Creating legend based on numeric array

I have a numeric array, for example:

N = [1 7 14 30 90 180 360];

I want to create a cell array for use in a figure legend:

legendCell = {'N=1','N=7',...,'N=360'}

This is trivial to do with a loop, and I can think of a couple ways that avoid loops that are a bit kludgy. What is the most elegant way?

[The "N=" part is fixed and known. It does not have to be the variable name.]

Answer 1

[Kelly Kearney]

One more:

 legendCell = cellstr(num2str(N', 'N=%-d'))

[Fangjun Jiang]

Never noticed num2str could also specify format. Nice! +1

[TheStranger]

But how one can insert a special tex-symbols like \omega and such in there? It throws an error.

[Fangjun Jiang]

use sprintf(), see special character section, get the unicode

Answer 2

[Steven Lord]

If you're using a newer release of MATLAB, I'd use a string array to create the legend.

N = [1 7 14 30 90 180 360];
x = linspace(0, 1, 17);
plot(x, N.*x.')

legendStrings = "N = " + string(N);
legend(legendStrings)

Answer 3

[Jan]

N = [1 7 14 30 90 180 360];
C = regexp(sprintf('N=%d#', N), '#', 'split');
C(end) = [];

Another solution: In older MATLAB versions DATAREAD (called as core function through STRREAD) was faster. But unfortunately these functions are deprecated. Now TEXTSCAN helps:

CC = textscan(sprintf('N=%d#', N), '%s', 'Delimiter', '#');
C = CC{1};

[Oleg Komarov]

regexp(sprintf('N=%d',N),'N=\d+','match')

Answer 4

[Paulo Silva]

My kludgy way:

legendCell = eval(['{' sprintf('''N=%d'' ',N) '}'])

[Fangjun Jiang]

Paulo, your first solution returns 1x1 cell

[Paulo Silva]

that's why I edited my question and removed it :)

[Fangjun Jiang]

I like the kludgy way. Seeing so many eval must have made a dent on your brain.

Answer 5

[Fangjun Jiang]

legendCell=strcat('N=',strtrim(cellstr(num2str(N'))))

Or better for N could be column vector or row vector

legendCell=strcat('N=',strtrim(cellstr(num2str(N(:)))))

Answer 6

[Oleg Komarov]

Hidden loop (troll):

arrayfun(@(x) sprintf('N=%d',x),N,'un',0)

Based on Kelly's idea of '%-d':

cellstr(reshape(sprintf('N=%-3d',N),floor(log10(abs(max(N))+1))+3,numel(N)).')

[Andrei Bobrov]

+1