Get variable name into filename using strcat

I am trying to create a filename for a .csv file using an existing variable name, which is a number e.g. '5100', and a manual input, e.g. 'files'.

My code:

x=sum(A(:,2:end),2); %column vector containing the sum of each row (from columns 2:end)

short_files=A(find(x==0),1); %get datenum corresponding to each row of zeros

formatOut='yymmddHHMMSS'; %convert datenum back to original filename format
short_files=datestr(short_files, formatOut);  

filename_shortfiles=('short_files.csv'); %.csv filename

serialNo='5100';
%try to get serial no into filename :-S
%filename_shortfiles=strcat(serialNo,'short_files.csv'); %.csv filename

dlmwrite(fullfile(path,filename_shortfiles),short_files,'delimiter',''); 

Here, A is a matrix of data. Within that, I find the rows that contain zeros, and take the value in the first column of those particular rows. It is these values which I put in my output file that I am trying to write to a .csv file.

If I try

filename_shortfiles=('short_files.csv'); 

...this works, but I would like to have part of the filename change on each iteration of the loop, depending on the value of serialNo.

The value of serialNo changes on each iteration of an earlier part of my code...

serialNo is a 1x1 double, is this the problem? I tried converting it using char() but this didn't work.

Thanks!

[Stephen23]

Do NOT use path as a variable name, as this shadows the very important inbuilt path function.

[Louise Wilson]

Thank you Stephen, that makes sense. Can you please point to where I am doing this? I'm confused because I think I only use path here:

dlmwrite(fullfile(path,filename_shortfiles),short_files,'delimiter',''); 

and this is using the path to the folder where I want to write the files?

[Walter Roberson]

The problem is in naming your variable "path" . Name your variable something else.

If you are trying to refer to the current directory, then you should use cd()

Answer 1

[Stephen23]

Nowhere do you describe/show what the output filename should look like, but this should get you started:

>> sno = 5100;
>> inp = 'short_files.csv';
>> [~,fnm,ext] = fileparts(inp);
>> out = sprintf('%s_%d%s',fnm,sno,ext)
out = short_files_5100.csv