How to replace multiple strings in a txt file

Hi,

I would like to couple matlab to a another program so I can make a lot of models in a fast way. To do so, I need a txt file with commands in which I can modify some strings with Matlab. For example, in the txt file the commands are written...

*add_points
3
0
x1
0
0
x2
5
0
3
5
0
*set_curve_type line
*add_curves
 50
 49
 49
 52
 52
 51
*set_curve_type fillet
*add_curves
 23
 24
x3

..... and the idea is to replace x1,x2 and x3 with the values from A in which A is a 10*3 matrix and x1=A(1,:) and x2=(2,:) and x3=A(3,:).

So I have 10 text files to make the 10 models.

My question is: how to do this? I tried to use commands as txtscan, strrep but that didn't work for me...

Any suggestions? What would be the most easy way?

Thanks in advance!

Steven

Answer 1

[Sven]

Hi Steven,

Try this, it's basically 3 steps:

1. Read the file into a cell of strings (1 per line in the original file)
2. Replace the keywords via a regexprep
3. Save the new file

Does it work for you?

linesCell = cell(10000,1);
fid=fopen('myFile.txt');
lineNo = 0;
while 1
    lineNo = lineNo+1;
    linesCell{lineNo} = fgetl(fid);
    if ~ischar(linesCell{lineNo}), break, end
end
fclose(fid);
linesCell(lineNo:end) = [];

A = rand(3,1);
for i = 1:size(A,1)
    linesCell = regexprep(linesCell,sprintf('x%d',i),sprintf('%f',A(i)));
end

fid=fopen('myFileOut.txt','wt');
fprintf('%s\n',linesCell{:});
fclose(fid)

[steven grob]

I added fid in

fprintf(fid,'%s\n',linesCell{:});

but it works perfect now!

Thanks Sven

[Sven]

Ah, yep - typo, but you got it. Glad it helped.