`isgpuarray` — Test whether values are gpuArray handles in MATLAB and RunMat.

tf = isgpuarray(x) returns true when x is a gpuArray handle and false for other value types, following MATLAB semantics.

Syntax

tf = isgpuarray(A)

Inputs

Name	Type	Required	Default	Description
`A`	`Any`	Yes	—	Input value to test.

Returns

Name	Type	Description
`tf`	`LogicalArray`	True when input is a gpuArray handle.

How `isgpuarray` works

gpuArray values return true without gathering device buffers.
Numeric, logical, complex, string, character, struct, cell, and object inputs return false.
The result is always a logical scalar.

Does RunMat run `isgpuarray` on the GPU?

The builtin only checks whether the value is a gpuArray handle. It never gathers device buffers or inspects the underlying data contents.

GPU memory and residency

RunMat keeps data on the GPU when a provider is active, and isgpuarray lets you verify residency boundaries in MATLAB-style code.

Examples

Checking a gpuArray handle

G = gpuArray(reshape(1:12, [3 4]));
tf = isgpuarray(G)

Expected output:

tf =
     1

Host arrays are not gpuArray values

A = [1 2 3];
tf = isgpuarray(A)

Expected output:

tf =
     0

Using `isgpuarray` with coding agents

Open a RunMat example with live inputs, then ask the agent to explain how isgpuarray changes the result.

Run a small isgpuarray example, explain the result, then change one input and compare the output.

FAQ

Does isgpuarray gather data back to the host?⌄

No. It inspects value metadata and returns a logical scalar without triggering a device transfer.

What happens if no acceleration provider is registered?⌄

isgpuarray still reports accurately for values that are already gpuArray handles. If a value is not a gpuArray handle, it returns false.

Tests

isfinite · isinf · islogical · isnan · isnumeric · isreal

Bit

and · not · or · xor

Rel

eq · ge · gt · isequal · le · lt · ne

Logical

logical

Open-source implementation

Unlike proprietary runtimes, every RunMat function is open-source. Read exactly how isgpuarray is executed, line by line, in Rust.

View the source for isgpuarray 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.
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isgpuarray — Test whether values are gpuArray handles in MATLAB and RunMat.