How can I use fprintf to print an mxn matrix of values to a file

I have a calculated flow net of values in a matrix that I want to print in order (mxn)

How can I print the matrix to a file that has the matrix (rows x cols) in order. How would I do this using fprintf since I don't see any way to repeat using this function.

Answer 1

[Star Strider]

There are a numberr of ways to write your matrix, depending on what you want to do.

Since you want to use fprintf, if ‘M’ is your matrix:

fid = fopen( ... , 'wt')
fprintf(fid, [repmat('%10.5f\t', 1, size(M,2)) '\n'], M')                   % Note Transpose Operation
fclose(fid);

That should work. Experiment to get the result you want.

[Walter Roberson]

Pay attention to the ' after the M at the end of the second line: it is important to get this to work.

Personally I would use .' instead of ' since ' by itself is conjugate transpose. There would be no difference to the output as fprintf() always ignores the imaginary part of values anyhow, but ' is unnecessary work compared to .' IMHO.

[Thomas Burbey]

Thank you. It works!

[Star Strider]

As always, my pleasure!

[tbaracu]

If I want to print a matrix M = [1 5 6.8 ; 2 9 13 ; 68 11 ], how I will complete fprintf ?

I got finally fprintf([repmat('%10d\t', 1, size(M,2)) '\n'], M'). But still I have a question for a more complex case presented in the next message.

[tbaracu]

How I can print a group like this:

i x[i] DivDiff

--------------------------------

0 1 5 2 1

1 2 7 5

2 4 17

In which: i = 0, 1, 2 ; x = 1 , 2, 4 and DivDiff is matrix like this (empty spaces could be considered 0 or NaN):

5 2 1

7 5

17

[Star Strider]

tbaracu — Post this as a new Question.

Answer 2

[Minkang Cheng]

Hello

I did [U,S,V]=svd(A)

The S is diagonal matrix of singular values with size oof mxn, then, I use fprintf to print S in a file as

fprintf(fid, [repmat('%10.5f\t', 1, size(S,2)) '\n'], S]

This statement works for U with size of mxm, and V with size of nxn

the result is mxn for S, but the singular values are not in diagonal. Somthing wrong for fprinf or svd function?

Thanks

MK