signal Editor Block), we have to open test harness each time if we want to change the data type of a signal, so I have been searching for MATLAB code that could help me change the data types of a signal directly in .mat file but no luck so far.

Can any one help me with this?

[dpb]

"...change the data types of a signal directly in .mat file"

Can you more fully explain what you're needing and attach a (smallish) example .mat file?

If you mean to change a double to a single in a .mat file, that is only possible by reading the variable from the .mat file, converting it to whatever other datatype is desired and then re-saving it.

save will overwirte an existing variable in a .mat file with the new content, effectively changing its type, but it can't be done with an typecast() while the variable is in the file, only on a copy in memory.

Does

x=rand(10,1);
y=sqrt(x);
whos

  Name       Size            Bytes  Class     Attributes

  x         10x1                80  double              
  y         10x1                80  double              

save test
whos -file test

  Name       Size            Bytes  Class     Attributes

  x         10x1                80  double              
  y         10x1                80  double              

y=single(y);
save test y -append     % must append or will wipe out x leaving only y
whos -file test

  Name       Size            Bytes  Class     Attributes

  x         10x1                80  double              
  y         10x1                40  single              

do what you're looking for?