Dear All, I would like to ask you how to accomplish a little tricky data manipulation. I have a large dataset, looking something like:
temp line cage number 18 18 1 6678.63 18 18 1 7774.458 18 18 1 7845.902 18 18 1 9483.578 18 18 1 8983.555 18 18 1 9181.052 18 18 1 9458.696 18 18 1 8138.616 18 18 1 7981.994 18 18 1 7556.491 18 18 1 7672.137 18 18 1 6607.776 18 18 1 8383.65 18 18 1 7129.852 18 18 1 8536.667 18 18 2 8287.8 18 18 2 7924.47 18 18 2 7928.474 18 18 2 7363.157 18 18 2 7952.593 ..... I would like to create a dataframe where I get the mean values, 5 rows at a time, of columns "number", while keeping the value in the other columns fixed to the vaules found in the first of the 5 rows (or whatever, it's the same for the 5 rows) so that the above would be "shrunk" to: temp line cage number 18 18 1 8153.2246 18 18 1 8463.3698 18 18 1 7666.0164 18 18 2 7891.2988 Any hints? Regards, Federico Calboli ========================= Federico C.F. Calboli Department of Biology University College London Room 327 Darwin Building Gower Street London WClE 6BT Tel: (+44) 020 7679 4395 Fax (+44) 020 7679 7096 [EMAIL PROTECTED] ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help