eta {pracma}

Dirichlet Eta Function

Description

Dirichlet's eta function valid in the entire complex plane.

Usage

eta(z)

Arguments

z

Real or complex number or a numeric or complex vector.

Details

Computes the eta function for complex arguments using a series expansion.

Accuracy is about 13 significant digits for abs(z)<100, drops off with higher absolute values.

Value

Returns a complex vector of function values.

Note

Copyright (c) 2001 Paul Godfrey for a Matlab version available on Mathwork's Matlab Central under BSD license.

References

Zhang, Sh., and J. Jin (1996). Computation of Special Functions. Wiley-Interscience, New York.

See Also

gammaz, zeta

Examples

z <- 0.5 + (1:5)*1i
eta(z)
z <- c(0, 0.5+1i, 1, 1i, 2+2i, -1, -2, -1-1i)
eta(z)