# griddedInterpolant

Gridded data interpolation

## Description

Use `griddedInterpolant`

to perform interpolation on a 1-D,
2-D, 3-D, or N-D gridded data set.
`griddedInterpolant`

returns the interpolant
`F`

for the given data set. You can evaluate `F`

at a
set of query points, such as `(xq,yq)`

in 2-D, to produce interpolated
values `vq = F(xq,yq)`

.

Use `scatteredInterpolant`

to perform
interpolation with scattered data.

## Creation

### Syntax

### Description

creates an
empty gridded data interpolant object.`F`

= griddedInterpolant

creates a 2-D, 3-D, or N-D interpolant using a full
grid of sample points passed as a set of
`F`

= griddedInterpolant(`X1`

,`X2`

,...,`Xn`

,`V`

)`n`

-dimensional arrays `X1,X2,...,Xn`

. The
`V`

array contains the sample values associated with the
point locations in `X1,X2,...,Xn`

. Each of the arrays
`X1,X2,...,Xn`

must be the same size as
`V`

.

uses the default grid to create the interpolant. When you use this syntax,
`F`

= griddedInterpolant(`V`

)`griddedInterpolant`

defines the grid as a
set of points whose spacing is `1`

and range is
[`1`

, `size(V,i)`

] in the
`i`

th dimension. Use this syntax when you want to conserve
memory and are not concerned about the absolute distances between points.

specifies a cell array `F`

= griddedInterpolant(`gridVecs`

,`V`

)`gridVecs`

that contains
`n`

grid vectors to
describe an `n`

-dimensional grid of sample points. Use this
syntax when you want to use a specific grid and also conserve memory.

specifies the interpolation method: `F`

= griddedInterpolant(___,`Method`

)`'linear'`

,
`'nearest'`

, `'next'`

,
`'previous'`

, `'pchip'`

,
`'cubic'`

, `'makima'`

, or
`'spline'`

. You can specify `Method`

as
the last input argument in any of the previous syntaxes.

specifies both the interpolation and extrapolation methods. `F`

= griddedInterpolant(___,`Method`

,`ExtrapolationMethod`

)`griddedInterpolant`

uses
`ExtrapolationMethod`

to estimate the value when your query
points fall outside the domain of your sample points.

### Input Arguments

## Properties

## Usage

Use `griddedInterpolant`

to create the interpolant, `F`

. Then you can evaluate
`F`

at specific points using any of the following syntaxes:

`Vq = F(Xq)`

Vq = F(xq1,xq2,...,xqn)

Vq = F(Xq1,Xq2,...,Xqn)

Vq = F({xgq1,xgq2,...,xgqn})

`Vq = F(Xq)`

specifies the query points in the matrix`Xq`

. Each row of`Xq`

contains the coordinates of a query point.`Vq = F(xq1,xq2,...,xqn)`

specifies the query points`xq1,xq2,...,xqn`

as column vectors of length`m`

representing`m`

points scattered in`n`

-dimensional space.`Vq = F(Xq1,Xq2,...,Xqn)`

specifies the query points using the`n`

-dimensional arrays`Xq1,Xq2,...,Xqn`

, which define a full grid of points.`Vq = F({xgq1,xgq2,...,xgqn})`

specifies the query points as grid vectors. Use this syntax to conserve memory when you want to query a large grid of points.

## Examples

## More About

## Tips

It is quicker to evaluate a

`griddedInterpolant`

object`F`

at many different sets of query points than it is to compute the interpolations separately using`interp1`

,`interp2`

,`interp3`

, or`interpn`

. For example:% Fast to create interpolant F and evaluate multiple times F = griddedInterpolant(X1,X2,V) v1 = F(Xq1) v2 = F(Xq2) % Slower to compute interpolations separately using interp2 v1 = interp2(X1,X2,V,Xq1) v2 = interp2(X1,X2,V,Xq2)

## Extended Capabilities

## See Also

`scatteredInterpolant`

| `interp1`

| `interp2`

| `interp3`

| `interpn`

| `ndgrid`

| `meshgrid`

| `fillmissing`

| `filloutliers`

**Introduced in R2011b**