[R] How to choose columns in data.frame by parts of columns' names?

[Guo Wei-Wei]

Peter,

Thank you,
I made a mistake in my previous email. What I mean is:

data.new[,"G1"]  <- (data.old[,"XG1"] + data.old[,"YG1"])/2

Does your way have effects on data? or only have effects on those column names?
I tried on my data and get a list of numbers. Can I rearrange the
order of columns of data.frame by your way?

2006/5/31, Peter Alspach <PAlspach at hortresearch.co.nz>:
>
> Wei-wei
>
> yourNames
>  [1] "XG1"      "YG1"      "XEST"     "YEST"     "XNOEMP1"  "XNOEMP2"
>  [7] "YNOEMP1"  "YNOEMP2"  "XBUS10"   "XBUS10A"  "XBUS10B"  "XBUS10C"
> [13] "YBUS10"   "YBUS10A"  "YBUS10B"  "YBUS10C"  "XOWNBUS"  "XSELFEST"
> [19] "YOWNBUS"  "YSELFEST"
> yourNames[order(substring(yourNames,2), substring(yourNames, 1,1))]
>  [1] "XBUS10"   "YBUS10"   "XBUS10A"  "YBUS10A"  "XBUS10B"  "YBUS10B"
>  [7] "XBUS10C"  "YBUS10C"  "XEST"     "YEST"     "XG1"      "YG1"
> [13] "XNOEMP1"  "YNOEMP1"  "XNOEMP2"  "YNOEMP2"  "XOWNBUS"  "YOWNBUS"
> [19] "XSELFEST" "YSELFEST"
>
> gives an idea of what I mean .......
>
> Peter Alspach
>
>
>
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