construc a string from other strings and variables

I am just trying to construct a single string to use as a file name, from several other strings and variables. Should be simple, but I cannot get the syntax right. For example:

subj = 'A2';
ndip = '2503';
nroi = '68';
band = '2-4';
fil_nam = [subj '_b' band '_d' ndip '_s' nroi];

fil_nam is created as a cell array, so how do I force it to be a string? Or convert to string?

Thanks

[Walter Roberson]

Please re-check your actual code to see if you possibly used {} instead of [] ?

Answer 1

[Azzi Abdelmalek]

If fil_nam is a cell array

fil_nam = {subj '_b' band '_d' ndip '_s' nroi}
out=strjoin(fil_nam)

[Walter Roberson]

strjoin() puts a space between the parts by default. You can specify '' as the delimiter to avoid the space. If you are going to do that then you might as well use

out = cat(2, fil_name{:});

[Azzi Abdelmalek]

Exact, or we can use

out=[fil_nam{:}]

Answer 2

[per isakson]

I find sprintf to be the best function to combine fixed strings and values of string (and numeric) variables into one string. Thus,

    sprintf( '%s_b%s_d%s_s%s', subj, band, ndip, nroi )

returns

    ans =
    A2_b2-4_d2503_s68