function [w,ierr] = besseli(nu,z,scale)
%BESSELI Modified Bessel function of the first kind.
% I = BESSELI(NU,Z) is the modified Bessel function of the first kind,
% I_nu(Z). The order NU need not be an integer, but must be real.
% The argument Z can be complex. The result is real where Z is positive.
% If NU and Z are arrays of the same size, the result is also that size.
% If either input is a scalar, it is expanded to the other input's size.
% If one input is a row vector and the other is a column vector, the
% result is a two-dimensional table of function values.
% I = BESSELI(NU,Z,1) scales I_nu(z) by exp(-abs(real(z)))
% [I,IERR] = BESSELI(NU,Z) also returns an array of error flags.
% ierr = 1 Illegal arguments.
% ierr = 2 Overflow. Return Inf.
% ierr = 3 Some loss of accuracy in argument reduction.
% ierr = 4 Complete loss of accuracy, z or nu too large.
% ierr = 5 No convergence. Return NaN.
% besseli(3:9,(0:.2:10)',1) generates the entire table on page 423
% of Abramowitz and Stegun, Handbook of Mathematical Functions.
% This M-file uses a MEX interface to a Fortran library by D. E. Amos.
% See also BESSELJ, BESSELY, BESSELK, BESSELH.
% D. E. Amos, "A subroutine package for Bessel functions of a complex
% argument and nonnegative order", Sandia National Laboratory Report,
% SAND85-1018, May, 1985.
% D. E. Amos, "A portable package for Bessel functions of a complex
% argument and nonnegative order", Trans. Math. Software, 1986.
% Copyright 1984-2001 The MathWorks, Inc.
% $Revision: 5.15 $ $Date: 2001/04/15 12:01:40 $
if nargin == 2, scale = 0; end
[msg,nu,z,siz] = besschk(nu,z); error(msg);
[w,ierr] = besselmx(real('I'),nu,z,scale);
if ~isempty(w) & all(all(imag(w) == 0)), w = real(w); end
w = reshape(w,siz);