spdim.m

function sp = spdim(n, d, options)
% SPDIM   Computes the number of sparse grid points
%    SP = SPDIM(N,D) Computes the number of points of the sparse
%    grid of dimension D and level N. 
%
%    SP = SPDIM(N,D,OPTIONS) Computes the number of points as
%    above, but with default grid type replaced by the grid type
%    specified in OPTIONS, an argument created with the SPSET
%    function. See SPSET for details.
%
%    See also SPINTERP, SPGRID, SPVALS. 

if nargin < 3, options = []; end

if d == 0
	% By definition; useful when computing recurrence formulae such
  % as Bungartz, "Finite Elements of Higher Order on Sparse
  % Grids", p.35, 1998.
	sp = 1;
	return;
end

gridtype = spget(options, 'GridType', 'Clenshaw-Curtis');

if strcmpi(gridtype, 'clenshaw-curtis')
	sp = spdimcc(n,d);
elseif strcmpi(gridtype, 'maximum')
	sp = spdimm(n,d);
elseif strcmpi(gridtype, 'noboundary')
	sp = spdimm(n,d,0);
elseif strcmpi(gridtype, 'chebyshev')
	% number of nodes same as CC-grid
	sp = spdimcc(n,d);
elseif strcmpi(gridtype, 'gauss-patterson')
	% number of nodes same as NB-grid
	sp = spdimm(n,d,0);
else
	error('MATLAB:spinterp:badopt',['Unknown grid type ''' gridtype '''.']);
end