Programming with R: Part-1

R Codes
Press Enter on your keyboard to execute. 

Code	Purpose
2+2	Add 2 with 2
1:10	Get values 1 thru 10
201:300	Get values 201 thru 300
a=2	Assign value of a to 2. Note: This does not mean a is equal to 2. That purpose is met by a==2.
a	Know assigned value of a
b=3	Assign value of b to 2.
a*b	Multiply a with b
a^b	a to the power b
log(a)	Log of a Note: By default log is natural i.e. with base e which we call ln. That is the code log(2) is tantamount to ln(2). Keep in mind that ln(2) is unavailable in R.
log(2)	Log of 2
exp(1)	e to the power 1.
?log	Get help about log. To get other help topics, type similarly like ?sum
log (x, base=7)	Usual format for value of log (x) with base 7
log (base=10, x=a)	Detail format of log
log (a,10)	Shortcut format for log
choose (12, 8)	Number of possible combinations of taking 8 object out of 12. That is, it’s analogous to 12C8
gamma(5)	Value of Γ5 that is, 4!
factorial (8)	8! i.e. 8 factorial
exp (2.3)	e2.3
sqrt (8.4)	Square root of 9.4
beta (2,3)	B(a,b) = Γ(a)Γ(b)/Γ(a+b).
round(2.34)	Rounding
round(2.34567, 4)	Rounding up to 4 decimal
pi	3.1416… i.e. value of π
abs (-2)	Absolute value of (-2)
class (b)	See the type of object b
class (log)	See class of log
sqrt (beta(7,9))	Square root of this beta value
log(17) +1	Same as code

Courtesy: Dr. Jafor Ahmed Khan
Profesor, Dept. of Statistics, Biostatistics & Informatics, University of Dhaka