Accelerating the pace of engineering and science

# Documentation Center

• Trials
• Product Updates

# dsp.UpperTriangularSolver System object

Package: dsp

Solve upper-triangular matrix equation

## Description

The UpperTriangularSolver object solves UX = B for X when U is a square, upper-triangular matrix with the same number of rows as B.

To solve UX = B:

1. Define and set up your linear system solver. See Construction.

2. Call step to solve the equation according to the properties of dsp.UpperTriangularSolver. The behavior of step is specific to each object in the toolbox.

## Construction

H = dsp.UpperTriangularSolver returns a linear system solver, H, used to solve UX = B where U is an upper (or unit-upper) triangular matrix.

H = dsp.UpperTriangularSolver('PropertyName',PropertyValue,...) returns a linear system solver, H, with each specified property set to the specified value.

## Properties

 OverwriteDiagonal Replace diagonal elements of input with ones When you set this property to true, the linear system solver replaces the elements on the diagonal of the input, U, with ones. Set this property to either true or false. The default is false. RealDiagonalElements Indicate that diagonal of complex input is real When you set this property to true, the linear system solver optimizes computation speed if the diagonal elements of complex input, U, are real. This property applies only when you set the OverwriteDiagonal property to false. Set this property to either true or false. The default is false.

## Methods

 clone Create upper triangular solver object with same property values getNumInputs Number of expected inputs to step method getNumOutputs Number of outputs of step method isLocked Locked status for input attributes and nontunable properties release Allow property value and input characteristics changes step Solve matrix equation for specified inputs

## Examples

Solve an upper-triangular matrix equation:

``` huptriang = dsp.UpperTriangularSolver;
u = triu(rand(4, 4));
b = rand(4, 1);
% Check that result is the solution to the linear
% equations.
x1 = inv(u)*b
x = step(huptriang, u, b)

```

## Algorithms

This object implements the algorithm, inputs, and outputs described on the Backward Substitution block reference page. The object properties correspond to the block parameters.

## See Also

Was this topic helpful?