kutils (version 1.73)

padW0: Insert 0's in the front of existing digits or characters so that all elements of a vector have the same number of characters.

Description

The main purpose was to correct ID numbers in studies that are entered as integers with leading 0's as in 000001 or 034554. R's default coercion of integers will throw away the preceding 0's, and reduce that to 1 or 34554. The user might want to re-insert the 0's, thereby creating a character vector with values "000001" and "045665".

Usage

padW0(x, n = 0)

Value

A character vector

Arguments

x

vector to be converted to a character variable by inserting 0's at the front. Should be integer or character, floating point numbers will be rounded down. All other variable types will return errors.

n

Optional parameter. The desired final length of character vector. This parameter is a guideline to determine how many 0's must be inserted. This will be ignored if n is smaller than the number of characters in the longest element of x.

Author

Paul Johnson <[e-mail]>

Details

If x is an integer or a character vector, the result is the more-or-less expected outcome (see examples). If x is numeric, but not an integer, then x will be rounded to the lowest integer.

The previous versions of this function failed when there were missing values (NA) in the vector x. This version returns NA for those values.

One of the surprises in this development was that sprintf() in R does not have a known consequence when applied to a character variable. It is platform-dependent (unredictable). On Ubuntu Linux 16.04, for example sprintf("%05s", 2) gives back " 2", rather than (what I expected) "00002". The problem is mentioned in the documentation for sprintf. The examples show this does work now, but please test your results.

Examples

x1 <- c(0001, 0022, 3432, NA)
padW0(x1)
padW0(x1, n = 10)
x2 <- c("1", "22", "3432", NA)
padW0(x2)
## There's been a problem with strings, but this works now.
## It even preserves non-leading spaces. Hope that's what you want.
x3 <- c("1", "22 4", "34323  42", NA)
padW0(x3)
x4 <- c(1.1, 334.52, NA)
padW0(x4)