简单来说就是 二维数据插值
下面是matlab给出的解释
INTERP2 2-D interpolation (table lookup)。
ZI = INTERP2(X,Y,Z,XI,YI) interpolates to find ZI, the values of the
underlying 2-D function Z at the points in matrices XI and YI。
Matrices X and Y specify the points at which the data Z is given。
XI can be a row vector, in which case it specifies a matrix with
constant columns。
Similarly, YI can be a column vector and it
specifies a matrix with constant rows。
ZI = INTERP2(Z,XI,YI) assumes X=1:N and Y=1:M where [M,N]=SIZE(Z)。
ZI = INTERP2(Z,NTIMES) expands Z by interleaving interpolates between
every element, working recursively for NTIMES。
INTERP2(Z) is the
same as INTERP2(Z,1)。
ZI = INTERP2(。。。,METHOD) specifies alternate methods。 The default
is linear interpolation。
Available methods are:
‘nearest’ – nearest neighbor interpolation
‘linear’ – bilinear interpolation
‘spline’ – spline interpolation
‘cubic’ – bicubic interpolation as long as the data is
uniformly spaced, otherwise the same as ‘spline’
For faster interpolation when X and Y are equally spaced and monotonic,
use the syntax ZI = INTERP2(。
。。,*METHOD)。
ZI = INTERP2(。。。,METHOD,EXTRAPVAL) specificies a method and a scalar
value for ZI outside of the domain created by X and Y。
Thus, ZI will
equal EXTRAPVAL for any value of YI or XI which is not spanned by Y
or X respectively。 A method must be specified for EXTRAPVAL to be used,
the default method is ‘linear’。
All the interpolation methods require that X and Y be monotonic and
plaid (as if they were created using MESHGRID)。
If you provide two
monotonic vectors, interp2 changes them to a plaid internally。
X and Y can be non-uniformly spaced。
For example, to generate a coarse approximation of PEAKS and
interpolate over a finer mesh:
[x,y,z] = peaks(10); [xi,yi] = meshgrid(-3:。
1:3,-3:。
1:3);
zi = interp2(x,y,z,xi,yi); mesh(xi,yi,zi)
Class support for inputs X, Y, Z, XI, YI:
float: double, single。
全部