error using open, too many input arguments. error in fopen

I have a m.file which looks something like this.

for p = 1:2
  if p==1 
    [data,txt,raw]=xlsread('subject_1.xlsx');%%this is reading file of subject 1
    fid4=fopen('new_1_datafile.dat','w');
  end
  if p==2
    [data,txt,raw]=xlsread('subject_2.xlsx'); %%%%%%reading file of subject 2
    fid4=fopen('new_2_datafile.dat','w')'
  end
  ...
  ...
  %%%written fid1,fid2,fid3 datafiles
  ...
  ...
  ...
  %%%there are lots of lines where i calculate different things for each subjects (there are 72 different %%%subjects but for simplicity i am just trying with 2). 
  fprint(fid4,.......) %%%printing out some important data
  fclose(fid1)
  fclose(fid2)
  fclose(fid3)
  fclose(fid4)
end

how can i make sure the fid4 file for the first subject is cleared before writing fid4 file for the second subject? With the above code, I am getting an error message which says, 'error using open, too many input arguments'. The error shows in line 8 when opening fid4 for second subject. So I think it is because I am opening the same file again for the second subject which has been already written for the first subject. But I have allocated different datafile name for the fid4 files for the 2 subjects. Why am I getting this error?

Answer 1

[dpb]

"error using open, too many input arguments'." clearly is bogus as an error message for fopen.

Note above it says "open" not "fopen" which means likely means there's actually a call to function open which indeed does only accept a single argument and the actual line you executed wasn't the one in the code above but something like--

fid4=open('new_2_datafile.dat','w');

NB. also above you've got a conjugate transpose operator at the end of the statement instead of a semicolon--that won't hurt anything from an operational standpoint; just echo the value and return the complex conjugate of a positive integer which is the same as the integer. I don't know what that might do in lastest releases wherein a file handle is an object instead of just a double...

Anyway, make sure you really have fopen everywhere and try again...if it fails again, post the whole error in context with the calling routine, but I'll bet you've got a typo in the m-file you executed.

[Pree]

thank you. I put open only on one of the lines instead of fopen.

[Walter Roberson]

It helps when you post the actual code, especially the code at the line that is creating the error, together with the complete error message.

Answer 2

[Hussain Baloch]

open system ('PV50')

nvals = 0;

figure

for gval=0.2:0.2:1

nvals=navals+1;

gvalsStr-num2Str(oval,3);

set_param('PV50/G1','Gain',gvalStr);

sim('PV50');

plot(v,i);

hold on

end

hold off

this is not working pls help urgently