** 2-D data interpolation (table lookup). **

** ZI = INTERP2(X,Y,Z,XI,YI) returns matrix ZI containing elements **

** corresponding to the elements of XI and YI and determined by **

** interpolation within the 2-D function described by matrices X, Y, **

** and Z. Out of range values are returned as NaN. **

** **

** **

** X can be a row vector, in which case the elements are assumed to **

** apply to the columns of Z. Similarly, Y can be a column vector **

** and its elements are assumed to apply across the rows of Z. **

** **

** **

** Interpolation is the same operation as "table lookup". Described in **

** "table lookup" terms, the "table" is TAB = [NaN,Y; X,Z] and INTERP2 **

** "looks-up" the elements of XI in X, YI in Y, and, based upon their **

** location, returns values ZI interpolated within the elements of Z. **

** **

** **

** By default, INTERP2 uses bilinear interpolation. **

** ZI = INTERP2(X,Y,Z,XI,YI,'method') specifies alternate methods. **

** Available methods are: **

** **

** **

** 'linear' - bilinear interpolation **

** 'cubic' - bicubic interpolation **

** **

** **

** All the interpolation methods require that X and Y be monotonic. **

** The 'cubic' method also requires that the points in X and Y be **

** equally-spaced. **

** **

** **

** See also INTERP1 , GRIDDATA . **

** **