Load text file with open braket ( )

Dear all,

I have a txt file in the format like:

(70.0362+32052.7j)

(-1.16529e-12+29239.2j)

(-1.42109e-13+26859.3j)

...

Then I used the following code:

fid = fopen('ImpedanceMatrix1.txt','r');
A = textscan(fid,'%s');
fclose(fid);
A = A{:};

However, it doesn't remove the brackets in the variable. Could you please suggest me how to do that. Thanks.

[Stephen23]

Why are you reading a file with numeric data using a string format? Why not just read the numeric data directly using a numeric format? Reading the data as a string and the post-processing (e.g. using regular expressions) is going to be quite inefficient.

[Shan Chu]

Hi sir, I am not good at Matlab. I used Load before but it doesn't work. Could you please suggest which function that I could use? Thanks

[Stephen23]

@Shan Chu: I did not write that you should use a different function. I wrote that you should import numeric data using a numeric format, not a string format: these are clearly explained in the textscan documentation. Currently you use '%s', which imports data as a string (a char vector), but instead simply import your data using %f, which will be much more efficient than what you do now. Check my answer to see how simple this is.

Answer 1

[Birdman]

Try this:

 regexprep(A,{'(',')'},{'',''})

[Shan Chu]

Thank you sir. it works perfectly

[Birdman]

You are welcome.

[Shan Chu]

Btw, I tried to use cell2mat to convert it to math type but it doesn't work. Could you please help?

[Birdman]

Just simply

 str2double(regexprep(A,{'(',')'},{'',''}))

[Shan Chu]

I see, The type is string not double. Thanks sir

[Birdman]

;-)

[Stephen23]

See my answer for a more efficient solution.

[Birdman]

Yes, I saw as usual :)

But it is only a bit of more code in my case, of course your solution is more efficient.

Answer 2

[Stephen23]

It is much more efficient to import the data using a numeric format (rather than as a string and doing post-processing as you are doing now). My test file is attached (you did not provide a sample file).

[fid,msg] = fopen('temp5.txt','rt');
assert(fid>=3,msg)
C = textscan(fid,'(%f)');
fclose(fid);

Giving:

>> C{1}
ans =
  7.0036e+001 + 3.2053e+004i
  -1.1653e-012 + 2.9239e+004i
  -1.4211e-013 + 2.6859e+004i