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

[Jim Lemon]

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
>> Sent: Fri, 5 Jun 2015 16:49:08 +0800
>> To: r-help at r-project.org
>> 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]]
>>
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