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

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.

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