[R] if else statement for rain data to define zero for dry and one to wet

roslinazairimah zakaria roslinaump at gmail.com
Sat Jun 6 11:14:27 CEST 2015


Thank you jim.

On Saturday, June 6, 2015, Jim Lemon <drjimlemon at gmail.com> wrote:

> Hi rosalinazairimah,
> I think the problem is that you are using "if" instead of "ifelse". Try
> this:
>
> wet_dry<-function(x,thresh=0.1) {
>  for(column in 1:dim(x)[2]) x[,column]<-ifelse(x[,column]>=thresh,1,0)
>  return(x)
> }
> wet_dry(dt)
>
> and see what you get.
>
> Also, why can I read your message perfectly while everybody else can't?
>
> Jim
>
> >> -----Original Message-----
> >> From: roslinaump at gmail.com <javascript:;>
> >> Sent: Fri, 5 Jun 2015 16:49:08 +0800
> >> To: r-help at r-project.org <javascript:;>
> >> Subject: [R] if else statement for rain data to define zero for dry and
> >> one to wet
> >>
> >> Dear r-users,
> >>
> >> I have a set of rain data:
> >>
> >> X1950 X1951 X1952 X1953 X1954 X1955 X1956 X1957 X1958 X1959 X1960 X1961
> >> X1962
> >>
> >> 1   0.0   0.0  14.3   0.0  13.5  13.2   4.0     0   3.3     0     0
>  0.0
> >>
> >>
> >> 2   0.0   0.0  21.9   0.0  10.9   6.6   2.1     0   0.0     0     0
>  0.0
> >>
> >>
> >> 3  25.3   6.7  18.6   0.8   2.3   0.0   8.0     0   0.0     0     0
> 11.0
> >>
> >>
> >> 4  12.7   3.4  37.2   0.9   8.4   0.0   5.8     0   0.0     0     0
>  5.5
> >>
> >>
> >> 5   0.0   0.0  58.3   3.6  21.1   4.2   3.0     0   0.0     0     0
> 15.9
> >>
> >>
> >> I would like to go through each column and define each cell with value
> >> greater than 0.1 mm will be 1 and else zero. Hence I would like to
> attach
> >> the rain data and the category side by side:
> >>
> >>
> >> 1950   state
> >>
> >> 1 0.0    0
> >>
> >> 2 0.0    0
> >>
> >> 3 25.3   1
> >>
> >> 4 12.7   1
> >>
> >> 5 0.0    0
> >>
> >>
> >> ...
> >>
> >>
> >> This is my code:
> >>
> >>
> >> wet_dry  <- function(dt)
> >>
> >> { cl   <- length(dt)
> >>
> >>   tresh  <- 0.1
> >>
> >>
> >>   for (i in 1:cl)
> >>
> >>   {  xi <- dt[,i]
> >>
> >>      if (xi < tresh ) 0 else 1
> >>
> >>   }
> >>
> >> dd <- cbind(dt,xi)
> >>
> >> dd
> >>
> >> }
> >>
> >>
> >> wet_dry(dt)
> >>
> >>
> >> Results:
> >>
> >>> wet_dry(dt)
> >>
> >>    X1950 X1951 X1952 X1953 X1954 X1955 X1956 X1957 X1958 X1959 X1960
> >> X1961
> >> X1962 X1963 X1964 X1965 X1966 X1967 X1968 X1969 X1970 X1971 X1972 X1973
> >> X1974 X1975 X1976 X1977
> >>
> >> 1    0.0   0.0  14.3   0.0  13.5  13.2   4.0   0.0   3.3   0.0   0.0
> >> 0.0
> >>   4.2   0.0   2.2   0.0   4.4   5.1     0   7.2   0.0   0.0   0.0   5.1
> >> 0   0.0     0   0.3
> >>
> >> 2    0.0   0.0  21.9   0.0  10.9   6.6   2.1   0.0   0.0   0.0   0.0
> >> 0.0
> >>   8.4   0.0   4.0   0.0   4.9   0.7     0   0.0   0.0   0.0   0.0   5.4
> >> 0   3.3     0   0.3
> >>
> >> 3   25.3   6.7  18.6   0.8   2.3   0.0   8.0   0.0   0.0   0.0   0.0
> >> 11.0
> >>   4.2   0.0   2.0   0.0  14.2  17.1     0   0.0   0.0   0.0   0.0   2.1
> >> 0   1.7     0   4.4
> >>
> >> 4   12.7   3.4  37.2   0.9   8.4   0.0   5.8   0.0   0.0   0.0   0.0
> >> 5.5
> >>   0.0   0.0   5.4   0.0   6.4  14.9     0  10.1   2.9 143.4   0.0   6.1
> >> 0   0.0     0  33.5
> >>
> >>
> >> It does not work and give me the original data.  Why is that?
> >>
> >>
> >> Thank you so much for your help.
> >>
> >>       [[alternative HTML version deleted]]
> >>
> >> ______________________________________________
> >> R-help at r-project.org <javascript:;> mailing list -- To UNSUBSCRIBE and
> more, see
> >> 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.
>

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