[R] Variable String formation

Roy Mendelssohn - NOAA Federal roy.mendelssohn at noaa.gov
Thu Sep 22 17:01:49 CEST 2016


Hi All:

I am trying to write code to create a string to be executed as a command.  The string will be of the form:

"param <- param[,rev(seq_len(dataYLen)),,drop = FALSE]"

Now just creating that string is simple enough.  Where the problem arises is the array param could be 2, 3, or 4 dimensions, and the dimension where  "rev(seq_len(dataYLen))" occurs can vary.  At present I have the following solution:

      paramLen <-  3
      latLoc <- 2
      myComma1 <- paste(rep(',', times = (latLoc-1)), 'rev(seq_len(dataYLen))', sep="", collapse="")
      myComma2 <- paste(rep(',', times = (paramLen-latLoc+1)),sep="", collapse="")
      paramCommand <- paste0('param <- param[', myComma1, myComma2, 'drop = FALSE]')

(paramLen can be 2,3,4 and latLoc can be 1,2,3,4)  but this strikes me as pretty kludgy.  I am hoping there is a more elegant way of doing this.

Thanks,

-Roy

**********************
"The contents of this message do not reflect any position of the U.S. Government or NOAA."
**********************
Roy Mendelssohn
Supervisory Operations Research Analyst
NOAA/NMFS
Environmental Research Division
Southwest Fisheries Science Center
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e-mail: Roy.Mendelssohn at noaa.gov www: http://www.pfeg.noaa.gov/

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