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How do I read a file with complex data (real + imaginary) into a vector?

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Irfan Mohideen
Irfan Mohideen on 11 Dec 2019
Commented: Irfan Mohideen on 17 Dec 2019
I have a file with 100 rows of complex data with variable column size. How do I read it into a vector of 70: [] ?
If row 1 is bigger than row 2, then I like the row 1 padded by default (like in dlmread).

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Irfan Mohideen
Irfan Mohideen on 12 Dec 2019
It should look like this.
1.868-0.52591i -0.4178+1.0316i 0.5408-0.74036i -0.024144+1.6425i -0.34343+0.96012i
0.33257-0.20658i -0.56193-1.6297i -0.3833+0.555i 0.58934-0.053148i 0.18756-0.53192i -1.0676+0.88013i
0.6894+0.60439i 1.2882+0.12116i 1.0911+0.40315i -0.63711-0.91396i -0.70589+0.54294i -0.28131+0.41173i
0.36288+1.0868i -0.7524+0.72005i -1.8897+0.25002i 1.3212+1.9887i

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Answers (1)

per isakson
per isakson on 12 Dec 2019
Edited: per isakson on 12 Dec 2019
What problem do you encounter? With R2018b dlmread() reads your small data set nicely. Padding is done with 0+0i
>> C = dlmread( 'data.txt' )
C =
Columns 1 through 3
1.868 - 0.52591i -0.4178 + 1.0316i 0.5408 - 0.74036i
0.33257 - 0.20658i -0.56193 - 1.6297i -0.3833 + 0.555i
0.6894 + 0.60439i 1.2882 + 0.12116i 1.0911 + 0.40315i
0.36288 + 1.0868i -0.7524 + 0.72005i -1.8897 + 0.25002i
Columns 4 through 6
-0.024144 + 1.6425i -0.34343 + 0.96012i 0 + 0i
0.58934 - 0.053148i 0.18756 - 0.53192i -1.0676 + 0.88013i
-0.63711 - 0.91396i -0.70589 + 0.54294i -0.28131 + 0.41173i
1.3212 + 1.9887i 0 + 0i 0 + 0i
>>
where data.txt contains the data of your comment,
"a vector of 70: [] ?"
D = reshape( C, 6,[] ); % I replaced 70 by 6 to match this small data set
"If row 1 is bigger than row 2, then I like the row 1 padded"
You don't mean to pad the "bigger" row?
In response to comments
This script does for the large file what dlmread() did for the small file
%%
fid = fopen( 'd:\m\cssm\BerNoisySignal.dat', 'rt' );
cac = cell(0,1);
while not( feof( fid ) )
chr = fgetl( fid );
cac{end+1,1} = textscan( chr, '%f', 'Delimiter','\t' );
disp( length(cac) ) % show progress
end
fclose( fid );
%%
wid = max( cellfun( @(c) numel(c{1}), cac ) );
C = complex( zeros( length(cac), wid ) );
%%
for jj = 1 : length(cac)
num = reshape( cac{jj}{1}, 1,[] );
C(jj,1:length(num)) = num;
end
%%
figure,imagesc(real(C))
outputs
and
>> C(30:35,1e5:1e5+2)
ans =
0.473 + 0.24055i -0.10531 + 0.21882i 0.60661 + 0.44345i
0.30427 + 0.43949i 0.75655 - 1.0476i 0.20642 + 0.40645i
0.82177 - 0.10199i 0.17799 + 0.10666i 0.44184 + 0.88519i
0.29776 - 0.44033i -0.25417 + 0.0089458i -0.048546 + 0.9869i
0.96475 + 0.48504i -0.58236 - 0.7256i -0.019985 - 0.6513i
1.1374 - 0.1369i 0.19644 - 0.021786i -1.0417 - 0.55171
>> C(28:33,wid-2:wid)
ans =
0 + 0i 0 + 0i 0 + 0i
0 + 0i 0 + 0i 0 + 0i
-0.22192 + 0.68818i -0.91552 - 0.17804i -0.2485 + 0.90526i
0 + 0i 0 + 0i 0 + 0i
0 + 0i 0 + 0i 0 + 0i
0 + 0i 0 + 0i 0 + 0i
and
>> D = reshape( C, 70,[] );
>> whos C D
Name Size Bytes Class Attributes
C 35x155000 86800000 double complex
D 70x77500 86800000 double complex

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per isakson
per isakson on 12 Dec 2019
"or if you go Here Link you can download" that suits me better.
I've added a script to my answer.

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