MATLAB: `WriteMode` isn’t working while appending data to xlsx

excelMATLABwritematrix

I'm doing the following


excelFilename = 'someFile.xlsx';
structFieldnames = fieldnames(myStruct); % <--- where myStruct is your struct of data
for k = 1:length(structFieldnames)
    fieldname = structFieldnames{k};
    writecell(myheaderstruct.(fieldname), excelFilename, 'Sheet', sprintf('%s_matlab', fieldname)); % add header
    writematrix(myStruct.(fieldname), excelFilename, 'Sheet', sprintf('%s_matlab', fieldname),'WriteMode','append');
end

Error:

Invalid parameter name: WriteMode.

If 'WriteMode','append' isn't included, the header is overwritten.

Could someone suggest why `WriteMode` isn't working here?

This is a follow up to my previous post here.

This

writematrix(data.(fieldname), excelFilename,'-append', 'Sheet', sprintf('%s_simgraph', fieldname));

also doesn't work.

Wrong number of arguments. A filename must be provided when supplying additional parameters, and each parameter name must be followed by a value.

I'm using 2109b.

Best Answer

https://www.mathworks.com/help/matlab/release-notes.html?rntext=&startrelease=R2020a&endrelease=R2020a&groupby=release&sortby=descending&searchHighlight=

Writemode is a new option as of R2020a.

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MATLAB: Working with structs & excel spreadsheets

You need to call xlsread at each iteration in order to read a new sheets.

XlsFile = 'YourXlsFile.xlsx';
% get the name of all your spreadsheets
[type, sheetname] = xlsfinfo(XlsFile);
% loop for each sheet
for i = 1:length(sheetname)
    MyData{i} = xlsread(XlsFile,sheetname{i});
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just adapat this piece of code to your problem.

Instead of

MyData{i} = xlsread(XlsFile,sheet{i});

just put something like

MyData{i} = YourImportdataScript(XlsFile,sheet{i});

MATLAB: Append character array to first row of a matrix

Astruct = struct('data1', randi(9,10,5), 'data2', randi(9,10,5))
data1_header = [1,3,2,4,5];
data2_header = [1,2,3,4,10];
C =  [ cellstr([ "col" + data1_header, "col" + data2_header])
      table2cell(splitvars(struct2table(V))) ];
writecell(C, excelFilename)

This assumes that you want them to go onto the same sheet. If you want different sheets then

Astruct = struct('data1', randi(9,10,5), 'data2', randi(9,10,5));
data1_header = [1,3,2,4,5];
data2_header = [1,2,3,4,10];
data_headers = {data1_header, data2_header};
data_contents = structfun(@(M) {num2cell(M)}, Astruct);
F = fieldnames(Astruct);
for K = 1 : length(F)
    C = [ cellstr("col" + data_headers{K});
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end

I tested, and this does create multiple sheets in the file.

What it will not do is put the data on the bottom of any existing sheet with the same name. If you want that, then you need to readcell() the existing sheet, append that at the top, and write the combination. Watch out for the possibility that the number of columns is different between the existing data and the new data.

Best Answer

Related Solutions

MATLAB: Working with structs & excel spreadsheets

MATLAB: Append character array to first row of a matrix

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