Hi Chris,
These are quite a bit faster in my experience, and testing with smaller example arrays, give a much better result.
I compare the two in the following code:
%% Using fprintf and fscanf, which seem order of magnitude faster
N=100; M=100;
x=rand(1,M);
dlmwrite('file',x,'delimiter',' ')
tic
fid = fopen('file.txt', 'a');
for k=1:N-1
x=rand(1,M);
%In the real application x is the result of some calculations
fprintf(fid,repmat('%f ', 1,M), x);
end
fclose(fid);
toc
tic
fid = fopen('file.txt', 'r');
for k=1:N
u=fscanf(fid,repmat('%f ', 1,M),[1 M]);
%calculations using vector u
end
fclose(fid);
toc
%% Using dlmwrite and dlmread
N=100; M=100;
x=rand(1,M);
dlmwrite('file',x,'delimiter',' ')
tic
for k=1:N-1
x=rand(1,M);
%In the real application x is the result of some calculations
dlmwrite('file',x,'delimiter',' ','-append')
end
toc
tic
for k=1:N
u=dlmread('file',' ',[k-1 0 k-1 M-1]);
%calculations using vector u
end
toc
You can test this with any data size you like, I suppose my computer is not nearly as fast as yours at the file processing.
The append feature of fprintf is particularly useful.
Hopefully that helps,
Michael
