Running the Same code for Multiple Files in a Folder

Hi,

tt10001 = readtable('10001.xlsx');
dsa = tt10001;  
modelspec = 'Street ~ Catch*BackUp*PRCP - Catch:BackUp:Break:Manhole:PRCP';
mdl10001 = fitglm(dsa,modelspec,'Distribution','poisson')

I have multiple excel files (almost 200), such as "10001.xlsx" in a folder. The spreadsheets are of various zip codes, such as "10002.xlsx", "10003.xlsx"...

How can I run this code for every file in the folder?

And have the results "mdl10001.CoefficientCovariance" of each file exported to its own Excel spreadsheet, as in xlswrite?

Thanks. I'd very much appreciate any help with this.

Answer 1

[Walter Roberson]

indir = '.';            %path to input directory
outdir = 'results';     %path to where to put the results
if ~exist(outdir, 'dir'); mkdir(outdir); end

dinfo = dir(fullfile(indir, '*.xlsx'));
filenames = 
nfiles = length(filenames);

for K = 1 : nfiles
    thisfile = filenames{K};
    infile = fullfile(indir, thisfile);
    outfile = fullfile(outdir, thisfile);
    tt10001 = readtable(infile);
    dsa = tt10001;  
    modelspec = 'Street ~ Catch*BackUp*PRCP - Catch:BackUp:Break:Manhole:PRCP';
    mdl10001 = fitglm(dsa, modelspec, 'Distribution', 'poisson');
    outdata = mdl10001.CoefficientCovariance;
    writematrix(outdata, outfile);       %needs R2019b or later
end

If you are using earlier than R2019b then the last few lines would be

   outdata = mdl10001(:,'CoefficientCovariance');   %the sub-table!
   writetable(outdata, outfile);

[CMatlabWold]

Thank you! What do I put for line5 filenames =

[CMatlabWold]

I tried filenames = {dinfo(:).name}.'

But, its now working. Its only reading the first column of the worksheet, which is "BackUp"

And, the columns are the following:

BackUp Catch Manhole PRCP Street

I have Matlab 2018a, but

outdata = mdl10001(:,'CoefficientCovariance'); %the sub-table!

writetable(outdata, outfile);

gives me an error response:

Error in writetable (line 124)

write(a,filename,varargin{:})

[Walter Roberson]

Sorry, I amn not sure what happened there,

filenames = {dinfo.name};

Can you attach a sample .xlsx for testing?

[CMatlabWold]

Sure. Thanks. I've attached sample 4 spreadsheets. I am supposed to run the code for each zip code in NYC, individually. In my folder, I have 195 zip codes (195 spreadsheets).

[Walter Roberson]

10004.xlsx fails because it does not contain a column for "Break"

[CMatlabWold]

It works perfectly. Thank you!