How can I create a cell array whose cells are strings based on a sequence of integers 1:N (for any N)?

I want my function to add a legend to a plot where the legend has a variable number of items depending on N: e.g. '1', '2', '3' if N=3. The help file tells me I can use a matrix or a cell array: legend(M). But I can't find a way of creating a suitable array without fixing the number of cells. For example,

num2cell(1:N)'

doesn't help because legend() only seems to accept cell arrays containing strings, not numeric values. And int2str() doesn't help because it adds spaces in between the numbers.

Answer 1

[Stephen23]

This works for any MATLAB versions:

>> arrayfun(@num2str,1:3,'Uni',0)
ans = 
    '1'    '2'    '3'

Answer 2

[Andrei Bobrov]

cellstr(string(1:3))

[Guillaume]

or

cellstr(compose('%d', 1:3))

if you want more control over the formatting.

[Richard Gunton]

Neither of these works in my MATLAB installation (7.9.0)...

Answer 3

[Jan]

C = sprintfc('%d', 1:3)

This is not documented, but exists for many years now.

[Stephen23]

http://undocumentedmatlab.com/blog/sprintfc-undocumented-helper-function

Yes... very nice, but sadly undocumented. Has anyone put in a feature request?

[Guillaume]

As of the introduction of compose (R2016b), sprintfc is no longer needed.

[Stephen23]

@Guillaume: I am not totally convinced about that. The main advantage of sprintfc is speed: it really is very fast. And given the significantly larger memory requirements of strings compared to simple numeric/char arrays, I think some performance comparisons are required before declaring sprintfc to be superfluous.

https://www.mathworks.com/matlabcentral/answers/335924-can-t-declare-strings-doublequotes-are-invalid-characters#answer_263437

[Andrei Bobrov]

+1