[R] howto calculate column means in data frame

From: Maas James Dr (MED) <J.Maas_at_uea.ac.uk>
Date: Sun, 10 Apr 2011 16:27:33 +0100


Long story short, I have a big iterative procedure that produces a long list of data.frames such as the one called "results" here. Is there an easy way to produce a similar list of data.frames comprised of the mean of each of the columns in results, such that it ends up like the one I've shown in "resultsmean" below?

I've tried apply and lapply, still not got the correct arguments. As usual, TIA.

Jim

> results

[[1]]

       name    LOR23       BIA23       MSE23          H0R23
1 0.2111122   -1.012228   -0.095937    0.035650        1.00
2 0.2111122   -0.836300    0.079991    0.042322        0.75
3 0.2111122   -0.518631    0.397659    0.214593        0.50


[[2]]
       name    LOR23       BIA23       MSE23          H0R23
1 0.2211122   -0.724630    0.191660    0.051308           1
2 0.2211122   -0.781812    0.134478    0.033872           1
3 0.2211122   -0.522109    0.394181    0.164628        0.75


would like

> resultsmean

[[1]]

       name    LOR23       BIA23       MSE23          H0R23
1 0.2111122   -0.78333    0.12734     0.097160        0.75

[[2]]
       name    LOR23       BIA23       MSE23          H0R23
1 0.2211122   -0.67566    0.2400      0.08266         0.916

===============================

Dr. Jim Maas
University of East Anglia

R-help_at_r-project.org mailing list
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. Received on Sun 10 Apr 2011 - 15:34:12 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Sun 10 Apr 2011 - 17:00:28 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.

list of date sections of archive