[R] coercing a list to a data frame, lists in foreloops

[Gabor Grothendieck]

Benjamin M. Osborne <Benjamin.Osborne <at> uvm.edu> writes:

: 
: I have a set of time-series climate data with missing entries.  I need to add
: rows for these missing entries to this data set.  The only way I know to do
: this is unsing a foreloop, but this won't work on a list.  I've tried to
: convert the list to a data frame, but that won't happen, either.
: 
: I want to fill rows in this table:
: 
: > newtest[10:15,]
:     yrmos yearmo snow.sum snow.mean snow.dep.mean prcp.sum prcp.mean tmin.min
: 10 195410     NA       NA        NA            NA       NA        NA       NA
: 11 195411     NA       NA        NA            NA       NA        NA       NA
: 12 195412     NA       NA        NA            NA       NA        NA       NA
: 13 195501     NA       NA        NA            NA       NA        NA       NA
: 14 195502     NA       NA        NA            NA       NA        NA       NA
: 15 195503     NA       NA        NA            NA       NA        NA       NA
:    tmin.mean tmax.max tmax.mean tmean.mean
: 10        NA       NA        NA         NA
: 11        NA       NA        NA         NA
: 12        NA       NA        NA         NA
: 13        NA       NA        NA         NA
: 14        NA       NA        NA         NA
: 15        NA       NA        NA         NA
: >
: 
: from this one:
: 
: > mansNew[10:15,]
:    yearmo snow.sum snow.mean snow.dep.mean prcp.sum prcp.mean  tmin.min
: 10 195508    0.000 0.0000000       0.00000  29.5910 0.9545484        NA
: 11 195509    0.000 0.0000000       0.00000   9.1948 0.3064933        NA
: 12 195510   20.320 0.6554839            NA  13.8684 0.4473677        NA
: 13 195511       NA        NA            NA       NA        NA -18.88889
: 14 195512   52.324 1.6878710      53.01226   6.4770 0.2089355        NA
: 15 195601   46.736 1.5076129            NA   8.0264 0.2589161        NA
:    tmin.mean   tmax.max  tmax.mean tmean.mean
: 10        NA         NA         NA         NA
: 11        NA         NA         NA         NA
: 12        NA         NA         NA         NA
: 13  -8.62963 12.2222222 -0.6481481  -4.638889
: 14        NA -0.5555556 -9.3906810         NA
: 15        NA         NA         NA         NA
: >
: This may be a problem:
: > newtest<-as.data.frame(newtest)
: > mode(newtest)  ## returns "list"
: [1] "list"
: >
: > mansNew<-as.data.frame(mansNew)
: > mode(mansNew)  ## returns "list"
: [1] "list"
: >
: I've checked to make sure each column is a vector, but the coercion still is 
not
: allowed.
: 
: This is the code with which I'm attempting to perform this manipulation, as 
well
: as the result:
: 
: > for (i in 1:100){
: + newtest[i,2:12]<-ifelse(is.element(newtest$yrmos[i],mansNew$yearmo),
: subset(mansNew, yearmo == newtest$yrmos[i])[,1:11], c(rep(NA,11)))
: + }
: > newtest[10:15,]
:     yrmos yearmo snow.sum snow.mean snow.dep.mean prcp.sum prcp.mean tmin.min
: 10 195410     NA       NA        NA            NA       NA        NA       NA
: 11 195411 195411   195411    195411        195411   195411    195411   195411
: 12 195412 195412   195412    195412        195412   195412    195412   195412
: 13 195501 195501   195501    195501        195501   195501    195501   195501
: 14 195502 195502   195502    195502        195502   195502    195502   195502
: 15 195503 195503   195503    195503        195503   195503    195503   195503
:    tmin.mean tmax.max tmax.mean tmean.mean
: 10        NA       NA        NA         NA
: 11    195411   195411    195411     195411
: 12    195412   195412    195412     195412
: 13    195501   195501    195501     195501
: 14    195502   195502    195502     195502
: 15    195503   195503    195503     195503
: >
: 
: subset...  should return only one row.  This may be a simple comma problem, 
but
: I think it has something to do with the lists.  Also, if there is a way to do
: this without the foreloop, I'd be happy to hear about it.
: Any suggestions will be appreciated.

The zoo package has facilities for this:

R> library(zoo)

R> # create a 3x2 zoo matrix whose rows correspond to time points 1,3,4
R> z <- zoo(matrix(1:6, 3), c(1,3,4))

R> # merge z with 0 dimensional zoo series having time points 1,2,3,4
R> merge(z, zoo(,c(1,2,3,4)))
  z.1 z.2
1  1   4 
2 NA  NA 
3  2   5 
4  3   6