erf — Compute error-function values element-wise in MATLAB and RunMat.

Y = erf(X) evaluates the Gaussian error function element-by-element for real numeric input. RunMat follows MATLAB's documented real, nonsparse surface and keeps real GPU tensors resident when the active provider supports unary_erf.

Syntax

Y = erf(X)

Inputs

Returns

Errors

How erf works

• erf(X) applies the error function element-by-element while preserving the input tensor shape.
• Double inputs return double results; single tensors preserve single dtype metadata with single-rounded output values.
• Scalar integer, logical, and character inputs are promoted through RunMat's ordinary numeric coercion path for compatibility with existing elementwise builtins.
• Complex, string, and sparse inputs produce stable RunMat:erf:InvalidInput errors.
• Real GPU tensors stay on device when the provider implements unary_erf; otherwise RunMat gathers the tensor, evaluates on the host, and returns a host value with the computed results.

GPU memory and residency

Yes when the active provider implements unary_erf for real-valued gpuArray inputs. Providers without that hook trigger a host fallback, so the computed result is returned as a host tensor rather than a resident gpuArray.

Examples

Calculate the error function of a scalar

y = erf(1)

Expected output:

y = 0.8427

Apply erf to every element of a vector

x = [-0.5 0 1 3];
y = erf(x)

Expected output:

y = [-0.5205 0 0.8427 1.0000]

Evaluate a matrix element-wise

A = [0.29 -0.11; 3.1 -2.9];
B = erf(A)

Expected output:

B = [0.3183 -0.1236; 1.0000 -1.0000]

Use erf when computing a normal CDF

x = -3:0.1:3;
y = 0.5*(1 + erf(x/sqrt(2)));

Expected output:

y = 1x61 double

Run erf on GPU data

G = gpuArray([-1 0 1]);
out = erf(G);
result = gather(out)

Expected output:

result = [-0.8427 0 0.8427]

Using erf with coding agents

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

FAQ

Related Math functions

About RunMat

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