[R] Conditional operation on multiple columns from two data frames

tsippel tsippel at gmail.com
Mon Dec 29 01:27:01 CET 2008

The suggestion below was made.

df1$Date <- as.Date(df1$Date)
df2$Date <- as.Date(df2$Date)
ifelse(df1$ID==df2$ID & df1$Date-df2$Date<0.5,df1$y-df2$y, NA)

However, because my dataframe rows do not align, I need the conditionals to
be tested on every combination of cells.  I'm starting to think I need to
use tapply?  

View this message in context: http://www.nabble.com/Conditional-operation-on-multiple-columns-from-two-data-frames-tp21189891p21197566.html
Sent from the R help mailing list archive at Nabble.com.

More information about the R-help mailing list