Classification using expression

Use expressions to calculate properties of individual classes in a category.

The last Expression can be TRUE which will imply that the last expression will always be assigned if all above evaluates as false

Parameters

Expression

NOTE The expressions are applied in order top-down

Choose a new class and write the expression for it.

Click the “Add” button to add additional classification expressions. Click the color square to select color for the classification class.

The operators that can be used:

Standard arithmetic (+,-,/,* …) and comparison operators (=,>,< …) as well as some mathematical expressions (…) and constant values () can be used in expressions.

Expand to see all available operator

Arithmetic Operator	Description
`-`	Subtract
`+`	Add
`/`	Divide
`*`	Multiply
`%`	Modulo
`^`	Raised to a power

Comparison Operator	Description
`=`	Equal to
`\|` `OR`	TRUE if any of the conditions separated by OR is TRUE
`&` `AND`	TRUE if all the conditions separated by AND is TRUE
`!=` `<>`	Not equal to
`<`	Less than
`<=`	Less than or equal to
`>`	Greater than
`>=`	Greater than or equal to

Function operator	Description
`SQRT(N)`
`SIN(N)`
`COS(N)`
`EXP(N)`
`LOG(N)`
`LOG10(N)`
`AVG(N)`
`ROUND(N)`

Constants	Description
`TRUE`	Always evaluates to TRUE
`FALSE`	Always evaluates to FALSE
`INF`	token value
`PI`	approximated to 3.14159

The parameters that can be used:

Area
Length
Width
Circumference
Regularity
Roundness
Angle
D1
D2
X
Y
MaxBorderDistance
BoundingBoxArea

For details on each available property see: Object properties Details

Pretreatments

In top-down applied order ⬇️ , meaning Savitzky-Golay is applied first then Derivative and so on.

Savitzky-Golay
Derivative
SNV (Standard Normal Variate)
Logarithm
Center
UV (Unit Variance) scaling

For more on each type of pretreatment see: Pretreatments