how to append data to existing excel row

Hello,

I have an excel file with string already in it for the first 2 colums and I want to append numeric data after that but I'm having trouble trying to write to the correct row.

 Filename           Date of addition  Number of Cycles    Length
                #              (s) 
379Q1172e.v26  10/6/2011 10:58

Below is the code I have written

for i=1:length(cycle)
%extract excel data
      [xnum,xtxt,xraw] = xlsread(excel_file);
%find cycle length
      comp_cycle=(cycle(i,;2)-cycle(i,1))/100
%find correct cell position to write to
      posi = ['C',num2str(length(xraw(:,3)))];
      xlswrite(excel_file,{i,comp_cycle},'Data',posi);
end

The problem I'm having is when its read the excel file, the length of the column C returns 3, not 2, so it writes data to the row below it and not the same row as the filename.

Any idea how I can fix this?

Thanks!

[Fangjun Jiang]

Please re-examine your question. I don't think your mention of row and column is consistent with the data you show.

It might be that the third row of your Excel spreadsheet contains blanks. Check xraw to find it out.

[Max Bernstein]

Yeah you're right, there is a blank space and shows as []. Is there anyway to overwrite that blank space?

I tried to use posi = ['C',num2str(length(xraw(:,3))-1)];

but it overwrites C2, not C3.

[Fangjun Jiang]

It's easier if you clear your Excel file of those blank cells. Whatever trouble you have, you can put a break point in that line and debug your code. Check the value of posi and you'll know where it starts writing and whether that is what you are expecting.

Answer 1

[Laura Proctor]

Is it just a matter of subtracting one from the length to keep writing on the same row?

posi = ['C',num2str(length(xraw(:,3))-1)];

[Max Bernstein]

Yeah I tried that too but it wrote to row 2 like this (underscore is just blank space separating cells)

Filename_________Date of addition_____Number of Cycles_______Length

_______________________________________________1____________ 123

379Q1172e.v26_____10/6/2011 10:58

it overwrites the # and (s)