Hello 1Hackers
Learn something Unique!
1) Explain what is R?
R is a data analysis software that is used by analysts, quants, statisticians, data scientists, and others.
2) List out some of the function that R provides?
The function that R provides are
 Mean
 Median
 Distribution
 Covariance
 Regression
 Nonlinear
 Mixed Effects
 GLM
 GAM. etc.
3) Explain how you can start the R commander GUI?
Typing the command, (“Rcmdr”) into the R console starts the R commander GUI.
4) In R how you can import Data?
You use R commander to import Data in R, and there are three ways through which you can enter data into it
 You can enter data directly via Data New Data Set
 Import data from a plain text (ASCII) or other files (SPSS, Minitab, etc.)
 Read a data set either by typing the name of the data set or selecting the data set in the dialog box
5) Mention what does not ‘R’ language do?
 Though R programming can easily connect to DBMS is not a database
 R does not consist of any graphical user interface
 Though it connects to Excel/Microsoft Office easily, R language does not provide any spreadsheet view of data
6) Explain how R commands are written?
In R, anywhere in the program, you have to preface the line of code with a #sign, for example

subtraction

division

note order of operations exists
7) How can you save your data in R?
To save data in R, there are many ways, but the easiest way of doing this is
Go to Data > Active Data Set > Export Active Data Set and a dialogue box will appear, when you click ok the dialogue box lets you save your data in the usual way.
8) Mention how you can produce corelations and covariances?
You can produce corelations by the cor () function to produce corelations and cov () function to produce covariances.
9) Explain what is ttests in R?
In R, the t.test () function produces a variety of ttests. The Ttest is the most common test in statistics and used to determine whether the means of two groups are equal to each other.
10) Explain what is With () and By () function in R is used for?
 With() function is similar to DATA in SAS, it applies an expression to a dataset.
 BY() function applies a function to each level of factors. It is similar to BY processing in SAS.
11) What are the data structures in R that are used to perform statistical analyses and create graphs?
R has data structures like
 Vectors
 Matrices
 Arrays
 Data frames
12) Explain the general format of Matrices in R?
General format is
Mymatrix<  matrix (vector, nrow=r , ncol=c , byrow=FALSE,
dimnames = list ( char_vector_ rowname, char_vector_colnames))
13) In R how missing values are represented ?
In R missing values are represented by NA (Not Available), why impossible values are represented by the symbol NaN (not a number).
14) Explain what is transpose?
For reshaping data before, analysis R provides a various methods and transposes are the simplest methods of reshaping a dataset. To transpose a matrix or a data frame t () function is used.
15) Explain how data is aggregated in R?
By collapsing data in R by using one or more BY variables, it becomes easy. When using the aggregate() function the BY variable should be on the list.
16) What is the function used for adding datasets in R?
rbind function can be used to join two data frames (datasets). The two data frames must have the same variables, but they do not have to be in the same order.
17) What is the use of subset() function and sample() function in R ?
In R, subset() functions help you to select variables and observations while through sample() function you can choose a random sample of size n from a dataset.
18) Explain how you can create a table in R without external file?
Use the code
myTable = data.frame()
edit(myTable)
This code will open an excellike spreadsheet where you can easily enter your data.