piping.R

ls()

## character(0)

rm(list=ls())
gc()

##          used (Mb) gc trigger (Mb) max used (Mb)
## Ncells 292392  7.9     460000 12.3   350000  9.4
## Vcells 321652  2.5     786432  6.0   677529  5.2

memory.size()

## [1] 14.13

memory.limit()

## [1] 1535

#data can be also downloaded from http://bit.ly/dsdata

getwd()

## [1] "C:/Users/dell/Desktop/Teaching"

dir("C:/Users/dell/Desktop/",pattern=".csv")

## [1] "Analytics decisionstats.com Audience Overview 20110617-20120717.csv"
## [2] "BigDiamonds.csv"                                                    
## [3] "BigDiamonds.csv.zip"                                                
## [4] "Boston.csv"                                                         
## [5] "ccFraud.csv"                                                        
## [6] "test.csv"

library(data.table)

sessionInfo()

## R version 3.2.2 (2015-08-14)
## Platform: i386-w64-mingw32/i386 (32-bit)
## Running under: Windows 7 (build 7601) Service Pack 1
## 
## locale:
## [1] LC_COLLATE=English_United States.1252 
## [2] LC_CTYPE=English_United States.1252   
## [3] LC_MONETARY=English_United States.1252
## [4] LC_NUMERIC=C                          
## [5] LC_TIME=English_United States.1252    
## 
## attached base packages:
## [1] stats     graphics  grDevices utils     datasets  methods   base     
## 
## other attached packages:
## [1] data.table_1.9.4
## 
## loaded via a namespace (and not attached):
##  [1] plyr_1.8.3      magrittr_1.5    tools_3.2.2     htmltools_0.2.6
##  [5] reshape2_1.4.1  Rcpp_0.12.1     stringi_0.5-5   rmarkdown_0.7  
##  [9] knitr_1.10.5    stringr_1.0.0   digest_0.6.8    chron_2.3-47   
## [13] evaluate_0.7

diamonds=fread("C:/Users/dell/Desktop/BigDiamonds.csv")

## 
Read 3.3% of 598024 rows
Read 8.4% of 598024 rows
Read 13.4% of 598024 rows
Read 18.4% of 598024 rows
Read 25.1% of 598024 rows
Read 30.1% of 598024 rows
Read 36.8% of 598024 rows
Read 41.8% of 598024 rows
Read 45.1% of 598024 rows
Read 50.2% of 598024 rows
Read 55.2% of 598024 rows
Read 60.2% of 598024 rows
Read 65.2% of 598024 rows
Read 66.9% of 598024 rows
Read 71.9% of 598024 rows
Read 76.9% of 598024 rows
Read 81.9% of 598024 rows
Read 87.0% of 598024 rows
Read 90.3% of 598024 rows
Read 93.6% of 598024 rows
Read 598024 rows and 13 (of 13) columns from 0.049 GB file in 00:00:29

mean(diamonds$price,na.rm=T)

## [1] 8753.018

library(magrittr)
diamonds$price %>% na.omit %>% mean

## [1] 8753.018

mean(na.omit(diamonds$price))

## [1] 8753.018

#vignette("magrittr")
#?multiply_by