Dimensions of matrices being concatenated are not consistent - matlab

Question

i read a csv file with textscan and when i want write in a file i receive this error : Error using horzcat. Dimensions of matrices being concatenated are not consistent.
if i change the first format in textscan (i mean %S) to %f the error vanishes.
the error occurs when matlab want to make [datatest{1} probability]
probability is 1000*1 double
datatest{1} is 1000*1 cell
datatest=textscan(FileID,'%s %*f %f %f %*s %*s %*s %*s %*s %*s %*s %*s %*s %f %f %f %f %f %f %f %f %f %f',1000,'headerlines',1,'delimiter',',');
csvwrite('output.csv',[datatest{1} probability]);

Answer 1

Your variable datatest{1} contains 1000 cells which each contains a string (may be or may be not the same length).
In your statement [datatest{1} probability] you are trying to concatenate cells (containing strings) with double numeric type, this does not work. The concatenation operator needs to operate on data of similar type.
Now even if you were to create a cell array which would contain all your desired columns myCellArray={datatest{1} probability}, this would not help you because the output of that cannot be passed on the function csvwrite.
csvwrite, or the better sister dlmwrite, do not accept cell arrays. You would have to convert the cell values into numeric values. Unfortunately, you want to write strings and numeric values, so your only way is to use low level functions like fprintf
In your case, to write the file you were expecting, you can use the following code.
col1 = datatest{1} ; %// extract the column of interest for easier indexing later on
fidw = fopen('output.csv','w') ; %// get a handle on a file to write (necessary with "fprintf")
for iline = 1:numel(probability) %// loop on each line
fprintf( fidw , '%s, %f\n' , col1{iline} , probability(iline) ) ; %// write the line
end
fclose(fidw) ; %// close the file - IMPORTANT - (necessary with "fprintf")