Concise way to print vectors/matrices of unequal length to .txt file - MATLAB

Question

I have three matrices A B C containing numerical data and which are of unequal lengths (e.g. A=88x1, B=121x1, C=240x1 - lengths are variable between data sets). In order to print these to a .txt file without padarray and to fill in the unequal lengths with white space instead, i've been using:

con = [{A} {B} {C}];
lens = cellfun('length',con);
max_length = max(lens);
con_reg = cell(max_length,numel(lens));
con_reg(:) = {''};
con_reg(bsxfun(@le,[1:max_length]',lens)) = cellstr(num2str(vertcat(con{:})));
wspace = repmat({char(9)},max_length,1);
out_str = [];
for iter = 1:numel(con)
    out_str = [out_str char(con_reg(:,iter)) char(wspace)];
end
out_cell = cellstr(out_str);
ext = '.txt';
filename = strcat((genotype{1}),'-',num2str(threshold),'bpThresh',ext);
fid1 = fopen(filename{1},'wt');
for row = 1:numel(out_cell)
    fprintf(fid1,'%s\n',out_cell{row});
end
fclose(fid1);
toc

However this feels quite convoluted and difficult to read.

Is there a more concise, simpler way to accomplish this?

Secondly, one feature I particularly like about writetable is the ability to include column headers. How could I incorporate this into a solution? writetable itself seems to explicitly require vectors of equal length and thus padding. I'm working on OS X so using xlswrite is not much of a viable option.

EDIT:

I've reduced down the necessary code by making use of tables and writetable:

con = [{A} {B} {C}];
lens = cellfun('length',con);
max_length = max(lens);
con_reg = cell(max_length,numel(lens));
con_reg(:) = {''};
con_reg(bsxfun(@le,[1:max_length]',lens)) = cellstr(num2str(vertcat(con{:})));
T = cell2table(con_reg);
ext = '.txt';
filename = strcat((genotype{1}),'-',num2str(threshold),'bpThresh',ext);
writetable(T,filename{1},'Delimiter','\t');

Interested if there are any more improvements that can be made.

what about save as *.csv using "csvwrite"? (de.mathworks.com/help/matlab/ref/csvwrite.html) — Lati
Can csvwrite write multiple matrices? It appears to only be able to write a single, combined matrix. — AnnaSchumann
csvwrite works only with one matrix but there are other ways to create csv files. Check my answer below. (Ps: I can't mention your name in the comment don't know why) — Lati

Lati Lati · Accepted Answer · 2015-08-09T18:02:30

Modified your code little bit to write as csv:

con = [{A} {B} {C}];
lens = cellfun('length',con);
max_length = max(lens);
con_reg = cell(max_length,numel(lens));
con_reg(:) = {''};
con_reg(bsxfun(@le,[1:max_length]',lens)) = cellstr(num2str(vertcat(con{:})));
% insert commas between the columns instead
wspace = repmat(',',max_length,1);
out_str = [];
for iter = 1:numel(con)
    out_str = [out_str char(con_reg(:,iter)) char(wspace)];
end
out_cell = cellstr(out_str);
% extension will be csv
ext = '.csv';

filename = strcat((genotype{1}),'-',num2str(threshold),'bpThresh',ext);

fid1 = fopen(filename,'wt');

for row = 1:numel(out_cell)
    fprintf(fid1,'%s\n',out_cell{row});
end
fclose(fid1);

Concise way to print vectors/matrices of unequal length to .txt file - MATLAB

1 Answers