MATLAB: Speed up the conversion of array of cells in numbers

cell arrayfor loopperformance

I have a problem regarding the use of a for loop. I would like to avoid this loop in order to have a faster execution of my code.
I have a vector of cells called str_cell. The length of the vector is NUM_LINES = 300. Each cell contains a string of 11 numbers in a string format, which are delimited by a TAB.
In the for loop I convert the cells in vectors of numbers and I pass them in an array, called data, which has been previously initialized.
Here the code
for i = 1:NUM_LINES
    numbers = str2double(strread(str_cell{i},'%s','delimiter','\t'));
    data(i, :) = numbers(:);
end
When NUM_LINES is 300, my computer takes ~290ms to do that. I tried to avoid the for loop, but the command str2double works with a single string so that I had to pass cell by cell. Moreover I cannot change the way to get the files, in order to by-pass the problem. Do you have suggestions about avoiding this for loop?
Thanks in advance

Best Answer

S = sprintf('%s ', str_cell{:});
D = transpose(sscanf(S, '%g', [11, inf]));
Speed measurement:
str_cell = cell(1, 300);
for is = 1:300; str_cell{is} = sprintf('%d\t', 1:11); end
tic;
S = sprintf('%s ', str_cell{:});
D = transpose(sscanf(S, '%g', [11, inf]));
toc
%                       0.004066 seconds  (R2009a/64, Win7, Core2Duo)
% Original loop:        0.130204 seconds.
% Azzi's STR2NUM(CHAR): 0.027707 seconds.
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