How to read .txt file which have complex numbers and how to separate real and imaginary parts of the complex numbers?

I have been trying to load .txt file which is attached with this post. Actually my task has two parts:

a) How I can read the .txt file which comprised of complex numbers?

Note:

I have been trying with textread command but it is assigning the real and imaginary part of the complex number in different rows. Actually I want both real and imaginary part of the complex number in a same cell.

b) How can I sepaarte the real and imaginary part and put them in separate columns?

[Stephen23]

Note to future readers: according to the textscan documentation space characters surrounding the + and - characters within the complex numbers are not processed. The first of these characters causes textscan to quit after reading only two values from the file (as I showed here).

Answer 1

[KSSV]

fid = fopen("smithchartall.txt") ; 
S = textscan(fid,'%f %f %f\n','HeaderLines',1) ; 
fclose(fid) ; 
C1 = S{1} ; C2 = S{2} ; C3 = S{3} ; 
% Seperate real and imaginary 
C2_real = real(C2) ; 
C2_imainary = imag(C2) ; 

[Stephen23]

Fails to read the complete file:

>> S{:}
ans =
    0.1000
ans =
    0.9794
ans =
   Empty matrix: 0-by-1

This is due to the whitespace within the complex numbers, which causes textscan to quit.

"Do not include embedded white space in a complex number. textscan interprets embedded white space as a field delimiter."

source: https://www.mathworks.com/help/matlab/ref/textscan.html

Answer 2

[Stephen23]

1.

Remove the space characters embedded in the complex numbers:

opt = {'MultipleDelimsAsOne',true,'HeaderLines',1};
str = fileread('smithchartall.txt');
str = regexprep(str,'(\d)\s([-+])\s(\d)','$1$2$3');
out = textscan(str,'%f%f%f',opt{:});
out = [out{:}];

2.

Separate complex numbers into real and imaginary parts:

doc real
doc imag

[Stephen23]

>> out
out =
   0.1000             0.9794 - 0.1131i   0.9874 - 0.1569i
   0.1010             0.9793 - 0.1142i   0.9872 - 0.1584i
   0.1020             0.9792 - 0.1153i   0.9869 - 0.1600i
   0.1030             0.9790 - 0.1165i   0.9866 - 0.1615i
   0.1040             0.9789 - 0.1176i   0.9864 - 0.1631i
   0.1050             0.9787 - 0.1187i   0.9861 - 0.1646i
...
   3.9950            -0.7727 - 0.5985i  -0.7613 - 0.5993i
   3.9960            -0.7727 - 0.5983i  -0.7614 - 0.5991i
   3.9970            -0.7728 - 0.5981i  -0.7615 - 0.5990i
   3.9980            -0.7729 - 0.5979i  -0.7616 - 0.5989i
   3.9990            -0.7730 - 0.5978i  -0.7617 - 0.5987i
   4.0000            -0.7731 - 0.5976i  -0.7618 - 0.5986i

Answer 3

[Maaz Salman]

Thank you guys.

Both of the codes suggested by you guys work fine.

[Stephen23]

KSSV's code always fails for me, I tried on three MATLAB releases:

>> S{:} % R2009b:
ans =
    0.1000
ans =
    0.9794
ans =
   Empty matrix: 0-by-1
>> S{:} % R2012b
ans =
    0.1000
ans =
    0.9794
ans =
   Empty matrix: 0-by-1
>> S{:} % R2015b
ans =
    0.1000
ans =
    0.9794
ans =
   Empty matrix: 0-by-1

What OS and MATLAB version are you using?

[Maaz Salman]

I am using Windows 10 and Matlab R2018b version.

In my case both codes are working just fine.

Actually, I want to plot these data on smith chart using Origin.

Therefore, I need to separate the real and imaginary part of all the complex numbers given in the .txt file.