[R] Subset returning unexpected result

[Steve Murray]

Dear all,

I am attempting to subset a data frame based on a range of latitude values. I want to extract the values of 'interception' where latitude ranges between 50 and 60. I am doing this using the following code, yet it doesn't return the results I expected:


> test <- subset(int1901, Latitude>=50 & Latitude <60, select=c(Latitude, Interception))


> head(test)
   Latitude Interception
2      6.25   0.04725863
3      6.75  67.02455139
82    50.75  51.74784088
83    51.25  57.04327774
84    51.75  51.51020432
85    52.25  53.30662537


As you can see, latitude values outside the 50 to 60 range have been retained (e.g. the top two rows of 'test'). Why is this, and how can I ensure that I subset the data as initially intended?

Many thanks for any help offered,

Steve