it looks great, thank you very much Jeff for your time and kind help ! On Wed, Jul 18, 2018 at 7:51 PM, Jeff Newmiller <jdnew...@dcn.davis.ca.us> wrote:
> The traditional (SQL) way to attack this problem is to make the data > structure simpler so that faster comparisons can be utilized: > > ################ > A <- data.frame(z=c("a*b", "c*d", "d*e", "e*f"), t =c(1, 2, 3, 4)) > B <- data.frame(z=c("a*b::x*y", "c", "", "g*h"), t =c(1, 2, 3, 4)) > > library(dplyr) > #> > #> Attaching package: 'dplyr' > #> The following objects are masked from 'package:stats': > #> > #> filter, lag > #> The following objects are masked from 'package:base': > #> > #> intersect, setdiff, setequal, union > library(tidyr) > Bx <- ( B > %>% mutate( z_B = as.character( z ) ) > %>% rename( t_B = t ) > %>% separate_rows( z, sep="::" ) > ) > Bx > #> z t_B z_B > #> 1 a*b 1 a*b::x*y > #> 2 x*y 1 a*b::x*y > #> 3 c 2 c > #> 4 3 > #> 5 g*h 4 g*h > result <- ( A > %>% mutate( z = as.character( z ) ) > %>% rename( t_A = t ) > %>% inner_join( Bx, by="z" ) > ) > result > #> z t_A t_B z_B > #> 1 a*b 1 1 a*b::x*y > > #' Created on 2018-07-18 by the [reprex package](http://reprex.tidyver > se.org) (v0.2.0). > ################ > > Note that this is preferable if you can avoid ever creating the complex > data z in B, but Bx is much more flexible and less error prone than B. > (Especially if you don't have to create B$z_B at all, but have some other > unique identifier(s) for the groupings represented by each row in B.) > > > On Wed, 18 Jul 2018, Bogdan Tanasa wrote: > > Thanks a lot ! It looks that I am getting the same results with : >> >> B %>% regex_left_join(A, by = c(z = 'z')) >> >> On Wed, Jul 18, 2018 at 3:57 PM, Riley Finn <rileyfi...@gmail.com> wrote: >> >> please may I ask for a piece of advise regarding merging two dataframes : >>> >>>> A <- data.frame(z=c("a*b", "c*d", "d*e", "e*f"), t =c(1, 2, 3, 4)) >>>> B <- data.frame(z=c("a*b::x*y", "c", "", "g*h"), t =c(1, 2, 3, 4)) >>>> function of the criteria : >>>> if "the elements in the 1st column of A could be found among the >>>> elements >>>> of the 1st column of B" i.e. >>>> for the example above, we shall combine in the results only the row with >>>> "a*b" of A with the row with "a*b::x*y" of B. >>>> >>> >>> >>> This may be what you are looking for: >>> >>> library(fuzzyjoin) >>> >>> The inner join returns just the one row where the string matches. >>> B %>% >>> regex_inner_join(A, by = c(z = 'z')) >>> >>> While the full join returns NA's where the string does not match. >>> B %>% >>> regex_full_join(A, by = c(z = 'z')) >>> >>> On Wed, Jul 18, 2018 at 5:20 PM Bogdan Tanasa <tan...@gmail.com> wrote: >>> >>> Dear all, >>>> >>>> please may I ask for a piece of advise regarding merging two dataframes >>>> : >>>> >>>> A <- data.frame(z=c("a*b", "c*d", "d*e", "e*f"), t =c(1, 2, 3, 4)) >>>> >>>> B <- data.frame(z=c("a*b::x*y", "c", "", "g*h"), t =c(1, 2, 3, 4)) >>>> >>>> function of the criteria : >>>> >>>> if "the elements in the 1st column of A could be found among the >>>> elements >>>> of the 1st column of B" i.e. >>>> >>>> for the example above, we shall combine in the results only the row with >>>> "a*b" of A with the row with "a*b::x*y" of B. >>>> >>>> thank you, >>>> >>>> bogdan >>>> >>>> [[alternative HTML version deleted]] >>>> >>>> ______________________________________________ >>>> 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. >>>> >>>> >>> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> 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/posti >> ng-guide.html >> and provide commented, minimal, self-contained, reproducible code. >> >> > ------------------------------------------------------------ > --------------- > Jeff Newmiller The ..... ..... Go Live... > DCN:<jdnew...@dcn.davis.ca.us> Basics: ##.#. ##.#. Live > Go... > Live: OO#.. Dead: OO#.. Playing > Research Engineer (Solar/Batteries O.O#. #.O#. with > /Software/Embedded Controllers) .OO#. .OO#. rocks...1k > ------------------------------------------------------------ > --------------- > [[alternative HTML version deleted]] ______________________________________________ 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.