https://github.com/cran/pracma
Tip revision: c1688b374d201c13fb40b4dda2d2a89e34b94ec6 authored by Hans W. Borchers on 23 January 2021, 09:10:02 UTC
version 2.3.3
version 2.3.3
Tip revision: c1688b3
compan.R
###
### COMPAN.R Polynom
###
compan <- function(p) {
if (length(p) == 0) return(c())
if ( !is.vector(p, mode="numeric") &&
(!is.vector(p, mode="complex")) )
stop("Argument p must be a vector of real or complex numbers.")
while(p[1] == 0 && length(p) >= 2) {
p <- p[2:length(p)]
}
n <- length(p)
if (n <= 1) {
a <- c()
} else {
if (n == 2) {
a <- -p[2]/p[1]
} else {
a <- diag(0, n-1, n-1)
for (i in 2:(n-1)) {
a[i, i-1] <- 1
}
a[1, ] <- -p[2:n]/p[1]
}
}
return(a)
}