Interpolation
You can look at this decision tree figure created several years ago to help you figure out which interpolation or regridding routine to use. This is a bit out-of-date; we'll try to update it when we can.For regridding routines, see the full list in the regridding category list.
area_conserve_remap | Performs areal conservative remapping from one rectilinear grid to another. |
area_conserve_remap_Wrap | Performs areal conservative remapping from one rectilinear grid to another and retains metadata. |
area_hi2lores | Interpolates from high resolution rectilinear grids to low resolution recitlinear grids using local area averaging. |
area_hi2lores_Wrap | Interpolates from high resolution rectilinear grids to low resolution rectilinear grids using local area averaging and retains metadata. |
bin_avg | Calculates gridded binned averages and counts on a rectilinear grid using randomly spaced data. |
csa1 | Calculates an approximating cubic spline for the input data, one 1-dimensional section at a time. |
csa1d | Calculates an approximating cubic spline for the input data, one 1-dimensional section at a time. |
csa1s | Calculates an approximating cubic spline for the input data, one 1-dimensional section at a time. |
csa1x | Calculates an approximating cubic spline for the input data, one 1-dimensional section at a time. |
csa1xd | Calculates an approximating cubic spline for the input data, one 1-dimensional section at a time. |
csa1xs | Calculates an approximating cubic spline for the input data, one 1-dimensional section at a time. |
csa2 | Calculates an approximating cubic spline for two-dimensional input data. |
csa2d | Calculates an approximating cubic spline for two-dimensional input data. |
csa2l | Calculates an approximating cubic spline for two-dimensional input data. |
csa2ld | Calculates an approximating cubic spline for two-dimensional input data. |
csa2ls | Calculates an approximating cubic spline for two-dimensional input data. |
csa2lx | Calculates an approximating cubic spline for two-dimensional input data. |
csa2lxd | Calculates an approximating cubic spline for two-dimensional input data. |
csa2lxs | Calculates an approximating cubic spline for two-dimensional input data. |
csa2s | Calculates an approximating cubic spline for two-dimensional input data. |
csa2x | Calculates an approximating cubic spline for two-dimensional input data. |
csa2xd | Calculates an approximating cubic spline for two-dimensional input data. |
csa2xs | Calculates an approximating cubic spline for two-dimensional input data. |
csa3 | Calculates an approximating cubic spline for three-dimensional input data. |
csa3d | Calculates an approximating cubic spline for three-dimensional input data. |
csa3l | Calculates an approximating cubic spline for three-dimensional input data. |
csa3ld | Calculates an approximating cubic spline for three-dimensional input data. |
csa3ls | Calculates an approximating cubic spline for three-dimensional input data. |
csa3lx | Calculates an approximating cubic spline for three-dimensional input data. |
csa3lxd | Calculates an approximating cubic spline for three-dimensional input data. |
csa3lxs | Calculates an approximating cubic spline for three-dimensional input data. |
csa3s | Calculates an approximating cubic spline for three-dimensional input data. |
csa3x | Calculates an approximating cubic spline for three-dimensional input data. |
csa3xd | Calculates an approximating cubic spline for three-dimensional input data. |
csa3xs | Calculates an approximating cubic spline for three-dimensional input data. |
csc2s | Converts Cartesian coordinates on a unit sphere to spherical coordinates (lat/lon). |
csgetp | Retrieves control parameters for Cssgrid routines. |
css2c | Converts spherical coordinates (lat/lon) to Cartesian coordinates on a unit sphere. |
cssetp | Sets control parameters for Cssgrid routines. |
cssgrid | Uses tension splines to interpolate unstructured (randomly-spaced) data on a unit sphere to data values on a rectilinear grid. |
cssgrid_Wrap | Uses tension splines to interpolate unstructured (randomly-spaced) data on a unit sphere to data values on a rectilinear grid (retains metadata). |
csstri | Calculates a Delaunay triangulation of data randomly positioned on the surface of a sphere. |
csvoro | Determines Voronoi polygons for data randomly positioned on a sphere and returns vertices for the one surrounding a specified input point. |
curvilinear_to_SCRIP | Writes the description of a curvilinear grid to a SCRIP file. |
dsgetp | Gets parameters for Dsgrid routines. |
dsgrid2 | Interpolates data from an unstructured (randomly-spaced) grid to a rectilinear grid using inverse distance weighted interpolation. |
dsgrid2d | Interpolates double data from an unstructured (randomly-spaced) grid to a rectilinear grid using inverse distance weighted interpolation. (Deprecated version.) |
dsgrid2s | Interpolates float data from an unstructured (randomly-spaced) grid to a rectilinear grid using inverse distance weighted interpolation. (Deprecated version.) |
dsgrid3 | Interpolates data from an unstructured (randomly-spaced) grid to a 3D grid using inverse distance weighted interpolation. |
dsgrid3d | Interpolates double data from an unstructured (randomly-spaced) grid to a 3D grid using inverse distance weighted interpolation. (Deprecated version.) |
dsgrid3s | Interpolates float data from an unstructured (randomly-spaced) grid to a 3D grid using inverse distance weighted interpolation. (Deprecated version.) |
dspnt2 | Interpolates 2D data at specified points. |
dspnt2d | Interpolates 2D data at specified points. (Deprecated version.) |
dspnt2s | Interpolates 2D float data at specified points. (Deprecated version.) |
dspnt3 | Interpolates 3D data at specified points. |
dspnt3d | Interpolates 3D double data at specified points. (Deprecated version.) |
dspnt3s | Interpolates 3D float data at specified points. (Deprecated version.) |
dssetp | Sets parameters for Dsgrid routines. |
ESMF_regrid | Regrids data from one lat/lon grid to another, using ESMF software. |
ESMF_regrid_gen_weights | Writes a weight file using the offline ESMF weight generator. |
ESMF_regrid_with_weights | Using the provided weight file, regrids data from one lat/lon grid to another. |
ftcurv | Calculates an interpolatory spline through a sequence of functional values. |
ftcurvd | Calculates the derivatives of an interpolatory spline under tension. |
ftcurvi | Calculates integrals of an interpolatory spline under tension between two user-specified limits. |
ftcurvp | Calculates an interpolatory spline under tension through a sequence of functional values for a periodic function. |
ftcurvpi | Calculates an integral of an interpolatory spline between two specified points. |
ftcurvps | Calculates a smoothing spline. |
ftcurvs | Calculates a smoothing spline. |
ftgetp | Retrieves control parameters for Fitgrid routines. |
ftkurv | Calculates an interpolatory spline for parametric curves. |
ftkurvd | Calculates an interpolatory spline for parametric curves; it also calculates first and second derivatives of the interpolatory spline. |
ftkurvp | Calculates an interpolatory spline under tension through a sequence of points in the plane forming a closed curve. |
ftkurvpd | Calculates an interpolatory spline for closed parametric curves; it also calculates first and second derivatives of the interpolatory spline. |
ftsetp | Sets control parameters for Fitgrid routines. |
ftsurf | Calculates an interpolatory surface passing through a rectangular grid of function values. |
idsfft | Interpolates 2D random data. |
int2p | Interpolates pressure levels to a different set of pressure levels. |
int2p_n | Interpolates pressure levels to a different set of pressure levels on the given dimension. |
int2p_n_Wrap | Interpolates pressure levels to a different set of pressure levels and returns metadata. |
int2p_Wrap | Interpolates pressure levels to a different set of pressure levels and returns metadata. |
latlon_to_SCRIP | Writes the description of a lat/lon grid to a SCRIP file. |
linint1 | Interpolates from one series to another using piecewise linear interpolation across the rightmost dimension. |
linint1_n | Interpolates from one series to another using piecewise linear interpolation across the given dimension. |
linint1_n_Wrap | Interpolates from one series to another using piecewise linear interpolation across the given dimension, and retains metadata. |
linint1_Wrap | Interpolates from one series to another using piecewise linear interpolation, and retains metadata. |
linint2 | Interpolates from a rectilinear grid to another rectilinear grid using bilinear interpolation. |
linint2_points | Interpolates from a rectilinear grid to an unstructured grid or locations using bilinear interpolation. |
linmsg | Linearly interpolates to fill in missing values. |
linmsg_n | Linearly interpolates to fill in missing values, given the dimension to do the interpolation across. |
natgrid | Interpolates data from an unstructured (randomly-spaced) grid to a rectilinear grid using natural neighbor interpolation. |
natgrid_Wrap | Interpolates data from an unstructured (randomly-spaced) grid to a rectilinear grid using natural neighbor interpolation and retains metadata. |
natgridd | Interpolates double data on an unstructured grid to a rectilinear grid. (Deprecated version.) |
natgrids | Interpolates float data on an unstructured grid to a rectilinear grid. (Deprecated version.) |
nngetaspectd | Retrieves an aspect at a specified coordinate position. |
nngetaspects | Retrieves an aspect at a specified coordinate position. |
nngetp | Retrieves control parameters for Natgrid routines. |
nngetsloped | Retrieves a slope at a specified coordinate position. |
nngetslopes | Retrieves a slope at a specified coordinate position. |
nngetwts | Retrieves natural neighbors and weights for the function values at those neighbors. |
nngetwtsd | Retrieves natural neighbors and weights for the function values at those neighbors. |
nnpnt | Interpolates from 2D random data to get values at a specified set of points. |
nnpntd | Interpolates from 2D random double data to get values at a specified set of points. (Deprecated version.) |
nnpntend | Terminates interpolation from 2D random data to get values at a specified set of points. |
nnpntendd | Terminates interpolation from 2D random data to get values at a specified set of points. |
nnpntinit | Initializes internal quantities, for given input data, to allow subsequent nnpnt calls to interpolate at specified points. |
nnpntinitd | Initializes internal quantities, for given input data, to allow subsequent nnpntd calls to interpolate at specified points. |
nnpntinits | Initializes internal quantities, for given input data, to allow subsequent nnpnts calls to interpolate at specified points. |
nnpnts | Interpolates from 2D random float data to get values at a specified set of points. (Deprecated version.) |
nnsetp | Sets control parameters for Natgrid routines. |
obj_anal_ic | Iterative improvement objective analysis. |
obj_anal_ic_deprecated | Iterative correction objective analysis (Cressman, Barnes) (deprecated) |
obj_anal_ic_Wrap | Iterative improvement objective analysis and returns meta data. |
poisson_grid_fill | Replaces all missing (_FillValue) values in a grid with values derived from solving Poisson's equation via relaxation. |
rcm2points | Interpolates data on a curvilinear grid (i.e. RCM, WRF, NARR) to an unstructured grid. |
rcm2rgrid | Interpolates data on a curvilinear grid (i.e. RCM, WRF, NARR) to a rectilinear grid. |
rectilinear_to_SCRIP | Writes the description of a rectilinear grid to a SCRIP file. |
rgrid2rcm | Interpolates data on a rectilinear lat/lon grid to a curvilinear grid like those used by the RCM, WRF and NARR models/datasets. |
shgetnp | Finds the nearest point, or points (in a specified set of points), to a given point in 3-space. |
shgetp | Retrieves control parameters for Shgrid routines. |
shgrid | Interpolates data from an unstructured grid to a grid in 3-space. |
shsetp | Sets control parameters for Shgrid routines. |
sigma2hybrid | Interpolates from sigma to hybrid coordinates. |
trop_wmo | Determines the level of the thermal tropopause. |
unstructured_to_ESMF | Writes the description of an unstructured grid to an ESMF file. |
wrf_interp_1d | Linearly interpolates a one-dimensional variable in the vertical. |
wrf_interp_2d_xy | Extracts a cross section from a given input field. |
wrf_interp_3d_z | Interpolates to a specified pressure/height level. |
wrf_user_interp_level | Interpolates a horizontal slice from a three-dimensional WRF-ARW field at the given vertical level(s). |
wrf_user_interp_line | Interpolates a two-dimensional WRF-ARW field along a line. |
wrf_user_intrp2d | Interpolates ARW WRF 2D model data along a given line (deprecated). |
wrf_user_intrp3d | Interpolates ARW WRF model data vertically or horizontally (deprecated). |
wrf_user_unstagger | Unstaggers an input variable along a specified dimension. |
wrf_user_vert_cross | Interpolates a vertical cross-section from a three-dimensional WRF-ARW field at the given vertical level(s). |
wrf_user_vert_interp | Vertically interpolates ARW WRF variables given the type of surface and a set of new levels. |