step — Compute or plot the step response of a SISO transfer-function model.

step(sys) plots the unit-step response of a SISO transfer-function object created by tf. [y, tOut] = step(sys) returns sampled response data and the time vector. step(sys, tFinal) uses a scalar final time, while step(sys, t) evaluates at an explicit time vector.

Syntax

step(sys)
y = step(sys)
[y, tOut] = step(sys)
[y, tOut] = step(sys, tFinal)
[y, tOut] = step(sys, t)

• sys must be a SISO tf object.
• tFinal is a positive finite scalar final time.
• t is a finite, nonnegative, nondecreasing numeric time vector.

How step works

• Supports SISO tf objects with real coefficients.
• Returns the response y as a column vector for single-output calls.
• Returns [y, tOut] for two-output calls.
• Plots the response for no-output calls.
• Chooses an automatic time vector when no time input is supplied.
• Accepts a positive finite scalar final time.
• Accepts a finite, nonnegative, nondecreasing explicit time vector.
• Discrete-time models use the stored Ts sample time.

GPU memory and residency

step computes on the host from tf metadata and returns host tensors.

Examples

Returning response data for a first-order system

sys = tf(1, [1 1]);
[y, t] = step(sys);

Expected output:

y and t are column vectors.

Using a scalar final time

sys = tf(1, [1 1]);
[y, t] = step(sys, 5);

Expected output:

t(end) = 5

Using an explicit time vector

sys = tf(1, [1 1]);
t = 0:0.5:2;
y = step(sys, t);

Expected output:

y is sampled at the values in t.

Plotting the step response

sys = tf(1, [1 1]);
step(sys);

Expected output:

A step-response plot is rendered.

How RunMat validates step

step validates object class, coefficient type, properness, sample time, and time-vector inputs before simulation. Unit and integration tests cover first-order response values, scalar final time, explicit vectors, discrete sample-time behavior, multi-output ordering, and VM dispatch.

• Implementation: `crates/runmat-runtime/src/builtins/control/step.rs`

See Correctness & Trust for the full methodology and coverage table.

FAQ

Related Control functions

Open-source implementation

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

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

About RunMat

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