Importing Data Files
Spreadsheet (Excel) file data
The xlsx package has the function read.xlsx ( ) for reading Excel files.
This will read the first sheet of an Excel spreadsheet.
To read Excel files, we first need to install the package
install.packages ("xlsx")
library (xlsx)
data <- read.xlsx ("datafile.xlsx", sheet Index or sheet Name)
To load other sheets with read.xlsx( ), we specify a number for sheetIndex or a name for sheetName:
data <- read.xlsx("datafile.xlsx", sheetIndex=2)
data <- read.xlsx("datafile.xlsx",sheetName="marks")
For reeading older Excel files in .xls format, use gdata package and function read.xls ( )
This will read the first sheet of an Excel spreadsheet.
To read Excel files, we first need to install the package
install.packages ("gdata")
library (gdata)
data <- read.xls ("datafile.xls", sheet Index or sheet Name) )
SPSS data file
For reading SPSs data files, use foreign package and function read.spss ( )
To read SPSs files, we first need to install the package
install.packages ("foreign")
library (foreign)
data <- read.spss ("datafile.sav")
Other data files
The foreign package also includes functions to load other formats, including:
Contents of working directory
The list.files function shows the contents of your working directory:
> list.files ( ) // List of all available files in the working directory.
> setwd ("C:/RCourse/")
> list.files ( )
Redirecting Output to a File
Issue:
We want to redirect the output from R into a file instead of your console.
Solution:
Redirect the output of the cat function by using its file argument:
> ans <- 6 + 8
> cat ("The answer of 6 + 8 is", ans, "\n", file="filename")
The Output will be saved in the working directory with given filename.
Use the sink function to redirect all the output from both print and cat.
Call sink with a filename argument to begin redirecting console output to that file.
When we are done, sink with no argument to close the file and resume output to the console.
> sink ("filename") #Beign writing output to file
.....other session work .....
> sink
The print and cat functions normally write the output to console.
The cat function redirects the output to a file if we supply a file argument.
The print function cannot redirect its output.
The sink function can force all output to a file.
Redirecting Output to a File: Three steps
1.
> sink ("output.txt") # Redirect output to file
2.
> source ("script.R") # Run the script, capture its output
3.
> sink ( ) # Resume writing output to console
Other options like append=TRUE/FALSE, split=TRUE/FALSE are available.
Example :-
Spreadsheet (Excel) file data
The xlsx package has the function read.xlsx ( ) for reading Excel files.
This will read the first sheet of an Excel spreadsheet.
To read Excel files, we first need to install the package
install.packages ("xlsx")
library (xlsx)
data <- read.xlsx ("datafile.xlsx", sheet Index or sheet Name)
To load other sheets with read.xlsx( ), we specify a number for sheetIndex or a name for sheetName:
data <- read.xlsx("datafile.xlsx", sheetIndex=2)
data <- read.xlsx("datafile.xlsx",sheetName="marks")
For reeading older Excel files in .xls format, use gdata package and function read.xls ( )
This will read the first sheet of an Excel spreadsheet.
To read Excel files, we first need to install the package
install.packages ("gdata")
library (gdata)
data <- read.xls ("datafile.xls", sheet Index or sheet Name) )
SPSS data file
For reading SPSs data files, use foreign package and function read.spss ( )
To read SPSs files, we first need to install the package
install.packages ("foreign")
library (foreign)
data <- read.spss ("datafile.sav")
Other data files
The foreign package also includes functions to load other formats, including:
- read.octave ("<Path to file>") : Octave and MATLAB
- read.systat ("<Path to file>") : SYSTAT
- read.xport ("<Path to file>") " SAS XPORT
- read.data ("<Path to file>") : Stata
Contents of working directory
The list.files function shows the contents of your working directory:
> list.files ( ) // List of all available files in the working directory.
> setwd ("C:/RCourse/")
> list.files ( )
Redirecting Output to a File
Issue:
We want to redirect the output from R into a file instead of your console.
Solution:
Redirect the output of the cat function by using its file argument:
> ans <- 6 + 8
> cat ("The answer of 6 + 8 is", ans, "\n", file="filename")
The Output will be saved in the working directory with given filename.
Use the sink function to redirect all the output from both print and cat.
Call sink with a filename argument to begin redirecting console output to that file.
When we are done, sink with no argument to close the file and resume output to the console.
> sink ("filename") #Beign writing output to file
.....other session work .....
> sink
The print and cat functions normally write the output to console.
The cat function redirects the output to a file if we supply a file argument.
The print function cannot redirect its output.
The sink function can force all output to a file.
Redirecting Output to a File: Three steps
1.
> sink ("output.txt") # Redirect output to file
2.
> source ("script.R") # Run the script, capture its output
3.
> sink ( ) # Resume writing output to console
Other options like append=TRUE/FALSE, split=TRUE/FALSE are available.
Example :-
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