| rat(rational) | R Documentation |
rat(x, leng=6, maxm=100, name="rational.so")
x |
numeric data object for which the rational approximation is needed. |
leng |
maximum length of the continued fraction used. |
maxm |
maximum partial denominator. If any partial denominator
exceeds maxm the continued fraction terminates at that point. |
name |
name of object file containing the dynamically loaded C function. |
list of two components, $a and $b, containing the numerators and the denominators of the rational approximations respectively.
rat() can be viewed as providing a speculative way of removing
roundoff error if the correct answer should be rational numbers with
"small" denominators.
rational() and fractions() which use rat()
# solve() accuracy check using a small Hilbert Matrix
x <- matrix(0,5,5); x <- 1/(row(x) + col(x) -1)
# confirm:
rat(x)
x1 <- solve(solve(x)); x2 <- rat(x1)
# compare:
x-x1
# with:
x-x2$num/x2$den