getPrevious, prev

Previous value of data in Requirements Table block

Since R2022a

Syntax

z = getPrevious(u)

z = prev(u)

Description

z = getPrevious(u) returns the value of the data at the previous time step. This operator works only in the Requirements Table block.

z = prev(u) is an alternative way to execute getPrevious(u).

Input Arguments

u — Data

block data

Data, specified as data defined in the Requirements Table block. u must be input or output data. You must specify an initial value for u in the Property Inspector. For more information, see Define Data in Requirements Table Blocks.

Output Arguments

z — Value at previous time step

any data type, depending on the input

Value at the previous time step, returned as a value with the same data type of u.

Examples

Check Previous Data Values

At the start time, set y equal to 0. After the start time, recall the value of the input data u in the precondition at the previous time step. One requirement checks if the previous value of u is greater than or equal to the current value, and another checks if the previous value is less than the current value. The block assigns different values for the output data y.

Tips

• You can use this operator only in the Requirements tab.

Version History

Introduced in R2022a