problem with function argument

i try to run a function but i receive this error: The third argument must be a real, double-precision scalar.

the function code is:[spktimes, nspikes] = SGfast([dt, nrep], rate, {deadtime, refracparams})

[Image Analyst]

Duplicates with http://www.mathworks.com/matlabcentral/answers/89282-undefined-function-sgfast-for-input-arguments-of-type-cell

[Image Analyst]

Is there some reason why you posted this again when you accepted Jan's answer on the duplicate question you posted hours ago? If not, then let me know and I'll delete this question.

[Nima]

sorry i think i made a mistake. i accepted the Jan's answer for the another question and wrote the new question again on the comments

Answer 1

[Image Analyst]

Well, it's not. It's a cell array. Why are you passing in two cells instead of the single scalar number like it wants?

[Nima]

actually i dont know about cell arrays and function is written by someone else and i just want to use it in my case. so please tell me what exactly i should do with this

[Image Analyst]

If you don't know anything about cell arrays, then why did you create one? See the FAQ: http://matlab.wikia.com/wiki/FAQ#What_is_a_cell_array.3F. You need to look at the function or the help for it to figure out how to call it - that's just standard programming practice.

Answer 2

[Walter Roberson]

You (or someone) are accidentally misreading the documentation. In the place it says

[spktimes, {nspikes}] = SGfast([dt, nrep], rate, {deadtime, refracparams})

what it is trying to say is that nspikes and deadtime and refracparams are optional. If you want to use them then invoke with

[spktimes, nspikes] = SGfast([dt, nrep], rate, deadtime, [C0, S0, C1, S1])

[Nima]

i tried to call function in a way you mentioned: [spktimes, nspikes] = SGfast([dt, nrep], rate, deadtime, [C0, S0, C1, S1]); but i recieve this error: Error using SGfast Requires two or three input arguments.

[Walter Roberson]

You might need to update your SGFast. The .zip is at http://www.urmc.rochester.edu/labs/carney-lab/publications/res/SGfast_MEX_files_Updated_08_2011.zip

[Nima]

tried with the updated one but i got the same error:

Error using SGfast

Requires two or three input arguments.

[Walter Roberson]

The problem is something to do with the MEX code, not the way you are calling it if you use the code I show above.

Use

which -all SGfast

to check to be sure you are getting the correct SGfast.mex* file. Also, execute

clear SGfast

to ensure you do not have a version "stuck" from before.

Answer 3

[Adam Peterson]

I just encountered this same problem today, and it seems there is a bug in the current version of the function. Just edit the file "SGfast.c" and change lines 75 and 76 to the following:

if ( (nrhs < 2) || (nrhs > 4) )  
  mexErrMsgTxt("Requires two, three, or four input arguments.");

Then recompile the file as normal using the mex command:

mex SGfast.c

This seems to fix the problem.