extend.pc {NCmisc}

Extend an interval by percentage

Description

For various reasons, such as applying windows, setting custom range limits for plots, it may be desirable to extend an interval by a certain percentage.

Usage

extend.pc(X, pc = 0.5, pos = TRUE, neg = TRUE, swap = FALSE)

Arguments

X

a numeric range, should be length 2. If a longer numeric, will be coerced with range()

pc

percentage by which to extend X, can be entered in either percentage style: 0<pc<1; or 1<pc<100

pos

logical, if TRUE, make an extension in the positive direction

neg

logical, if TRUE, make an extension in the negative direction

swap

logical, if TRUE, flip the extension directions if X[2]<X[1], ie, not in numerical order

Examples

extend.pc(c(2,10),0.25) # extend X symmetrically
extend.pc(c(2:10),0.25) # extend the range of X
# the following 3 examples extend X by 1% only in the 'positive' direction
extend.pc(c(25000,55000),.01,neg=FALSE) # standard positive extension
extend.pc(c(55000,25000),.01,neg=FALSE) # ranges in reverse order, not swapped
extend.pc(c(55000,25000),.01,neg=FALSE,swap=TRUE) # ranges in reverse order, swapped