OK, I am still getting the hang of MATLAB. I have two files in different format. One Excel file. data1.xls, size= 86400 X 62. It looks like:

Date/Time par1 par2 par3 par4 par5 par6 par6 par7 par8 par9
08/02/09 00:06:45 0 3 27 9.9 -133.2 0 0 0 1 0

Another file, data2.csv, size = 144 X 27. (If nothing is missing.)

It looks like:

date time  P01 P02 P03 P04 P05  P06  P07 P08 P09  P10  P11
8/16/2009 0:00  51   45  46    54   53  52 524  5  399      89      78

Now I am using

Data10minAvg = mean(reshape(Data,300,144,62));

to get the 10 min average of the first Excel file. Now I need to match up that file I am making above with the .csv file. The problem is many timestamps are missing in the .csv file.

How do I make data2.csv into a file of size 144 X 27, replacing the missing datestamps by rows of zero?

It will really help me than compare data1.xls file with newdata2.csv.