How to write output data in excel csv files?

My for loops are as follows;

number of image files are 114

number of shape files are 242

for m = 1:length(imgfiles)
    for n = 1:length(shapefiles)
        avg_village_ndvi(n,m) = mean(village_ndvi(mask));
        avge_village_ndre1(n,m) = mean(village_ndre1(mask));
        avg_village_cire(n,m) = mean(village_cire(mask));
        CAF(n,m) = nnz(village_ndvi(mask) > 0.4) / (size(village_ndvi,1)*size(village_ndvi,2))
    end
end

I want to write these data in seperate excel csv file with file name as 'c:\data\ndvi_predictors.csv','c:\data\ndre1_predictors.csv','c:\data\cire_predictors.csv' and 'c:\data\caf_predictors.csv'.

I request all to please suggest me how to do it in above mentioned matlab code.

I would appreciate any help in this regard.

Dave

Answer 1

[Voss]

After the for loops:

writematrix(avg_village_ndvi,'c:\data\ndvi_predictors.csv')
writematrix(avge_village_ndre1,'c:\data\ndre1_predictors.csv')
writematrix(avg_village_cire,'c:\data\cire_predictors.csv')
writematrix(CAF,'c:\data\caf_predictors.csv')

[Devendra]

Thank you so much for helping me out in writing output data into csv files. One more thing I want to add the first column as name of shape file followed by data in successive columns of each csv output file. How to do it please suggest me this also.

Once again thank you very much for your kind support.

Dave

[Voss]

You're welcome!

Here's how you can include the shape files' names as the first column:

names = cellstr(shapefiles(:));
writecell([names num2cell(avg_village_ndvi)],'c:\data\ndvi_predictors.csv');
writecell([names num2cell(avge_village_ndre1)],'c:\data\ndre1_predictors.csv');
writecell([names num2cell(avg_village_cire)],'c:\data\cire_predictors.csv');
writecell([names num2cell(CAF)],'c:\data\caf_predictors.csv');

If this answer solved the problem, please "Accept" it. Thanks!

[Devendra]

I am very grateful to you for helping me out. Just one more additional thing I want to add. suppose I want to extract date stamp from image file names and add to first row of each csv file. For example name of image file is as follows

20240314_MAWANA-SUBSET

I want to extract the date stamp as 20240314 from the first image file and so on. These date stamps I want to write in first row of each csv file. How to write these date stamps in first row of each csv file.

I really appreciate your kind cooperation.

Dave

[Voss]

[~,fn] = fileparts(imgfiles);
img_names = regexp(fn,'\d+','match','once');
img_names = cellstr(reshape(img_names,1,[]));

names = cellstr(shapefiles(:));

writecell([{''} img_names; names num2cell(avg_village_ndvi)],'c:\data\ndvi_predictors.csv');
writecell([{''} img_names; names num2cell(avge_village_ndre1)],'c:\data\ndre1_predictors.csv');
writecell([{''} img_names; names num2cell(avg_village_cire)],'c:\data\cire_predictors.csv');
writecell([{''} img_names; names num2cell(CAF)],'c:\data\caf_predictors.csv');

[Devendra]

Thank you very much for your kind help. I have encountered a small problem as follows

Error using fileparts (line 15)

Input must be a row vector of characters, or a string scalar, or a cellstr, or a string matrix.

Error in ds_indices_caf (line 91)

[~,fn] = fileparts(imgfiles);

Please suggest me how to fix it.

Deva

[Voss]

That error is due to imgfiles being of an unexpected class. What class is imgfiles? To find out, please put the following just before the fileparts line, and show its output:

class(imgfiles)

[Devendra]

class(imgfiles)

ans = 'struct'

Please have a look at it and suggest me to fix it.

deva

[Voss]

I assume imgfiles is the struct returned from a dir() call. In that case, change the fileparts line to:

fn = {imgfiles.name};

If shapefiles is also a struct returned by dir(), then you'll have to modify the line defining names as well:

names = {shapefiles.name}.';

[Devendra]

It worked successfully. I am very much thankful to you.

Deva

[Voss]

You're welcome! Glad to hear it worked!

[Devendra]

I want to write each line(row) two times in the following excel csv file. I request you to please suggest me how to do it in the following files

writecell([{''} img_names; names

num2cell(avg_village_ndvi)],'c:\data\ndvi_predictors.csv');

writecell([{''} img_names; names num2cell(avge_village_ndre1)],'c:\data\ndre1_predictors.csv');

writecell([{''} img_names; names num2cell(avg_village_cire)],'c:\data\cire_predictors.csv');

writecell([{''} img_names; names num2cell(CAF)],'c:\data\caf_predictors.csv');

Devendra

[Voss]

C = [{''} img_names; names num2cell(avg_village_ndvi)];
writecell(repelem(C,2,1),'c:\data\ndvi_predictors.csv');

C = [{''} img_names; names num2cell(avge_village_ndre1)];
writecell(repelem(C,2,1),'c:\data\ndre1_predictors.csv');

% and so on for the others

[Devendra]

Thanks for your kind help. It worked well.

Devendra

[Voss]

You're welcome!

[Devendra]

I want to use

fn = {imgfiles.name};

img_names = regexp(fn,'\d+','match','once');

img_names = cellstr(reshape(img_names,1,[]));

and want to extract the date stamp from the following file name

T43RGN_20210203T053029_B04_10m.jp2

as 20210203T053029

please suggest me how to get it using above mentioned lines.

Thanks for your kind help.

Devendra

[Voss]

img_names = regexp(fn,'_([\dT]+)_','tokens','once');
img_names = [img_names{:}];

[Devendra]

Thank you so much for your help. Devendra

[Voss]

You're welcome!