Compare the lengths of two objects
Issue a warning or error if the lengths of two objects are not compatible.
compareLengths(x, y,
name.x=deparse(substitute(x), width.cutoff,
nlines=1, ...),
name.y=deparse(substitute(y), width.cutoff,
nlines=1, ...),
message0='', compFun=c('NROW', 'length'),
action=c(compatible='', incompatible='warning'),
length0=c('compatible', 'incompatible', 'stop'),
width.cutoff=20, ...)x, y |
objects whose lengths are to be compared |
name.x, name.y |
names of x and y to use in a message. Default =
|
message0 |
character string to be included with |
compFun |
function to use in the comparison. |
action |
A character vector of length 2 giving the names of functions to call if the lengths are not equal but are either 'compatible' or 'incompatible'; ” means no action. |
length0 |
If |
width.cutoff |
|
... |
optional arguments for |
1. If nchar(name.x) = 0 =
nchar(name.y), set name.x <- 'x',
name.y <- 'y', and append
'in compareLengths:' to message0
for more informative messaging.
2. lenx <- do.call(compFun, list(x));
leny <- do.call(compFun, list(y))
3. if(lenx==leny)return(c('equal', ''))
4. Compatible?
5. Compose the message.
6. "action", as indicated
A character vector of length 2. The first element is either 'equal', 'compatible' or 'incompatible'. The second element is the message composed.
Spencer Graves with help from Duncan Murdoch
##
## 1. equal
##
all.equal(compareLengths(1:3, 4:6), c("equal", ''))
##
## 2. compatible
##
a <- 1:2
b <- letters[1:6]
comp.ab <- compareLengths(a, b, message0='Chk:')
comp.ba <- compareLengths(b, a, message0='Chk:')
# check
chk.ab <- c('compatible',
'Chk: length(b) = 6 is 3 times length(a) = 2')
all.equal(comp.ab, chk.ab)
all.equal(comp.ba, chk.ab)
##
## 3. incompatible
##
Z <- LETTERS[1:3]
comp.aZ <- compareLengths(a, Z)
# check
chk.aZ <- c('incompatible',
' length(Z) = 3 is not a multiple of length(a) = 2')
all.equal(comp.aZ, chk.aZ)
##
## 4. problems with name.x and name.y
##
comp.ab2 <- compareLengths(a, b, '', '')
# check
chk.ab2 <- c('compatible',
'in compareLengths: length(y) = 6 is 3 times length(x) = 2')
all.equal(comp.ab2, chk.ab2)
##
## 5. zeroLength
##
zeroLen <- compareLengths(logical(0), 1)
# check
zeroL <- c('compatible', ' length(logical(0)) = 0')
all.equal(zeroLen, zeroL)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.