Converting geo coordinates from degree to decimal

Question

I want to convert my geographic coordinates from degrees to decimals, my data are as follows:

         lat     long
105252 30°25.264 9°01.331
105253 30°39.23         


        

Answer 1

A bit of vectorization and matrix manipulation will make your function much simpler:

x <- read.table(text="
       lat     long
105252 30°25.264 9°01.331
105253 30°39.237 8°10.811
105255 31°37.760 8°06.040
105258 31°41.190 8°06.557
105259 31°41.229 8°06.622
105260 31°38.891 8°06.281",
                header=TRUE, stringsAsFactors=FALSE)

x

The function itself makes use of:

• strsplit() with the regex pattern "[°\\.]" - this does the string split in one step
• sapply to loop over the vector

Try this:

convert<-function(x){
  z <- sapply((strsplit(x, "[°\\.]")), as.numeric)
  z[1, ] + z[2, ]/60 + z[3, ]/3600
} 

Try it:

convert(x$long)
[1] 9.108611 8.391944 8.111111 8.254722 8.272778 8.178056

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Disclaimer: I didn't check your math. Use at your own discretion.