isgpuarray — Return true when a value is stored as a gpuArray handle.

tf = isgpuarray(x) returns a logical scalar that is true when x is a gpuArray handle. All other value kinds, including numeric arrays, logical arrays, characters, structs, and objects, return false.

How isgpuarray works in RunMat

• 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.

How isgpuarray runs 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

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.

Related functions to explore

These functions work well alongside isgpuarray. Each page has runnable examples you can try in the browser.

gpuArray, gather, islogical, isa, isfinite, isinf, isnan, isnumeric, isreal

Open-source implementation

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

• View isgpuarray.rs on GitHub
• Learn how the runtime works
• Found a bug? Open an issue with a minimal reproduction.

About RunMat

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• Simulations that took hours now take minutes. RunMat automatically optimizes your math for GPU execution on Apple, Nvidia, and AMD hardware. No code changes needed.
• Start running code in seconds. Open the browser sandbox or download a single binary. No license server, no IT ticket, no setup.
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