Contents

Index

• Getting Started

• User Guide

• Functions

• GUIs

• Linear Models

• Data Extraction

• Conversions

• System Interconnections

• System Gain and Dynamics

• Time Domain Analysis

• Frequency Domain Analysis

• Model Simplification

• Compensator Design

• LQR/LQG Design

• State-Space Models

• Frequency Response Data Models

• Time Delays

• Model Dimensions and Characteristics

• Overloaded and Arithmetic Operators

• Matrix Equation Solvers

• Preferences

• Visualization of Model Dynamics and Responses

• Plot Customization

• Help

• Blocks

Examples

• Release Notes

Learn more about Control System Toolbox

dcgain - Low-frequency (DC) gain of LTI system

Syntax

k = dcgain(sys)

Description

k = dcgain(sys) computes the DC gain k of the LTI model sys.

Continuous Time

The continuous-time DC gain is the transfer function value at the frequency . For state-space models with matrices , this value is

Discrete Time

The discrete-time DC gain is the transfer function value at . For state-space models with matrices , this value is

Remark

The DC gain is infinite for systems with integrators.

Example

To compute the DC gain of the MIMO transfer function

type

H = [1 tf([1 -1],[1 1 3]) ; tf(1,[1 1]) tf([1 2],[1 -3])]
dcgain(H)
ans =
    1.0000   -0.3333
    1.0000   -0.6667