How to replace all the ones in a matrix with the string 'hey'?

matrix= [1 0 0.1 0.001 4; 5.9 2.1 3.15 8.95 1.11]

All the ones should be replaced with 'hey'

This is my code

matrix= [1 0 0.1 0.001 4; 5.9 2.1 3.15 8.95 1.11];

matrix= num2str(matrix);

matrix(matrix=='1') = 'h'

when I replace 'h' with 'hey' it gives me this error

 matrix(matrix=='1') = 'hey'

I have just started to learn MATLAB. please help

Answer 1

[Walter Roberson]

newmatrix = num2cell(matrix);
newmatrix(matrix == 1) = {'hey'};

[oshawcole]

I want to replace all the ones, so 0.001 should look as 0.00hey. 1.11 should be hey.heyhey

[Walter Roberson]

newmatrix = char( regexp( cellstr(num2str(matrix)), '1', 'hey' ) )

(not tested)

[oshawcole]

Error using regexp Invalid option for regexp: hey.

[Walter Roberson]

newmatrix = char( regexprep( cellstr(num2str(matrix)), '1', 'hey' ) )

(Still not tested. My system is running a large program at the moment.)

[oshawcole]

matrix= [1 0 -1 0.001 4; 5.9 -1 3.15 1 1.11]

How can I replace the +1 and -1 with 'hey'? The answer should look like:

matrix= [hey 0 hey 0.001 4; 5.9 hey 3.15 hey 1.11]

[Walter Roberson]

newmatrix = regexprep( mat2str(matrix), {'\[', '\]', '(?<=\s|^)-?1(?=\s|$)'}, {'', '', 'hey'}, 'lineanchors')

[oshawcole]

is there a way to get it displayed as a matrix?

matrix= [1 0 -1 0.001 4; 5.9 -1 3.15 1 1.11 ];

cell_conv = (num2cell(matrix));

find_one = abs( matrix ) == 1 ;

cell_conv(find_one)={'hey'}

this is what I found? i just want to put this together in one line.

[Walter Roberson]

It is possible to do in one line, but it gets so messy that it is not recommended.

Here is a way to do it with the assistance of a helper function.

IDXAT = @(M,IDX) M(IDX);
disp(IDXAT(cat(3,num2cell(matrix),repmat({'hey'},size(matrix))), reshape(1:numel(matrix), size(matrix))+numel(matrix)*(abs(matrix)==1)))

The output would look like

    'hey'    [  0]    'hey'     [0.001]    [   4]
    [5.9]    'hey'    [3.15]    'hey'      [1.11]

I am not sure that is acceptable to you.

Answer 2

[John D'Errico]

You can't. A matrix is composed of numbers. You cannot insert a string for some elements, replacing an arbitrary numeric element.