MATLAB: Read and write text to matrix and write to Excel

excelexporting to excelimporting excel datanantext;writing to excelxlsreadxlswrite

Hello. Here's what I am trying to do.
1. Read in data from a sheet called 'StimuliInExcel' in an Excel spreadsheet. Rows 1, 6, 7, and 8 are numbers, row 2 is blank, and rows 3, 4, and 5 are text. Assign it to Matrix.
2. Randomly shuffle the rows.
3. Go through each line. If it is an even-numbered row, print 'PalmerTrialProc' in Matrix(i,4). If it is an odd-numbered line, print 'WilliamsTrialProc' in Matrix(i,4).
4. Write this new information to a sheet in the Excel document called 'UpdatedList'.
It is not printing 'PalmerTrialProc' or 'WilliamsTrialProc' in Matrix(i,4) as it iterates through the loop. I am not sure how to make it do that. Here is my current code:
 Matrix=xlsread('StimuliInExcel.xlsx', 'CompleteList')
 Matrix=Matrix(randperm(124),:) 
 Matrix
 for i = 1:124
    if mod(i,2)==0
        Matrix(i,4)=fprintf('%s','PalmerTrialProc')
    else
        Matrix(i,4)=fprintf('%s','WilliamsTrialProc')
    end
end
 xlswrite('StimuliInExcel.xlsx',Matrix,'UpdatedList')
I think this issue has something to do with NaN appearing in my Matrix.
Is there a way to write text to these NaN cells? Is the issue with how they are read?
If I type Matrix(i,4)='PalmerTrialProc' in the IF statement like so:
 Matrix=xlsread('StimuliInExcel.xlsx', 'CompleteList')
Matrix=Matrix(randperm(124),:) 
Matrix
 for i = 1:124
    if mod(i,2)==0
        Matrix(i,4)='PalmerTrialProc'
    else
        Matrix(i,4)='WilliamsTrialProc'
    end
end
 xlswrite('StimuliInExcel.xlsx',Matrix,'UpdatedList')
Then I get this message:
 Assignment has more non-singleton rhs dimensions than non-singleton subscripts
If I type this:
 Matrix=xlsread('StimuliInExcel.xlsx', 'CompleteList')
 Matrix=Matrix(randperm(124),:) 
 Matrix
 for i = 1:124
    if mod(i,2)==0
        xlswrite('StimuliInExcel.xlsx',Matrix(i,4),'PalmerProc','UpdatedList')
    else
        xlswrite('StimuliInExcel.xlsx',Matrix(i,4), 'WilliamsProc','UpdatedList')
    end
end
 xlswrite('StimuliInExcel.xlsx',Matrix,'UpdatedList')
I get the following error, which I think means I need to consider how I convert i to a corresponding letter of the alphabet, but I'd rather not go down that road:
 The specified data range is invalid or too large to write to the specified file format. Try writing to an XLSX file and use Excel A1 notation for the range argument, for example, ‘A1:D4’.
Thank you for any help you can provide.

Best Answer

You are passing the constant string 'UpdatedList' in the position where an Excel range would need to go.
When you use
   Matrix=xlsread('StimuliInExcel.xlsx', 'CompleteList')
then the output in Matrix is going to be only numeric, and any all-text headers or all-text leading columns would be removed.
In your loop you do
Matrix(i,4)=fprintf('%s','PalmerTrialProc')
The output of fprintf() is the count of the number of characters that were produced and displayed. You are then putting that (numeric) count into Matrix.
"Go through each line. If it is an even-numbered row, print 'PalmerTrialProc' in Matrix(i,4). If it is an odd-numbered line, print 'WilliamsTrialProc' in Matrix(i,4)."
That would require that you convert Matrix into a cell array.
What you should probably be doing is using
     [~, ~, Matrix] = xlsread('StimuliInExcel.xlsx', 'CompleteList')
and then working with the "raw" data in Matrix, which will be a cell array with a mix of strings and numeric values.
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