interp2 — Interpolate values on two-dimensional grids in MATLAB and RunMat.
interp2(X, Y, Z, Xq, Yq) estimates surface values at query points from gridded data. Meshgrid-style coordinates and implicit-axis forms are supported, consistent with MATLAB semantics.
Syntax
Vq = interp2(Z, Xq, Yq)
Vq = interp2(X, Y, Z, Xq, Yq)
Vq = interp2(Z, Xq, Yq, method)
Vq = interp2(X, Y, Z, Xq, Yq, method)
Vq = interp2(Z, Xq, Yq, extrap)
Vq = interp2(X, Y, Z, Xq, Yq, extrap)
Vq = interp2(Z, Xq, Yq, method, extrap)
Vq = interp2(X, Y, Z, Xq, Yq, method, extrap)Inputs
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
Z | Any | Yes | — | Grid sample matrix. |
Xq | Any | Yes | — | Query X coordinates. |
Yq | Any | Yes | — | Query Y coordinates. |
X | Any | Yes | — | Grid X axis vector or mesh. |
Y | Any | Yes | — | Grid Y axis vector or mesh. |
method | StringScalar | No | "linear" | Interpolation method: "linear" or "nearest". |
extrap | Any | No | NaN | Extrapolation mode: "extrap" or scalar fill value. |
Returns
| Name | Type | Description |
|---|---|---|
Vq | NumericArray | Interpolated values over a 2-D grid. |
Errors
| Identifier | When | Message |
|---|---|---|
RunMat:interp2:InvalidArgument | Argument count, method/extrapolation options, or axis/query compatibility is invalid. | interp2: invalid argument |
RunMat:interp2:InvalidInput | Grid or query values cannot be converted to numeric interpolation domains. | interp2: invalid input |
RunMat:interp2:Internal | Interpolation output construction fails due to internal tensor assembly paths. | interp2: internal interpolation failure |
How interp2 works
- Supports
linearandnearestmethods in the initial implementation. - Out-of-range query points return
NaNunless an extrapolation value or'extrap'is supplied. - Dense real numeric inputs are supported. GPU inputs gather to the host reference path.
Examples
Bilinear interpolation with implicit axes
Z = [1 2; 3 4];
zq = interp2(Z, 1.5, 1.5)Expected output:
zq = 2.5Interpolation with meshgrid axes
[X, Y] = meshgrid([10 20], [100 200]);
Z = [1 2; 3 4];
zq = interp2(X, Y, Z, 15, 150)Expected output:
zq = 2.5Using interp2 with coding agents
Open a RunMat example with live inputs, then ask the agent to explain how interp2 changes the result.
Run a small interp2 example, explain the result, then change one input and compare the output.
Related Math functions
Elementwise
abs · angle · bsxfun · complex · conj · double · erf · erfcinv · exp · expm1 · factorial · flintmax · gamma · gammaln · heaviside · hypot · idivide · imag · intmax · intmin · ldivide · log · log10 · log1p · log2 · minus · nextpow2 · plus · pow2 · power · rdivide · real · realmax · realmin · realsqrt · rescale · sign · single · sqrt · swapbytes · times · uint32
Trigonometry
acos · acosh · asin · asinh · atan · atan2 · atanh · cos · cosd · cosh · cospi · deg2rad · pol2cart · rad2deg · sin · sind · sinh · sinpi · tan · tand · tanh
Reduction
all · any · bounds · cummax · cummin · cumprod · cumsum · cumtrapz · diff · gradient · max · maxk · mean · median · min · mink · movmax · movmean · movmedian · movmin · movprod · movstd · movsum · movvar · nnz · prod · rms · std · sum · trapz · var
Structure
bandwidth · isdiag · ishermitian · issymmetric · istril · istriu · symrcm
Signal
blackman · butter · buttord · cheb2ord · conv · conv2 · deconv · downsample · envelope · filter · filtfilt · fir1 · freqz · gauspuls · hamming · hann · hilbert · periodogram · pulstran · pwelch · rectpuls · resample · sawtooth · sinc · spectrogram · square · tripuls · unwrap · upsample · zplane
Optim
coneprog · fminbnd · fminunc · fsolve · fzero · integral · linprog · lsqcurvefit · lsqnonlin · optimset · quad · secondordercone
Ops
cross · ctranspose · dot · mldivide · mpower · mrdivide · mtimes · pagemtimes · pagetranspose · trace · transpose
Open-source implementation
Unlike proprietary runtimes, every RunMat function is open-source. Read exactly how interp2 is executed, line by line, in Rust.
- View the source for interp2 in Rust on GitHub
- Learn how the RunMat runtime works
- Found a bug? Open an issue with a minimal reproduction.
About RunMat
RunMat is an open-source runtime that executes MATLAB-syntax code blazing on any GPU. It is licensed under the Apache 2.0 license.
- RunMat automatically optimizes your math for GPU execution on Apple, Nvidia, and AMD hardware. No code changes needed. Simulations that took hours now take minutes.
- Start running code in seconds. RunMat runs in the browser, on the desktop, or from the CLI. No license server, no IT ticket.