isnumeric — Test numeric storage type in MATLAB and RunMat.

tf = isnumeric(x) returns true when x stores numeric data (real or complex) and false otherwise. Classification behavior follows MATLAB semantics.

Syntax

tf = isnumeric(A)

Inputs

Returns

Errors

How isnumeric works

• Every built-in numeric class (double, single, signed/unsigned integer types) returns true, including complex scalars.
• Real and complex numeric arrays return true regardless of dimensionality or residency on the CPU or GPU.
• gpuArray values rely on provider metadata: numeric handles return true, while logical masks constructed on the GPU return false.
• Logical values, characters, strings, tables, cell arrays, structs, objects, and function handles return false.
• The result is always a logical scalar.

Does RunMat run isnumeric on the GPU?

When RunMat Accelerate is active, isnumeric first checks provider metadata via the logical_islogical hook to determine whether a gpuArray handle was created as a logical mask. Providers that supply the hook can answer the query without copying data back to the host. When the hook is absent, RunMat consults its residency metadata and only gathers the value to host memory when the residency tag is missing, ensuring the builtin always succeeds.

GPU memory and residency

You generally do not need to call gpuArray manually. RunMat's auto-offload planner keeps numeric tensors on the GPU across fused expressions whenever that improves performance. Explicit gpuArray and gather calls remain available for compatibility with MATLAB scripts that manage residency themselves.

Examples

Checking if a scalar double is numeric

tf = isnumeric(42)

Expected output:

tf =
     1

Detecting numeric matrices

A = [1 2 3; 4 5 6];
tf = isnumeric(A)

Expected output:

tf =
     1

Testing complex numbers for numeric storage

z = 1 + 2i;
tf = isnumeric(z)

Expected output:

tf =
     1

Logical arrays are not numeric

mask = logical([1 0 1]);
tf = isnumeric(mask)

Expected output:

tf =
     0

Character vectors and strings return false

chars = ['R' 'u' 'n'];
name = "RunMat";
tf_chars = isnumeric(chars);
tf_string = isnumeric(name)

Expected output:

tf_chars =
     0

tf_string =
     0

Evaluating gpuArray inputs

G = gpuArray(rand(4));
mask = G > 0.5;
tf_numeric = isnumeric(G);
tf_mask = isnumeric(mask)

Expected output:

tf_numeric =
     1

tf_mask =
     0

Using isnumeric with coding agents

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

FAQ

Related Logical functions

Open-source implementation

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

• View the source for isnumeric in Rust on GitHub
• Learn how the RunMat runtime works
• Found a bug? Open an issue with a minimal reproduction.

About RunMat

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