You are here: Start » Filter Reference » Shape Features » ShapeMoment
Computes the selected second-order moment of a shape in regular and normalized ( divided by shape area ) variant.
Name | Type | Description | |
---|---|---|---|
inShape | Path | ||
inMomentType | ShapeMomentType | ||
inCentral | Bool | ||
outMoment | Real | ||
outNormMoment | Real |
Description
The operation computes the mathematical features of a shape called moments. Those are integrals computed as follows:
\[ \begin{aligned} Moment_{2,0}(S) &= \int_{S} p_x^2 \\ Moment_{1,1}(S) &= \int_{S} p_x p_y \\ Moment_{0,2}(S) &= \int_{S} p_y^2 \end{aligned} \]The integration is conducted over shape surface, while \( p_x \) and \( p_y \) denote, accordingly, x and y coordinate of a point.
When inCentral parameter is set, the shape is shifted before computations so that its mass center is at location (0,0).
Note that if the input path is not a valid shape (i.e. it has at least one self-intersection), the computation may lead to results that are not intuitive.
Errors
This filter can throw an exception to report error. Read how to deal with errors here: Error Handling
Error type | Description |
---|---|
DomainError | Open path on input in ShapeMoment. |
DomainError | Not supported moment type in ShapeMoment. |
Complexity Level
This filter is available on Basic Complexity Level.