zero — Return zeros of SISO transfer-function models.

zero(sys) returns the roots of the numerator polynomial for a supported SISO tf model.

Syntax

z = zero(sys)

• sys must be a SISO tf object.

How zero works

• Supports SISO tf objects.
• Returns an N x 1 real vector when all zeros are real.
• Returns an N x 1 complex vector when any zero has a nonzero imaginary part.
• Static-gain models return an empty zero vector.
• ss transmission zeros are not implemented yet; use tf models for this builtin.

GPU memory and residency

zero returns host-resident vectors.

Example

Second-order zeros

H = tf([1 3 2], [1 4]);
zero(H)

Expected output:

ans = [-1; -2]

How RunMat validates zero

zero validates the input model and computes numerator roots through the shared control polynomial root path. Tests cover real, complex-conjugate, and static-gain zero vectors plus VM integration.

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

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

Using zero with coding agents

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

FAQ

Related Control functions

Open-source implementation

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

• View the source for zero 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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