Insertion of header in the first row of .txt file

Hi,

I need to insert below header file in the first row of the each txt file, please assist me in how to do this..

#DaVis 8.4.0 2D-vector 12 62 75 "position" "mm" "position" "mm" "velocity" "m/s"

for k = 1:1:5
UFF = X_filter(1:ni*nk,k);
VFF = X_filter(1+ni*nk:2*ni*nk,k);
UFF1 =reshape (UFF,ni,nk)';
VFF1 =reshape (VFF,ni,nk)';
UUFFF1 = reshape (UFF1, 4650,1);
VVFFF1 = reshape (VFF1,4650,1);
xxx = reshape (X,4650,1);
yyy = reshape (Y,4650,1);
fileName = sprintf('test%d.txt',k);
dlmwrite(fileName,[xxx yyy UUFFF1 VVFFF1],'delimiter','\t' );
end

[KSSV]

Read about fprintf.

[Turbulence Analysis]

Hi,

I tried as follows. It replaces my data in the test.txt file and retains only HEADER in the first row...

filename = 'test2.txt';

fid = fopen(filename,'w');

fprintf(fid, 'HEADER \n');

fclose(fid);

Answer 1

[KSSV]

Something like this should work.

filename = 'test2.txt';
fid = fopen(filename,'w');
fprintf(fid, 'HEADER \n');
fclose(fid);

for k = 1:1:5
UFF = X_filter(1:ni*nk,k);
VFF = X_filter(1+ni*nk:2*ni*nk,k);
UFF1 =reshape (UFF,ni,nk)';
VFF1 =reshape (VFF,ni,nk)';
UUFFF1 = reshape (UFF1, 4650,1);
VVFFF1 = reshape (VFF1,4650,1);
xxx = reshape (X,4650,1);
yyy = reshape (Y,4650,1);
fileName = sprintf('test%d.txt',k);
dlmwrite(fileName,[xxx yyy UUFFF1 VVFFF1],'delimiter','\t','-append');
end

dlmwrite is obselete.....read about writematrix.

[Turbulence Analysis]

Tried as below, but not successful....

for j =1:1:2

fileName = sprintf('test%d.txt',j);

fid = fopen(filename,'w');

fprintf(fid, 'HEADER 1 \n');

fclose(fid);

end

for k = 1:1:2

UFF = X_filter(1:ni*nk,k);

VFF = X_filter(1+ni*nk:2*ni*nk,k);

UFF1 =reshape (UFF,ni,nk)';

VFF1 =reshape (VFF,ni,nk)';

UUFFF1 = reshape (UFF1, 4650,1);

VVFFF1 = reshape (VFF1,4650,1);

xxx = reshape (X,4650,1);

yyy = reshape (Y,4650,1);

fileName = sprintf('test%d.txt',k);

dlmwrite(fileName,[xxx yyy UUFFF1 VVFFF1], 'delimiter','\t' );

end

[KSSV]

What happened to the code which I gave? You have to append the data to the existitng file..or use fprintf for wrtitng header file as well as the matrix.

[KSSV]

OP commented:

Hi,

It's working now.. Thanks for the hint..

for k = 1:1:100
filename = sprintf('test%d.txt',k);
fid = fopen(filename,'w');
fprintf(fid, '#DaVis 8.4.0 2D-vector 8 92 112 "position" "mm" "position" "mm" "velocity" "m/s" \n');
fclose(fid);
end
for k = 1:1:100
UFF = X_filter(1:ni*nk,k);
VFF = X_filter(1+ni*nk:2*ni*nk,k);
UFF1 =reshape (UFF,ni,nk)';
VFF1 =reshape (VFF,ni,nk)';
UUFFF1 = reshape (UFF1, 10304,1);
VVFFF1 = reshape (VFF1,10304,1);
xxx = reshape (X,10304,1);
yyy = reshape (Y,10304,1);
fileName = sprintf('test%d.txt',k);
dlmwrite(fileName,[xxx yyy UUFFF1 VVFFF1],'delimiter','\t','-append');
end

[KSSV]

Thanks is accepting the answer.. :)