r - R: How select rows form a csv, that match rows of another csv in R?

Question

I have one csv file which contains 3 columns (species name, longitude, and latitude.) and a second csv file which contains a column with species names. What I want to do is to extract from the first csv the species (also the long and lat columns) that match the species in the second csv file.

How can I do this in R?

Answer 1

 ## Read csv files
 file1 = read.csv(paste(path, "file1.csv", sep = ""), stringsAsFactors = FALSE, na.strings = "NA")
 file2 = read.csv(paste(path, "file2.csv", sep = ""), stringsAsFactors = FALSE, na.strings = "NA")


 #> file1
 #  Species Longitude   Latitude
 #1     Cat 0.4300052 0.04554442
 #2     Dog 0.6568743 0.53359425
 #3    Fish 0.8218709 0.20328321
 #4    Deer 0.4601183 0.93191142
 #5     Cow 0.9975495 0.02349226


 #> file2
 #  Species
 #1    Fish
 #2     Dog


 ## Get subset in first file of species in second file
 result = file1[file1$Species %in% file2$Species,]

You get:

 #> result
 #  Species Longitude  Latitude
 #2     Dog 0.6568743 0.5335943
 #3    Fish 0.8218709 0.2032832