Using xlsread with the MATLAB Engine

I am trying to use the xlsread function in matlab through the MATLAB engine. I was trying to use engEvalString() to implement it, however it is returning 0 every time that I try to implement it so I don't think that I am using engEvalString() correctly. Right now this is how I am trying to implement it:

engEvalString(ep, "[num, text, raw] = xlsread(\"C:\\Users\\rest_of_filename_path\")")

Any feedback that anyone could provide would be great, Thanks!

Answer 1

[James Tursa]

Please explain "returning 0". Is the engEvalString call itself returning 0? If so, that is good because that is the normal state. Are you really using double quotes inside your eval string? I would have thought single quotes would be required. E.g., something like this:

engEvalString(ep, "[num, text, raw] = xlsread('C:\\Users\\rest_of_filename_path\')")

Then use engGetVariable to get num, text, and raw.

[Caroline]

I changed the double quotes to single quotes but when I use engGetVariable() it is returning 00000000 for num, text and raw. I know that engGetVariable() is supposed to return a memory location so the fact that engGetVariable() is returning 00000000 doesn't seem right. I used engGetVariable() in the following way:

engGetVariable(ep, "num"); engGetVariable(ep, "text"); engGetVariable (ep, "raw");

Could this mean that something is wrong when the file is being read?

Thank you for your help!

[James Tursa]

Try this:

- Open the Engine

- Use engEvalString to do the xlsread stuff

- Pause or close your program, but DO NOT use engClose in your program ... i.e. leave the Engine running.

- Manually click on the Engine window and then see what is in the workspace (i.e. see if there are num, text, and raw variables there with the expected values). I.e., use the whos command etc to examine the workspace.

If the num, text, and raw variables are there with the expected values then the problem is with your engGetVariable code. If the variables are not in the workspace then the problem is with your xlsread and you will have to debug that.

In your engGetVariable code, aren't you assigning the results to variables? If so, you don't show it. E.g., something like this is what I would have expected:

mxArray *num, *text, *raw;
    :
num = engGetVariable(ep, "num"); 
text = engGetVariable(ep, "text"); 
raw = engGetVariable (ep, "raw");

[Caroline]

Thank you!