使用tidyverse时，确保你使用的是dplyr：：filter中的函数。filter正在寻找一个逻辑表达式，但你可能将它...
get_country_name<-function(city){w<-world.cities%>%filter(name==city)%>%arrange(desc(pop))%>%head(1)%>%pull(country.etc)return(w)}df%>%mutate(country=ifelse(is.na(country),unlist(sapply(locale,get_country_name)),country))
2 dplyr coerces characters to factors 1 Why do I get "Error: `...` is not empty" in R? 1 R: Error says invalid 'type' (character) of argument 8 Can't Combine X <character> and X <double> 0 Function in R: multi arguments is not permitted Hot Network Questions Determine ...
filter()picks cases based on their values. summarise()reduces multiple values down to a single summary. arrange()changes the ordering of the rows. These all combine naturally withgroup_by()which allows you to perform any operation “by group”. You can learn more about them invignette("dply...
Filter The second common function in dplyr is the filter() function. In this case, we want to filter data based on the row values, not the columns. For example, if we want to filter out all cars that have a gross weight over 4 tons, we would use the filter() function as follows:...
Basically, I just want to remind you and reiterate that if you want to save and continue working with the filtered data that comes out of thefilter()function, you need to save that data with a new name. Questions? Leave a comment below ...
Filtering joins, which filter observations from one table based on whether or not they match an observation in the other table:semi_join(),anti_join(). Set operations, which combine the observations in two data sets as if they were set elements:intersect(),union(),setdiff(). ...
src_localforworkingwithlocaldata Examples ##Notrun: if(require(microbenchmark)has_lahman()){ lahman_local-lahman_srcs(df,dt) teams-lapply(lahman_local,function(x)x%%tbl(Teams)) compare_tbls(teams,function(x)x%%filter(yearID==2010)) bench_tbls(teams,function(x)x%%filter(yearID==2010)) ...
noaa_tbl %>% filter(element == "TMAX") %>% compute() #> Error: Unable to create table when `RAthena_options(unload = TRUE)`. Please run `RAthena_options(unload = FALSE)` and try again. In general AWS Athena unload method is a nice way to speed up some queries when working with...
Find the book names of all US authors and who are not deceased. Well first we filter the authors table to filter out rows according the specified conditions. Then we can pass the result to aninner_join()statement to get the book titles and then we pass that result to select only the ...