Introduction_Command line_Data editor_Rstudio in R languages

Command Line versus Scripts

Execution of commands in R is not menu driven. (Not like Clicking over buttons to get outcome)

we need to type the commands.

Single line and multi line commands are possible to write.

When writing multi-line programs, it is useful to use a text editor rather than execute everything directly at the command line.

Option 1:

• One way use R's own built-in editor.
• It is accessible from the RGui menu bar.
• Click File and then click on New script. 

 
At this point R will open a window entitled Untitled-R Editor.

We may type and edit in this.

It we want to execute a line or a group of lines, just highlight them and press Ctrl+R.


Option 2:

Use R studio software

Suppose we want to use following three functions:

Type them.
library (MASS)
attach (bacteria)
fix (bacteria)

Suppose we want to run only function: library (MASS)

Highlight it and click on Run.

Data Editor

• There is a data editor within R that can be accessed from the menu bar by selecting Edit/Data editor.
• Provide the name of the matrix or data frame that we want to edit and a Data Editor window appears.
• Alternatively we can do this from the command line using the fix function. 

Example:
  library (MASS)
  attach (bacteria)
  fix (bacteria)

We can do it in R Studio as follows :

Cleaning up the Windows

• We assign names to variables when analyzing any data.
• It is good practice to remove the variable names give to any data frame at the end each session in R.
• This way, variable with same names but different properties will not get in each others way in subsequent work.
• rm ( ) command removes variable name
• For example,

           rm (x, y, z) removes the variable x, y and z.

• detach ( ) command detaches objects from the Search Path.
• It removes it from the search ( ) path of available R objects.
• Usually this is either a data.frame which has been attached or a package which was attached by library.
• To get rid of everything, including data frames, type rm (list=1s( )  ).