dsp.Minimum

(To be removed) Find minimum values of input or sequence of inputs

Description

The dsp.Minimum object finds the minimum value of an input or sequence of inputs.

Note

The dsp.Minimum System object™ will be removed in a future release. To compute the minimum, use the min function. To compute the running minimum in MATLAB^®, use the dsp.MovingMinimum object. For more information, see Compatibility Considerations.

To compute the minimum value of an input or sequence of inputs:

Create the dsp.Minimum object and set its properties.
Call the object with arguments, as if it were a function.

To learn more about how System objects work, see What Are System Objects? (MATLAB).

Creation

Syntax

min = dsp.Minimum

min = dsp.Minimum(Name,Value)

Description

min = dsp.Minimum returns an object, min, that computes the value and/or index of the minimum elements in an input or a sequence of inputs over the specified Dimension.

min = dsp.Minimum(Name,Value) returns a minimum-finding object, min, with each specified property set to the specified value.

Properties

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Unless otherwise indicated, properties are nontunable, which means you cannot change their values after calling the object. Objects lock when you call them, and the release function unlocks them.

If a property is tunable, you can change its value at any time.

For more information on changing property values, see System Design in MATLAB Using System Objects (MATLAB).

`ValueOutputPort` — Output minimum value
`true` (default) | `false`

Set this property to true in order to output the minimum value of the input. Set this property to false in order to output the index of the minimum value of the input.

Dependencies

This property applies only when you set the RunningMinimum property to false.

`RunningMinimum` — Calculate over single input or multiple inputs
`false` (default) | `true`

When you set this property to true, the object computes the minimum value over successive calls to the object algorithm. When you set this property to false, the object computes the minimum value over the current input.

`IndexOutputPort` — Output index of minimum value
`true` (default) | `false`

Set this property to true to output the index of the minimum value of the input.

Dependencies

This property applies only when you set the RunningMinimum property to false.

`ResetInputPort` — Additional input to enable resetting of running minimum
`false` (default) | `true`

Set this property to true to enable resetting of the running minimum. When you set this property to true, you must specify a reset input argument to the object to reset the running minimum. This property applies only when you set the RunningMinimum property to true.

`ResetCondition` — Condition that triggers resetting of running minimum
`Non-zero` (default) | `Rising edge` | `Falling edge` | `Either edge`

Specify the event that resets the running minimum. This property applies only when you set the ResetInputPort property to true.

`IndexBase` — Numbering base for index of minimum value
`One` (default) | `Zero`

Specify the numbering used when computing the index of the minimum value as starting from either One or Zero.

Dependencies

This property applies only when you set the IndexOutputPort property to true.

`Dimension` — Dimension to operate along
`Column` (default) | `All` | `Row` | `Custom`

Specify how the minimum calculation is performed over the data.

Dependencies

This property applies when you set the RunningMinimum property to false.

`CustomDimension` — Numerical dimension to calculate over
`1` (default) | positive integer

Specify the integer dimension of the input signal over which the object finds the minimum. The cannot exceed the number of dimensions in the input signal.

Dependencies

This property only applies when you set the Dimension property to Custom.

Fixed-Point Properties

`RoundingMethod` — Rounding method for fixed-point operations
`Floor` (default) | `Ceiling` | `Convergent` | `Nearest` | `Round` | `Simplest` | `Zero`

Specify the rounding method.

`OverflowAction` — Action to take when integer input is out-of-range
`Wrap` (default) | `Saturate`

Specify the overflow action.

`ProductDataType` — Data type of product
`Same as input` (default) | `Custom`

Specify the product fixed-point data type.

`CustomProductDataType` — Product word and fraction lengths
`numerictype([],32,30)` (default) | numerictype

Specify the product fixed-point type as a scaled numerictype object with a Signedness of Auto.

Dependencies

This property applies only when you set the AccumulatorDataType property to Custom.

`AccumulatorDataType` — Data type of accumulator
`Same as product` (default) | `Same as input` | `Custom`

Specify the accumulator fixed-point data type as one of | Same as product | Same as input | Custom |.

`CustomAccumulatorDataType` — Accumulator word and fraction lengths
`numerictype([],32,30)` (default) | numerictype

Specify the accumulator fixed-point type as a scaled numerictype object with a Signedness of Auto.

Dependencies

This property applies only when you set the AccumulatorDataType property to Custom.

Usage

Syntax

[val,ind] = min(x)

val = min(x)

ind = min(x)

val = min(x,r)

Description

[val,ind] = min(x) returns the minimum value, val, and the index or position of the minimum value, ind, along the specified Dimension of x.

val = min(x) returns the minimum value, val, of the input x. When the RunningMinimum property is true, val corresponds to the minimum value over successive calls to the algorithm.

ind = min(x) returns the zero- or one-based index ind of the minimum value when the IndexOutputPort property is true and the ValueOutputPort property is false. You must set the RunningMinimum property to false to use this syntax.

val = min(x,r) resets the state of min based on the value of reset signal, r, and the ResetCondition property. To enable this type of processing, set the RunningMinimum property to true and the ResetInputPort property to true.

Input Arguments

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`x` — Data input
vector | matrix

Data input, specified as a vector or a matrix. If x is a matrix, each column is treated as an independent channel. The minimum is determined along each channel. The object also accepts variable-size inputs. Once the object is locked, you can change the size of each input channel.

`r` — Reset signal
scalar

Reset signal used to reset the running minimum, specified as a scalar value. The object resets the running minimum if the reset signal satisfies the ResetCondition.

Dependencies

To enable this signal, set the RunningMinimum property to true and the ResetInputPort property to true.

Output Arguments

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`val` — Minimum value of input
scalar | vector

Minimum value of the input, returned as a scalar or a vector. The object determines the minimum value of the input along each channel. If the input is a column vector, the output is a scalar. If the input is a multichannel signal, the output signal is a 1-by-N vector, where N is the number of input channels.

`ind` — Index of minimum
scalar | vector

Indices of the minimum values of the input, returned as a scalar or a vector. The object determines the indices of the minimum values of the input along each channel. If the input is a column vector, the output is a scalar. If the input is a multichannel signal, the output signal is a 1-by-N vector, where N is the number of input channels.

Data Types: double | uint32

Object Functions

To use an object function, specify the System object as the first input argument. For example, to release system resources of a System object named obj, use this syntax:

release(obj)

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Common to All System Objects

`step`	Run System object algorithm
`release`	Release resources and allow changes to System object property values and input characteristics
`reset`	Reset internal states of System object

Examples

Compute Minimum and Running Minimum of Signal

Note: If you are using R2016a or an earlier release, replace each call to the object with the equivalent step syntax. For example, obj(x) becomes step(obj,x).

Find a minimum value and its index.

 min1 = dsp.Minimum;
 x = randn(100,1);
 [y, I] = min1(x) %#ok

y = -2.9443

I = 35

Compute a running minimum.

 min2 = dsp.Minimum;
 min2.RunningMinimum = true;
 x = randn(100,1);
 y = min2(x); 
 plot(y);

y(i) is the minimum of all values in the vector x(1:i).

Algorithms

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

Compatibility Considerations

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`dsp.Minimum` System object will be removed

Warns starting in R2019b

The dsp.Minimum System object will be removed in a future release. To compute the minimum, use the min function. To compute the running minimum, use the dsp.MovingMinimum object.

Update Code

This table shows typical usage of the System object and explains how to update existing code to use the equivalent function.

Discouraged Usage Recommended Replacement

Discouraged Usage	Recommended Replacement
Minimum Min1 = dsp.Minimum; x = randn(100,1); y = Min1(x); Running Minimum Min2 = dsp.Minimum; Min2.RunningMinimum = true; x = randn(100,1); y = Min2(x); % Running minimum If you are using a release prior to R2016b, replace `Min1(x)` with `step(Min1,x)` and `Min2(x)` with `step(Min2,x)`.	Minimum x = randn(100,1); y = min(x); Running Minimum mvgMin = dsp.MovingMinimum; mvgMin.SpecifyWindowLength = false; x = randn(100,1); y = mvgMin(x);

Minimum

Min1 = dsp.Minimum;
x = randn(100,1);
y = Min1(x);

Running Minimum

Min2 = dsp.Minimum;
Min2.RunningMinimum = true;
x = randn(100,1);
y = Min2(x); % Running minimum

If you are using a release prior to R2016b, replace Min1(x) with step(Min1,x) and Min2(x) with step(Min2,x).

Minimum

x = randn(100,1);
y = min(x);

Running Minimum

mvgMin = dsp.MovingMinimum;
mvgMin.SpecifyWindowLength = false;
x = randn(100,1);
y = mvgMin(x);

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

See System Objects in MATLAB Code Generation (MATLAB Coder).

Documentation

dsp.Minimum

Description

Note

Creation

Syntax

Description

Properties

ValueOutputPort — Output minimum value true (default) | false

Dependencies

RunningMinimum — Calculate over single input or multiple inputs false (default) | true

IndexOutputPort — Output index of minimum value true (default) | false

Dependencies

ResetInputPort — Additional input to enable resetting of running minimum false (default) | true

ResetCondition — Condition that triggers resetting of running minimum Non-zero (default) | Rising edge | Falling edge | Either edge

IndexBase — Numbering base for index of minimum value One (default) | Zero

Dependencies

Dimension — Dimension to operate along Column (default) | All | Row | Custom

Dependencies

CustomDimension — Numerical dimension to calculate over 1 (default) | positive integer

Dependencies

Fixed-Point Properties

RoundingMethod — Rounding method for fixed-point operations Floor (default) | Ceiling | Convergent | Nearest | Round | Simplest | Zero

OverflowAction — Action to take when integer input is out-of-range Wrap (default) | Saturate

ProductDataType — Data type of product Same as input (default) | Custom

CustomProductDataType — Product word and fraction lengths numerictype([],32,30) (default) | numerictype

Dependencies

AccumulatorDataType — Data type of accumulator Same as product (default) | Same as input | Custom

CustomAccumulatorDataType — Accumulator word and fraction lengths numerictype([],32,30) (default) | numerictype

Dependencies

Usage

Syntax

Description

Input Arguments

x — Data input vector | matrix

r — Reset signal scalar

Dependencies

Output Arguments

val — Minimum value of input scalar | vector

ind — Index of minimum scalar | vector

Object Functions

Common to All System Objects

Examples

Compute Minimum and Running Minimum of Signal

Algorithms

Compatibility Considerations

dsp.Minimum System object will be removed

Extended Capabilities

C/C++ Code Generation Generate C and C++ code using MATLAB® Coder™.

See Also

Functions

Objects

Blocks

Introduced in R2012a

DSP System Toolbox Documentation

Support

`ValueOutputPort` — Output minimum value
`true` (default) | `false`

`RunningMinimum` — Calculate over single input or multiple inputs
`false` (default) | `true`

`IndexOutputPort` — Output index of minimum value
`true` (default) | `false`

`ResetInputPort` — Additional input to enable resetting of running minimum
`false` (default) | `true`

`ResetCondition` — Condition that triggers resetting of running minimum
`Non-zero` (default) | `Rising edge` | `Falling edge` | `Either edge`

`IndexBase` — Numbering base for index of minimum value
`One` (default) | `Zero`

`Dimension` — Dimension to operate along
`Column` (default) | `All` | `Row` | `Custom`

`CustomDimension` — Numerical dimension to calculate over
`1` (default) | positive integer

`RoundingMethod` — Rounding method for fixed-point operations
`Floor` (default) | `Ceiling` | `Convergent` | `Nearest` | `Round` | `Simplest` | `Zero`

`OverflowAction` — Action to take when integer input is out-of-range
`Wrap` (default) | `Saturate`

`ProductDataType` — Data type of product
`Same as input` (default) | `Custom`

`CustomProductDataType` — Product word and fraction lengths
`numerictype([],32,30)` (default) | numerictype

`AccumulatorDataType` — Data type of accumulator
`Same as product` (default) | `Same as input` | `Custom`

`CustomAccumulatorDataType` — Accumulator word and fraction lengths
`numerictype([],32,30)` (default) | numerictype

`x` — Data input
vector | matrix

`r` — Reset signal
scalar

`val` — Minimum value of input
scalar | vector

`ind` — Index of minimum
scalar | vector

`dsp.Minimum` System object will be removed

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.