# step

**System object: **phased.RootMUSICEstimator

**Package: **phased

Perform DOA estimation

## Syntax

`ANG = step(H,X)`

ANG = step(H,X,ElAng)

## Description

**Note**

Starting in R2016b, instead of using the `step`

method
to perform the operation defined by the System object™, you can
call the object with arguments, as if it were a function. For example, ```
y
= step(obj,x)
```

and `y = obj(x)`

perform
equivalent operations.

`ANG = step(H,X)`

estimates the direction of arrivals (DOAs) from a signal
`X`

using the DOA estimator `H`

.
`X`

is a matrix whose columns correspond to the signal channels.
`ANG`

is a row vector of the estimated broadside angles (in
degrees). You can specify the argument `X`

as single or double
precision.

The size of the first dimension of the input matrix can vary to simulate a changing signal length. A size change can occur, for example, in the case of a pulse waveform with variable pulse repetition frequency.

`ANG = step(H,X,ElAng)`

specifies, in addition, the assumed elevation
angles of the signals. This syntax is only applicable when the
`SensorArray`

property of the object specifies a uniform circular
array (UCA). `ElAng`

is a scalar between -90° and 90° and
is applied to all signals. The elevation angles for all signals must be the same as
required by the *phase mode excitation* algorithm. You can specify
the argument `ElAng`

as single or double precision.

**Note**

The object performs an initialization the first time the object is executed. This
initialization locks nontunable properties
and input specifications, such as dimensions, complexity, and data type of the input data.
If you change a nontunable property or an input specification, the System object issues an error. To change nontunable properties or inputs, you must first
call the `release`

method to unlock the object.