Matlab test functions.

humps(x)
sinc(x)
psinc(x, n)

Arguments

x

numeric scalar or vector.

n

positive integer.

Details

humps is a test function for finding zeros, for optimization and integration. Its root is at x = 1.2995, a (local) minimum at x = 0.6370, and the integral from 0.5 to 1.0 is 8.0715.

sinc is defined as \(sinc(t) = \frac{\sin(\pi t)}{\pi t}\). It is the continuous inverse Fourier transform of the rectangular pulse of width \(2\pi\) and height \(1\).

psinc is the 'periodic sinc function' and is defined as \(psinc(x,n) = \frac{\sin(x n/2)}{n \sin(x/2)}\).

Value

Numeric scalar or vector.

Examples

if (FALSE) { # \dontrun{
plot(humps(), type="l"); grid()

x <- seq(0, 10, length=101)
plot(x, sinc(x), type="l"); grid()
} # }