Matlab printmat

Question

I am new to Matlab. Is there a way to use printmat to print 2 words heading?

Example result as followed:

 Title One        Title Two             


        

Answer 1

Well, the documentation of printmat tells you that

PRINTMAT(A,NAME,RLAB,CLAB) prints the matrix A with the row labels RLAB and column labels CLAB. NAME is a string used to name the
matrix. RLAB and CLAB are string variables that contain the row
and column labels delimited by spaces.

So spaces in the title are not natively supported.

As a workaround, you can use another separator that "looks like a space", for example, the unit separator:

printmat (
    matA, '', 'one two', ...
    ['Title' char(31) 'One Title' char(31) 'Two Title' char(31) 'Three']);

output:

Test = 
           Title One    Title Two  Title Three
    one     11.00000     22.00000     33.00000
    two     22.00000     33.00000     44.00000

But as you see, this gets awkward real fast. It will also probably not look right when printed to file or some other output than the Matlab command window (terminal, for instance). You'll have to experiment a bit.

Personally I would just write my own, more general pretty-printer using cells and sprintf with specific field-widths in the format string, as suggested by H.Muster (+1).

Answer 2

Another option is to redefine printmat as follows: What I've done is add a new parameter to the function called separator, and you can call the printmat_v2 function with the separator you want between titles. e.g:

 printmat_v2 (matA, ' ' , ' ' , 'Title OneL Title TwoL Title Three','L');

Code:

function [] = printmat_v2(a,name,rlab,clab,separator)
%PRINTMAT Print matrix with labels.
%
%   PRINTMAT(A,NAME,RLAB,CLAB) prints the matrix A with the row labels
%   RLAB and column labels CLAB.  NAME is a string used to name the 
%   matrix.  RLAB and CLAB are string variables that contain the row
%   and column labels delimited by spaces.  For example, the string
%
%       RLAB = 'alpha beta gamma';
%
%   defines 'alpha' as the label for the first row, 'beta' for the
%   second row and 'gamma' for the third row.  RLAB and CLAB must
%   contain the same number of space delimited labels as there are 
%   rows and columns respectively.
%
%   PRINTMAT(A,NAME) prints the matrix A with numerical row and column
%   labels.  PRINTMAT(A) prints the matrix A without a name.
%
%   See also: PRINTSYS.

%   Clay M. Thompson  9-24-90
%   Copyright (c) 1986-93 by the MathWorks, Inc.

error(nargchk(1,5,nargin));

[nrows,ncols] = size(a);

if nargin<2, name = []; end
if nargin==3, error('Wrong number of input arguments.'); end
if nargin<4,
  rlab = []; clab = [];
  for i=1:nrows, rlab = [rlab, '--',int2str(i),'--> ']; end
  for i=1:ncols, clab = [clab, '----',int2str(i),'---- ']; end
  rlab=rlab(1:length(rlab)-1);
  clab=clab(1:length(clab)-1);
end

col_per_scrn=5;
len=12;


if (nrows==0)|(ncols==0), 
  if ~isempty(name), disp(' '), disp([name,' = ']), end
  disp(' ')
  disp('     []')
  disp(' ')
  return
end

% Remove extra spaces (delimiters)
ndx1 = find(clab==separator);
ndx2 = find([ndx1,0]==[-1,ndx1+1]);
if ~isempty(clab), clab(ndx1(ndx2))=[]; end

ndx1 = find(rlab==' ');
ndx2 = find([ndx1,0]==[-1,ndx1+1]);
if ~isempty(rlab), rlab(ndx1(ndx2))=[]; end

% Determine position of delimiters
cpos = find(clab=='L');
if length(cpos)<ncols-1, error('Not enough column labels.'); end
cpos = [0,cpos,length(clab)+1];

rpos = find(rlab==' ');
if length(rpos)<nrows-1, error('Not enough row labels.'); end
rpos = [0,rpos,length(rlab)+1];

col=1;
n = min(col_per_scrn-1,ncols-1);
disp(' ')
if ~isempty(name), disp([name,' = ']), end  % Print name
while col<=ncols
  % Print labels
  s = ' '*ones(1,len+1);
  for j=0:n,
    lab = clab(cpos(col+j)+1:cpos(col+j+1)-1);
    if length(lab)>len,
      lab=lab(1:len);
    else
      lab=[' '*ones(1,len-length(lab)),lab]; end
    s= [s,' ',lab];
  end
  disp(s)
  for i=1:nrows,
    s = rlab(rpos(i)+1:rpos(i+1)-1); 
    if length(s)>len, s=s(1:len); else s=[' '*ones(1,len-length(s)),s]; end
    s = [' ',s];
    for j=0:n,
      element = a(i,col+j);
      if element==0,
        s=[s,'            0'];
      elseif (element>=1.e6)|(element<=-1.e5)|(abs(element)<.0001)
        s=[s,sprintf(' %12.5e',element)];
      else
        s=[s,sprintf(' %12.5f',element)];
      end
    end
    disp(s)
  end % for
  col = col+col_per_scrn;
  disp(' ')
  if (ncols-col<n), n=ncols-col; end;
end % while

Answer 3

According to Matlabs help, printmat will not provide what you are seeking. You can use sprintf instead.

a = [ 11 22 33; 22 33 44];
s = {'Title One' 'Title Two' 'Title Three'};
s1 = sprintf('%12s\t%12s\t%12s\t\n', s{:});
s2 = sprintf('%12d\t%12d\t%12d\n', a);

horzcat(s1,s2)

This results in

ans =

   Title One       Title Two     Title Three    
          11              22              22
          33              33              44

~edit~
If the use of printmat is preferable (e.g., because it is more flexible) you can work around by using evalc and strrep. The trick here is to replace the spaces with other symbols (e.g. question marks) in the call to printmat, store the output in a string via evalc, and then use strrep to replace the question marks by spaces. As a nice byproduct, you get the table as a string...

a = [ 11 22 33; 22 33 44];
x = evalc('printmat(matA, '''' , ''a b c'' , ''Title?One Title?Two Title?Three'')');

s = strrep(x, '?', ' ')

This results in

s =


                 Title One    Title Two  Title Three
            a     11.00000     22.00000     33.00000
            b     22.00000     33.00000     44.00000

However, the combination of printmat and evalc causes a lot of apostrophes...