>In my programmer's head, something similar to this should "work": ... > deck[aCard]
There are some people who agree with you... see the data.table package, which can be made to behave like this. Keep in mind that the aCard data frame in general may have a different set of column names or more than one row. (I would be concerned that the logic of your application was inefficiently designed if `deck` actually has the same columns as `aCard` as in your example.) Others have pointed out that data frames are typically combined using the merge function, which allows matching columns to be specified very flexibly. On January 3, 2019 6:50:22 AM PST, Benoit Galarneau <benoit.galarn...@polymtl.ca> wrote: >Hi everyone, >I'm new to the R world. >Probably a newbie question but I am stuck with some concept with data >frame. >I am following some examples in the "Hands-On Programming with R". > >In short, how can I access/filter items in a data frame using a >variable. > >One example consists of manipulating elements from a deck of card: > >> deck > face suit value >1 king spades 13 >2 queen spades 12 >3 jack spades 11 >4 ten spades 10 >etc. > >Let's say I want to remove or filter out the first card. I know I >could do deck[-1]. > >But let's say I have: topCard <- deck[1,] > >topCard is then a list of 3 elements >> topCard > face suit value >1 king spades 13 > >My question is the following, how can I remove or filter out the deck >using the topCard variable. > >In my programmer's head, something similar to this should "work": >> deck[10,] > face suit value >10 four spades 4 >> aCard <- deck[10,] >> aCard > face suit value >10 four spades 4 >> deck[aCard] >Error in `[.default`(deck, aCard) : invalid subscript type 'list' > >Wihout having to specify all elements in the logical tests. > >deck[deck$face == aCard$face & deck$suit == aCard$suit & deck$value == > >aCard$value,] > face suit value >10 four spades 4 > >______________________________________________ >R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >https://stat.ethz.ch/mailman/listinfo/r-help >PLEASE do read the posting guide >http://www.R-project.org/posting-guide.html >and provide commented, minimal, self-contained, reproducible code. -- Sent from my phone. Please excuse my brevity. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
