how to make hourly average

I have data in excel file The first column is date with format 1/01/2005 1:00 until 1/01/10 0:00 including 366 days on leap year. The second column is gas demand in cubic meters. What I want to ask are: 1. How to make average for each hour for every for month? (x=00.00-23.00; y= gas demand; curve = jan-april, may-august, and sept-dec). 2. How to make average for each day on the week?(x=Monday, Tuesday, Wednesday, ... Sunday; y=gas demand). Any help is appreciated. Thank you

[Jan]

Is this really an Excel file and do you want to perform the calculations in Matlab? Is "1/01/2005 1:00" a text string inside an CSV-file or the rqw data replied as 3rd output from XLSREAD? Did you import the file already?

Answer 1

[Andrei Bobrov]

h0 = cumsum(ones((datenum(2010, 1, 1)-datenum(2005, 1, 1))*24,1));
d0 = datenum(2005,1,1,h0,0,0);  % Let your date
d2 = datevec(d0);
data = randi(125,numel(d0),1);  % Let your data

[~,iI1] = histc(d2(:,2),[1 5 9 inf]);
valueI = accumarray([d2(:,4)+1, iI1],data,[],@mean); % first part of your question

iII = weekday(d0);
xII = mod(iII - 2,7)+1;
valueII = accumarray(xII,data,[],@mean); % second part of your question