Documentation

MinMax

Output minimum or maximum input value

Library

Math Operations

Description

The MinMax block outputs either the minimum or the maximum element or elements of the inputs. You can choose the function to apply by selecting one of the choices from the Function parameter list.

If the block has one input port, the input must be a scalar or a vector. The block outputs a scalar equal to the minimum or maximum element of the input vector.

If the block has multiple input ports, all nonscalar inputs must have the same dimensions. The block expands any scalar inputs to have the same dimensions as the nonscalar inputs. The block outputs a signal having the same dimensions as the input. Each output element equals the minimum or maximum of the corresponding input elements.

The MinMax block ignores any input value that is NaN, except when every input value is NaN. When all input values are NaN, the output is NaN, either as a scalar or the value of each output vector element.

Data Type Support

The MinMax block accepts and outputs real signals of the following data types:

  • Floating point

  • Built-in integer

  • Fixed point

For more information, see Data Types Supported by Simulink in the Simulink® documentation.

Parameters and Dialog Box

The Main pane of the MinMax block dialog box appears as follows:

Function

Specify whether to apply the function min or max to the input.

Number of input ports

Specify the number of inputs to the block.

Enable zero-crossing detection

Select to enable zero-crossing detection. For more information, see Zero-Crossing Detection.

Sample time (-1 for inherited)

Specify the time interval between samples. To inherit the sample time, set this parameter to -1. See Specify Sample Time in the online documentation for more information.

The Signal Attributes pane of the MinMax block dialog box appears as follows:

Require all inputs to have the same data type

Select this check box to require that all inputs have the same data type.

Output minimum

Specify the minimum value that the block should output. The default value is [] (unspecified). Simulink software uses this value to perform:

  • Simulation range checking (see Signal Ranges)

  • Automatic scaling of fixed-point data types

Output maximum

Specify the maximum value that the block should output. The default value is[] (unspecified). Simulink software uses this value to perform:

  • Simulation range checking (see Signal Ranges)

  • Automatic scaling of fixed-point data types

Output data type

Specify the output data type. You can set it to:

  • A rule that inherits a data type, for example, Inherit: Inherit via back propagation

  • The name of a built-in data type, for example, single

  • The name of a data type object, for example, a Simulink.NumericType object

  • An expression that evaluates to a data type, for example, fixdt(1,16,0)

Click the Show data type assistant button to display the Data Type Assistant, which helps you set the Output data type parameter.

See Specify Block Output Data Types for more information.

Lock output data type setting against changes by the fixed-point tools

Select to lock the output data type setting of this block against changes by the Fixed-Point Tool and the Fixed-Point Advisor. For more information, see Use Lock Output Data Type Setting.

Integer rounding mode

Specify the rounding mode for fixed-point operations. For more information, see Rounding. in the Fixed-Point Designer™ documentation.

Saturate on integer overflow
ActionReasons for Taking This ActionWhat Happens for OverflowsExample

Select this check box.

Your model has possible overflow, and you want explicit saturation protection in the generated code.

Overflows saturate to either the minimum or maximum value that the data type can represent.

The maximum value that the int8 (signed, 8-bit integer) data type can represent is 127. Any block operation result greater than this maximum value causes overflow of the 8-bit integer. With the check box selected, the block output saturates at 127. Similarly, the block output saturates at a minimum output value of -128.

Do not select this check box.

You want to optimize efficiency of your generated code.

You want to avoid overspecifying how a block handles out-of-range signals. For more information, see Checking for Signal Range Errors.

Overflows wrap to the appropriate value that is representable by the data type.

The maximum value that the int8 (signed, 8-bit integer) data type can represent is 127. Any block operation result greater than this maximum value causes overflow of the 8-bit integer. With the check box cleared, the software interprets the overflow-causing value as int8, which can produce an unintended result. For example, a block result of 130 (binary 1000 0010) expressed as int8, is -126.

When you select this check box, saturation applies to every internal operation on the block, not just the output or result. Usually, the code generation process can detect when overflow is not possible. In this case, the code generator does not produce saturation code.

Examples

The sldemo_fuelsyssldemo_fuelsys model shows how to use the MinMax block.

In the Engine Gas Dynamics/Throttle & Manifold/Throttle subsystem, the MinMax block uses the min operator:

In the Engine Gas Dynamics/Mixing & Combustion subsystem, the MinMax block uses the max operator:

For more information, see the model descriptionmodel description.

Characteristics

Direct Feedthrough

Yes

Sample Time

Specified in the Sample time parameter

Scalar Expansion

Yes, of the inputs

Dimensionalized

Yes

Multidimensionalized

Yes

Zero-Crossing Detection

Yes, if enabled

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