dtint.m

MDPSAS工具箱是马里兰大学开发的

function val = dtint(A,R)

% dtint.m Discrete-transform-based interpolation of a
%         (1D) scalarfield object to a set of points within
%         the range of the scalarfield's quadgrid object
%
%	INPUT parameters:
%               A : a 1D scalarfield object 
%               R : one or more points
%
%	OUTPUT:
%	        B : a double array
%
% Note: For the interpolation to work, A must be completely
% defined (i.e., no NaN)

Aval  = get(A,'val');
Apd   = get(A,'pd');

I = find(~(Aval > -realmax & Aval < realmax)); % returns indices of NaN elements
if prod(length(I)) > 0, error('A must be completely defined (no NaN)'), end

geomOld  = get(Apd,'geom');
qpOld    = get(Apd,'qp');
nameOld  = get(Apd,'name');
Qinv     = get(Apd,'Qinv');

if length(nameOld) >= 2
   error('Not yet set up for higher-dimensional scalarfield objects')
   end

PrintExtrapolationWarning = 0;

%%%%%%%%%%%%%%% 1D to 1D interpolation %%%%%%%%%%%%%%%

if length(nameOld) == 1

   [val,extrapflag] = ...
       dtint(qpOld{1},Aval,R,Qinv{1},geomOld{1});
   if extrapflag, PrintExtrapolationWarning = 1; end

   end

if PrintExtrapolationWarning
      warning('Extrapolation produced NaN entries in output');
      end