Dear all, I have a dataset with hundreds of columns, I am only providing only 12 columns. Is it possible to take the mean of every four (or 12) columns (value601, value602, value603, value604 etc.in this case) and repeat for the hundreds of columns? Thank you.
Sincerely, Milu structure(list(value601 = c(10.1738710403442, 3.54112911224365, 12.9192342758179, 3.17447590827942, 11.7332258224487, 7.68282270431519, -7.11564493179321, 0.987620949745178, 13.0476207733154, 6.36939525604248 ), value602 = c(13.0642414093018, 5.53129482269287, 16.0519638061523, 2.88946437835693, 14.9204912185669, 9.42428588867188, -6.80674123764038, -0.614241063594818, 16.7947769165039, 7.9541072845459), value603 = c(22.0399188995361, 14.398024559021, 24.9523792266846, 12.0878629684448, 23.6459674835205, 18.3277816772461, -2.54092741012573, 10.5550804138184, 25.1016540527344, 16.2166938781738), value604 = c(27.7165412902832, 20.3255825042725, 30.8430004119873, 16.6856250762939, 29.2485408782959, 24.3775005340576, 6.47758340835571, 15.5897912979126, 30.7387924194336, 22.3637084960938 ), value605 = c(31.6644763946533, 23.4093952178955, 35.1488723754883, 19.7132263183594, 33.3924179077148, 29.5846366882324, 10.2083873748779, 19.3551616668701, 35.3076629638672, 27.4299201965332), value606 = c(33.9698333740234, 26.8574161529541, 36.8900833129883, 22.8604583740234, 34.8642921447754, 33.8158760070801, 14.7055835723877, 22.1144580841064, 37.0545425415039, 32.1087913513184), value607 = c(36.0279846191406, 26.9297180175781, 38.2701225280762, 23.2643146514893, 36.7398796081543, 34.1216125488281, 17.1387901306152, 24.0419750213623, 37.8542327880859, 32.7677421569824 ), value608 = c(34.0242347717285, 25.7720966339111, 36.4897193908691, 22.0332260131836, 34.8011703491211, 32.6856842041016, 16.6232261657715, 21.5571365356445, 36.1491546630859, 31.1716938018799), value609 = c(27.5402088165283, 21.7590408325195, 30.5214176177979, 18.4252090454102, 29.1156253814697, 26.9878330230713, 12.4962501525879, 17.7259578704834, 30.9099159240723, 25.4832077026367), value610 = c(23.4706859588623, 17.0126209259033, 26.8166942596436, 15.297459602356, 25.1733055114746, 23.5616931915283, 8.86995983123779, 13.5793552398682, 27.5732250213623, 22.1691932678223 ), value611 = c(14.5820417404175, 9.08279132843018, 17.8419170379639, 8.36016654968262, 16.5633754730225, 14.8123331069946, 1.32095837593079, 5.73408317565918, 18.9752082824707, 13.5729999542236), value612 = c(9.12979793548584, 2.79943537712097, 11.6504030227661, 2.21584677696228, 10.5404834747314, 7.55471754074097, -5.58141136169434, -0.566209673881531, 12.3264112472534, 6.65576601028442)), .Names = c("value601", "value602", "value603", "value604", "value605", "value606", "value607", "value608", "value609", "value610", "value611", "value612"), row.names = c("1", "2", "3", "4", "5", "6", "7", "8", "9", "10"), class = "data.frame") [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.