qgriddata

This function takes unevenly distributed data in vectors X,Y,Z,V and returns data in arrays XG,YG,ZG,VG which are suitable for use in Matlab functions such as SLICE.

For any valid I, X(I),Y(I),Z(I),V(I) defines the x,y and z coordinates of data with a scalar value V(I) associated with that coordinate.

This function is much faster than using GRIDDATA for large data sets as it does not attempt any interpolation. Instead, the function searches for data points which fall in a particular cell of dimensions DX,DY,DZ. The mean of all the points in the cell is returned in VG. If there are no data points inside that volume then NaN is returned, i.e. THERE IS NO INTERPOLATION. For this reason, if DX,DY or DZ are set too small the function will not be effective.