R4marketing | канал Алексея Селезнёва | Язык R. Страница 7

 
library("dplyr")
library("tidyr")
library("tidylog", warn.conflicts = FALSE)

 
filtered <- filter(mtcars, cyl == 4)
#> filter: removed 21 rows (66%), 11 rows remaining
mutated <- mutate(mtcars, new_var = wt ** 2)
#> mutate: new variable 'new_var' (double) with 29 unique values and 0% NA

 
summary <- mtcars %>%
    select(mpg, cyl, hp, am) %>%
    filter(mpg > 15) %>%
    mutate(mpg_round = round(mpg)) %>%
    group_by(cyl, mpg_round, am) %>%
    tally() %>%
    filter(n >= 1)
#> select: dropped 7 variables (disp, drat, wt, qsec, vs, …)
#> filter: removed 6 rows (19%), 26 rows remaining
#> mutate: new variable 'mpg_round' (double) with 15 unique values and 0% NA
#> group_by: 3 grouping variables (cyl, mpg_round, am)
#> tally: now 20 rows and 4 columns, 2 group variables remaining (cyl, mpg_round)
#> filter (grouped): no rows removed

 
extract - `[`
extract2 - `[[`
inset - `[<-`
inset2 - `[[<-`
use_series -`$`
add - `+`
subtract - `-`
multiply_by - `*`
raise_to_power - `^`
multiply_by_matrix - `%*%`
divide_by - `/`
divide_by_int - `%/%`
mod - `%%`
is_in - `%in%`
and - `&`
or - `|`
equals - `==`
is_greater_than - `>`
is_weakly_greater_than - `>=`
is_less_than - `<`
is_weakly_less_than - `<=`
not (`n'est pas`) - `!`
set_colnames -`colnames<-`
set_rownames - `rownames<-`
set_names - `names<-`
set_class - `class<-`
set_attributes - `attributes<-`
set_attr - `attr<-`

 
 iris %>%
   extract(, 1:4) %>%
   head

good.times <-
  Sys.Date() %>%
  as.POSIXct %>%
  seq(by = "15 mins", length.out = 100) %>%
  data.frame(timestamp = .)

good.times$quarter <-
  good.times %>%
  use_series(timestamp) %>%
  format("%M") %>%
  as.numeric %>%
  divide_by_int(15) %>%
  add(1)

 <- function(string){

  first <- unlist(strsplit(string, "\\{|\\}", fixed=F))
  inside_array <- unlist(strsplit(first[-1], ";", fixed=T))
  infomation_type <- substr(inside_array, 1,1)

  if(any(nchar(gsub("s|i", "", unique(infomation_type) )) != 0)){
    stop("unknow datatype in serilize data")
  }
  inside_array_s <- rep(NA, length(inside_array))

  pos <- infomation_type == "s"
  string_length <- as.numeric(sapply(strsplit(inside_array, ":", fixed=T), function(x) x[2]))[pos]
  inside_array_s[pos] <- substr(inside_array[pos], nchar(string_length)+4, nchar(inside_array[pos]))

  pos <- infomation_type == "i"
  inside_array_s[pos] <- substr(inside_array[pos],3,nchar(inside_array[pos]))

  # create key and value for each elment
  key <- inside_array_s[seq(1,length(inside_array_s),2)]
  value <- inside_array_s[seq(2,length(inside_array_s),2)]  

  return(cbind(key, value))
}

 
string <- 'a:1:{s:17:\"last_cart_refresh\";s:17:\"last_cart_refresh\";}'
php_unserialize(string)

     key                     value                  
[1,] "\"last_cart_refresh\"" "\"last_cart_refresh\""

 
names(animals)

 [1] "cow"          "chicken"      "chuck"        "clippy"      
 [5] "poop"         "bigcat"       "ant"          "pumpkin"     
 [9] "ghost"        "spider"       "rabbit"       "pig"         
[13] "snowman"      "frog"         "hypnotoad"    "shortcat"    
[17] "longcat"      "fish"         "signbunny"    "facecat"     
[21] "behindcat"    "stretchycat"  "anxiouscat"   "longtailcat" 
[25] "cat"          "trilobite"    "shark"        "buffalo"     
[29] "grumpycat"    "smallcat"     "yoda"         "mushroom"    
[33] "endlesshorse" "bat"          "bat2"         "turkey"      
[37] "monkey"       "daemon"       "egret"        "duckling"    
[41] "duck"         "owl"          "squirrel"     "squirrel2" 

 
say('Subscribe to R4marketing', 'cat')

 -------------- 
Subscribe to R4marketing 
 --------------
    \
      \
        \
            |\___/|
          ==) ^Y^ (==
            \  ^  /
             )=*=(
            /     \
            |     |
           /| | | |\
           \| | |_|/\
      jgs  //_// ___/
               \_)