How to fprintf one large variable that is a table?

I have a variable "fluence_rate" in my workspace that is a 24056x2000 table. How do I frpintf this and have it perfectly aligned column by column instead of one extremely long column? Also is it normal if it takes a really long time?

Answer 1

[dpb]

nCol=10;                                    % how many columns you want???
fmt=[repmat('%11.3E',1,nCol) '.\n'];        % format string for that many
fprintf(fid,fmt,X.');                       % print array, note transpose

Adjust the column and format to suit

[HC]

I don't find this answer to be very clear.

[dpb]

1. Define the number columns you want in the output file (nCol)
2. Create format string of that many fields and newline after
3. Print the array (variable "X" here, use your desired array name)

That leaves only deciding what actual format you want the values printed at to set the specific field form, the '%11.3E' here, see the documentation for fprintf for details on format strings.

And, of course, there are several examples at

doc fprintf

and remember must get the file handle fid via fopen and then to fclose(fid) when finished.

[djk]

Thank you DB! I used your solution to print arrays with variable column numbers to a file. I found a typo, though -

fprintf(fid,X.')

should be

fprintf(fid,fmt,X.')

Thank you again.

[dpb]

Indeed, good catch...I'll fix the original to reflect.

BTW, NOTA BENE that normally the nCol would be size(x,2), the number of columns in the array itself -- but the Q? here with an array of 2000 seemed like might want to cut that down -- although if each column really were a variable, then it might still be the right thing to do, just that printing such a large array in human-readable text format is the questionable decision.