How to get rid of this error when adding an element to the rows of a table?

I have a table with strings and double values. When I try to add new element in each row I will get this value. Could some one explain me what can be done?

Warning: The assignment added rows to the table, but did not assign values to all of the table's existing variables. Those variables have been extended with rows containing default values. > In tabular/subsasgnDot (line 338) In tabular/subsasgn (line 67) In orderMain (line 140)

[Guillaume]

Show us line 130 to 140 of orderMain.m.

The error is telling you that you're not giving enough values to fill all the column of your table when you add a row.

[Pratheek Manangi]

for i=1:length(rpmFixed)

    DatTab.rpm(i,1)=rpmFixed(i);
    DatTab.Lss1(i,1)=orderNewSlices{1,1}(1,i);
    DatTab.Lss2(i,1)=orderNewSlices{1,2}(1,i);
    DatTab.Lss3(i,1)=orderNewSlices{1,3}(1,i);
    DatTab.Lss4(i,1)=orderNewSlices{1,4}(1,i);
    DatTab.Lss5(i,1)=orderNewSlices{1,5}(1,i);
    DatTab.Lss6(i,1)=orderNewSlices{1,6}(1,i);
    DatTab.Lss7(i,1)=orderNewSlices{1,7}(1,i);
    DatTab.Lss8(i,1)=orderNewSlices{1,8}(1,i);
    DatTab.Lss9(i,1)=orderNewSlices{1,9}(1,i);
    DatTab.Lss10(i,1)=orderNewSlices{1,10}(1,i);
    DatTab.IMS1(i,1)=orderNewSlices{1,11}(1,i);
    DatTab.IMS2(i,1)=orderNewSlices{1,12}(1,i);
    DatTab.IMS3(i,1)=orderNewSlices{1,13}(1,i);
    DatTab.HSS1(i,1)=orderNewSlices{1,14}(1,i);
    DatTab.HSS2(i,1)=orderNewSlices{1,15}(1,i);
    DatTab.Hss3(i,1)=orderNewSlices{1,16}(1,i);

end

[Pratheek Manangi]

Hello Thanks for the reply,

Here is my code. Could you suggest me what I can do to resolve that warning?

Answer 1

[Guillaume]

You're probably using the slowest and most complicated way to create a table.

tempslices = cellfun(@ctranspose, orderNewSlices, 'UniformOutput', false);  %transpose the row vectors in the cell array to column vectors
DatTab = [table(rpmFixed(:), 'VariableNames', {'rpm'}), ...
          cell2table(orderNewSlices, 'VariableNames', ...
                     [compose('Lss%d', 1:10), compose('IMS%d', 1:3), compose('HSS%d', 1:3)])]

should do the same.

[Peter Perkins]

Yes, as Guillaume says, you don't want to be creating a table by looping and assigning one element at a time, while growing it row by row.

To answer your original question, for every loop iteration, this line

DatTab.rpm(i,1)=rpmFixed(i);

ads a new row and only assigns to one variable in that row. That's what the warning is telling you. It's usually a sign that you're doing something wrong.

At the very least, you could take all of those 17 assignments and create a 1x17 cell array, and assign that to a new row of the table. But as Guillaume correctly points out, you should need a loop at all.

[Pratheek Manangi]

Thanks a lot guys.

[Pratheek Manangi]

@Guillaume I was trying the code. It gives me an error. Could you please let me know what the error might be?

Error using cell2table (line 57) The VariableNames property must be a cell array, with each element containing one nonempty character vector.

Error in orderMain (line 190) cell2table(orderNewSlices, 'VariableNames', ...

[Guillaume]

You're probably using R2016b where compose returns string regardless of the input. In R2017a, with the syntax I used it returns a cell array of char. It's trivial to fix by converting the string array to cell array with cellstr:

DatTab = [table(rpmFixed(:), 'VariableNames', {'rpm'}), ...
        cell2table(tempslices, 'VariableNames', ...
                   cellstr([compose('Lss%d', 1:10), compose('IMS%d', 1:3), compose('HSS%d', 1:3)]))]

Note that I took a guess about the size and shape of your inputs. It's entirely possible that I got these wrong and as a result the above code will give an error, but the idea is there: convert your inputs into a table with the table creation functions , table, array2table or cell2table.

edit: Actually the above is probably not going to produce the right result due to the construction of your cell array. This may work better:

tempslices = cellfun(@ctranspose, orderNewSlices, 'UniformOutput', false);  
DatTab = table(rpmFixed(:), tempslices(:), 'VariableNames', ...
               ['rpm', cellstr([compose('Lss%d', 1:10), compose('IMS%d', 1:3), compose('HSS%d', 1:3)])])

[Pratheek Manangi]

I have same number of rows in rpmFixed and each cells in orderNewSlices. Yet I am getting this error message.

All variables must have the same number of rows.

[Guillaume]

Try

tempslices = cellfun(@ctranspose, orderNewSlices, 'UniformOutput', false);  
DatTab = table(rpmFixed(:), tempslices{:}, 'VariableNames', ...
               ['rpm', cellstr([compose('Lss%d', 1:10), compose('IMS%d', 1:3), compose('HSS%d', 1:3)])])

As I said, I'm just guessing at what would work since I don't have your data. You should be able to work out the exact syntax required from the above.

[Pratheek Manangi]

The problem is rpmFixed is 102*1 double and tempslices is 1*16 cell array which contains 102*1 doubles. when it reads it says variable must have same numbers. Basically i feel it compares 102*1 with 1*16.

[Guillaume]

Yes, note that my latest code differs from the earlier one where I'd made a mistake. I've changed tempslices(:) to tempslices{:} (notice the different brackets), which properly passes the elements of the cell array as columns.

If that still doesn't work then check the output of:

size(rpmFixed)
%and
celldisp(cellfun(@size, tempslices, 'UniformOutput', false))

[Pratheek Manangi]

Thanks a lot It did work