# dcgain

Low-frequency (DC) gain of a state-space or transfer function model

## Syntax

K = dcgain(SYS)

K = dcgain(NUM, DEN)

K = dcgain(A, B, C, D)

## Inputs

SYS
Continuous-time state-space or transfer function model.
NUM
The numerator polynomial coefficient vector or matrix.
DEN
The denominator polynomial coefficient vector.
A
The state matrix (n x n), where n is the number of states.
B
The input matrix (n x p), where p is the number of inputs.
C
The output matrix (q x n), where q is the number of outputs.
D
The direct transmission matrix (q x p).

## Outputs

K
The gain scalar or matrix.

## Examples

State space model input:
[a, b, c, d] = ord2(2.4,0.4)
sys = ss(a, b, c, d)
r = dcgain(sys)
r = 0.173611111
Transfer function model input:
k = dcgain([1],[1 5 6 2])
k = 0.5