firstContinue: The first/last values in a number sequence with a certain...

In paodan/funcTools: some useful function tools in practice

The first/last values in a number sequence with a certain step

Description

The first/last values in a number sequence with a certain step

Usage

firstContinue(v = p0, step = 1, last = FALSE, showWarning = TRUE)

Arguments

v	a numeric vector.
step	numeric, the step in the number sequence that you are interested
last	logical, if TRUE the last values in the sequence are returned. Default is FALSE, by which the first values are returned.
showWarning	logical, whether to show warning. Default is TRUE.

Value

a vector of first/last values in the sequence with a certain step. This vector also contains an attribute (index), which shows the index of these first/last values in the vector v.

Examples

# Number sequence is: (1, 2, 3), (5, 6, 7, 8, 9), (12), (22)
x = c(1:3, 5:9, 12, 22)
print(x)

# to show the first values in a number sequence with step = 1
firstContinue(x)
# To show the last values in a number sequence with step = 1
firstContinue(x, last = TRUE)

# (100), (10, 9), (3, 2, 1), (-10) 
x = c(100, 10, 9, 3, 2, 1, -10)
print(x)

# To show the first values in a number sequence with step = 1
firstContinue(x, -1)
# to show the last values in a number sequence with step = 1
firstContinue(x, -1, last = TRUE)

x = c(100, 10, 9, 3, 3, 3, 2, 1, 1, 1, -10)
# when step is 0, it is equivalent to unique function.
firstContinue(x, 0)
unique(x)

# When x is not sorted, by default a warning will be raised
# (100), (10, 9), (3, 2, 1), (11, 10), (-10)
x = c(100, 10, 9, 3, 2, 1, 11, 10, -10)
print(x)
firstContinue(x, -1)
# To suppress warning
firstContinue(x, -1, showWarning = FALSE)

paodan/funcTools documentation built on April 1, 2024, 12:01 a.m.