Check Numeric Trend
assert_constant(x, ...)assert_decreasing(x, ...)
assert_increasing(x, ...)
Throws an error, if any, and returns x invisibly otherwise.
A numeric object to be checked.
Extra parameters to be passed to internal methods.
N. Frerebeau
Other validation methods:
check-attribute,
check-data,
check-matrix,
check-numeric-comparison,
check-numeric,
check-type,
needs(),
validate()