**Sequences**

The regular sequences can be generated in R.

**Syntax :-**

seq ( )

seq (from = 1, to = 1, by = ( ( to - from) / (length.out - 1) ) , length.out = NULL, along.with = NULL, ....)

Examples:

> seq (10)

[1] 1 2 3 4 5 6 7 8 9 10

is the same as

> seq (1 : 10)

**Assignment of an index-vector**

> x <- c (9,8,7,6)

> ind <- seq (along = x)

> ind

[1] 1 2 3 4

**Accessing a value in the vector through index vector**

→ Accessing an element of an index-vector

> x [ind [2] ]

[1] 8

**Generating sequence of dates**

Generating current time and date

Sys.time ( ) command provides the current time and date from the computer system.

> Sys.time ( )

[1] "2017-01-01 09:17:01 IST"

Sys.Date ( ) command provides the current date from the computer system.

> Sys.Date ( )

[1] "2017-01-01"

**Usage**

seq (from, to, by, length.out = NULL, along.with = NULL, ...)

**Arguments**

from starting date (Required)

to end date (Optional)

by Increment of the sequence. "day" , "week" , "month" , "quarter" or "year".

length.out Integer, optional. Desired length of the sequence.

along.with take the length from the length of this argument.

**Sequence of first day of years**

> seq (as.Date ("2010-01-01") , as.Date ("2017-01-01"), by = "Years")

[1] "2010-01-01" "2011-01-01" "2012-01-01" "2013-01-01"

[5] "2014-01-01" "2015-01-01" "2016-01-01" "2017-01-01"

**Sequence of days**

> seq (as.Date ("2017-01-01") , by = "days", length = 6)

**Sequence of months**

> seq (as.Date ("2017-01-01") , by = "days", length = 6)

**Sequence of years**

> seq (as.Date ("2017-01-01") , by = "years", length = 6)

**To find sequence with defining start and end dates**

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