download.file() function 
////////////////////////////
inFile<-'https://www.sec.gov/Archives/edgar/full-index/2020/QTR2/company.zip'

outFile<-'2020Q2.zip'

download.file(inFile,outFile,mode ="wb",method = "libcurl")

/////////////////////////

Installations of three R packages: png and httr
////////////////////////////////
My  .existRemoteFile function depends on the 'httr' R package
My  .codeImage       function depends on the 'png' R package.
My  .read_clip and .write_clip functions depend on the 'clipr'. 

To install an R package, we have the following two methods. 
Method I:
---------
  >install.packages('png')
  >install.packages('httr')
  >install.packages('clipr')

Method II:
----------
  click 'Packages' on the menu bar
        --> Click 'Install Package(s)...'
        --> [choose a location[]
        --> [choose 'png' from the list ]
            Again [choose 'httr' from the list]

 In Chapter 12, Introduction to R packages, 
     I will  introduce Method III. 

/////////////////////////

All built-in data sets 
////////////////////////////

infile<-'http://datayyy.com/data_R/builtInRData.RData'
 load(url(infile))

/////////////////////////

read.csv() and read.table()
////////////////////////////
 x<- read.csv('http://datayyy.com/data_csv/ibmDaily.csv')

 y<- read.table('http://datayyy.com/data_txt/sp500annual.txt')

path<-'https://archive.ics.uci.edu/ml/machine-learning-databases/iris/'
data<-'iris.data'
inFile<-paste0(path,data)
x<-read.csv(inFile,header=F)

/////////////////////////

review a few functions 
////////////////////////////////
read.csv()
read.table()
readLines()
load()
load() url()
get() load() url()

read.fwf

To find a few input files, issue the following command. 

  .sw('c5_input')


If no output after issuing the above line, type
  .explain(16)

/////////////////////////

ff3Monthly.RData
////////////////////////////////
 The location of the file is

   http://datayyy.com/data_R/ff3Monthly.RData

  Task #1: download the data set

  Task #2: how many rows and columns

  Task #3: choose one column or one row

  Task #4: choose a subset

/////////////////////////