How to create a matrix from a txt file with variable column numbers?

Hey there!

I am trying to create a matrix from a txt file that the user inputs that goes like this:

Matrix

4

    1  1  3  2  6  1
    2  1  4  3  5  2  5
    3  1  3  4  8  3
    4  1  3  5  1  6

The number in the line after "Matrix" represents the number of lines of the matrix I wanna create.

The number of the 3rd column represent the remaining entries on that line and can only vary between 3 or 4.

I've come up with

tline = fgetl(file);
n = fscanf(file,'%f',1);
matrix = fscanf(file,'%e', [n inf]); % but this puts it into a 1x... Matrix...

Thanks for the help

[Jan]

What result do you want? A matrix is rectangular by definition.

[Diogo Nascimento]

I want to fill the shorter rows with zero, to make it rectangular

Answer 1

[Walter Roberson]

tline = fgetl(file);
n = fscanf(file, '%f', 1);
for K = 1 : n
   rownum = fscanf(file, '%f', 1);
   col_offset = fscanf(file, '%f', 1);
   num_ent = fscanf(file, '%f');
   data_for_row = fscanf(file, '%f', [1 num_ent]);
   data(rownum, col_offset + (0:num_ent-1)) = data_for_row;
 end

This will pad shorter rows with 0. I had to guess at the meaning of the fields.

[Diogo Nascimento]

This shows me this error:

   Error using horzcat
   Dimensions of matrices being concatenated are not consistent.
   Error in FileReader (line ...)
      data_for_row = fscanf(file, '%f', [1 num_ent]);

As you did, i want to put zero in the shorter lines

[Walter Roberson]

Change

     num_ent = fscanf(file, '%f');

to

     num_ent = fscanf(file, '%f', 1);

[Diogo Nascimento]

thank you so much! that did the trick!

just had to adjust

     data(rownum, col_offset + (0:num_ent-1)) = data_for_row;

to

      data(rownum, (1:num_ent)) = data_for_row;

and it worked for other matrixs!