[R] how can I convert a long to wide matrix?

[Jim Lemon]

Hi Marna,
Try this:

library(prettyR)
stretch_df(dat,idvar="ID",to.stretch=c("EventDate","SITE"))

Jim


On Wed, May 2, 2018 at 8:24 AM, Marna Wagley <marna.wagley using gmail.com> wrote:
> Hi R user,
> I was trying to convert a long matrix to wide? I have an example and would
> like to get a table (FinalData1):
>
>
> FinalData1
>          B1    B2
> id_X   "A"   "B"
> id_Y   "A"   "B"
>
> but I got the following table using the following code.
>
> FinalData1
>
>      B1  B2
>
> id_X "A" "A"
>
> id_Y "A" "B"
>
>
> the code and the example data I used are given below. Is there any
> suggestions to fix the problem?
>
>
> dat<-structure(list(ID = structure(c(1L, 1L, 1L, 2L, 2L), .Label = c("id_X",
>
>
> "id_Y"), class = "factor"), EventDate = structure(c(4L, 5L, 2L,
>
> 3L, 1L), .Label = c("9/15/16", "9/15/17", "9/7/16", "9/8/16",
>
> "9/9/16"), class = "factor"), timeGroup = structure(c(1L, 1L,
>
> 2L, 1L, 2L), .Label = c("B1", "B2"), class = "factor"), SITE = structure(c(
> 1L,
>
> 1L, 2L, 1L, 2L), .Label = c("A", "B"), class = "factor")), .Names = c("ID",
>
> "EventDate", "timeGroup", "SITE"), class = "data.frame", row.names = c(NA,
>
> -5L))
>
>
> tmp <- split(dat, dat$ID)
>
> tmp1 <- do.call(rbind, lapply(tmp, function(dat){
>
> tb <- table(dat$timeGroup)
>
> idx <- which(tb>0)
>
> tb1 <- replace(tb, idx, as.character(dat$SITE))
>
> }))
>
>
> tmp1
>
> FinalData<-print(tmp1, quote=FALSE)
>
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>
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