因此照原格式输出4spread(test, grade) %>%5#spread:Spread a key-value pair across multiple columns.6mutate(class=parse_number(class)) %>%7#parse_numeric Extract numeric component of variable.8print
library(nycflights13) library(dplyr) # 选择部分数据方便演示 flights2 <- flights %>% select(year:day, hour, origin, dest, tailnum, carrier) glimpse(flights2) ## Rows: 336,776 ## Columns: 8 ## $ year <int> 2013, 2013, 2013, 2013, 2013, 2013, 2013, 2013, 2013, 2013, 20~ ##...
c("DepTime","ArrTime","FlightNum")]# dplyr approachselect(flights,DepTime,ArrTime,FlightNum)# use colon to select multiple contiguous columns, and use `contains` to match columns by name# note: `starts_with`, `ends_with`, and `matches` (for regular expressions) can also be used to ma...
they have the same columns, and the columns have compatible types. A few distinct() failures, probably related to: distinct() returns columns ordered the way you request, not the same as the input data (#6156). ── Failure ('test-dplyr-join.R:30'): left_join──────────...
n_distinct(x):不相同的观测值的个数 first(x),last(x)和nth(x, n)获取第一个,最后一个,和第n个数据 ```{r first and last value} summarise(tbl, first = first(odate), last = last(odate)) # A tibble: 1 × 2 # first last ...
isbest-suitedforinteractiveuse,distinct_()forcallingfromafunction. Usage distinct(.data,...) distinct_(.data,...,.dots) Arguments .dataatbl ...Variablestousewhendetermininguniqueness.Iftherearemultiplerowsfora givencombinationofinputs,onlythefirstrowwillbep. .dotsUsedtoworkaroundnon-standardevaluat...
# 计算非空值sum(!is.na(x)),计算唯一值:n_distinct(x) # Which destinations have the most carriers? not_cancelled %>% group_by(dest) %>% summarize(carriers = n_distinct(carrier)) %>% arrange(desc(carriers)) # 计数:n(),和count() not_cancelled %>% count(dest) not_cancelled %>% ...
1. All the lanes occupied by the vehicle. The current lane is given in the "Lane" column. All the other lanes which the vehicle moved to are the target lanes. I want to create new columns containing the lane numbers of all target lanes i.e.target.lane1,target.lan...
5 sum columns values in data.table in r using .SDcols 4 How to calculate row medians efficiently with data.table 0 create new row and column by summing multiple column and row 44 Efficient row-wise operations on a data.table 4 Row wise operation on data.table 1 Summing the prod...
The SQL translation ofn_distinct()now accepts multiple variables (#2148). copy_to()now returns it's output invisibly (since you're often just calling for the side-effect). Infand-Infare now correctled escaped for databases. Long deprecatedregroup()has been removed. ...