org.opengis.geometry

Interface Precision

All Superinterfaces:

Comparable<Precision>

public interface Precision
extends Comparable<Precision>

Specifies the precision model of the direct positions in a geometry.

A precision model defines a grid of allowable points. The round(org.opengis.geometry.DirectPosition) method allows to round a direct position to the nearest allowed point. The getType() method describes the collapsing behavior of a direct position.

Precision instances can be sorted by their scale.

Since:

GeoAPI 2.1

Author:

Jody Garnett

Method Summary

Modifier and Type	Method and Description
int	compareTo(Precision other) Compares this precision model with the specified one.
double	getScale() Multiplying factor used to obtain a precise ordinate.
PrecisionType	getType() Returns the type of this precision model.
void	round(DirectPosition position) Rounds a direct position to this precision model in place.

Method Detail

compareTo

int compareTo(Precision other)

Compares this precision model with the specified one. Returns -1 is this model is less accurate than the other one, +1 if it is more accurate, or 0 if they have the same accuracy.

Specified by:

compareTo in interface Comparable<Precision>

Parameters:

other - Other precision model to compare against.

Returns:

a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the other.

getScale

double getScale()

Multiplying factor used to obtain a precise ordinate.

Multiply by this value and then divide by this value to round correctly:

 double scale = pm.getScale();
 return Math.round(value * scale) / scale;
 

So to round to 3 significant digits we would have a scale of 1000. Tip: the number of significant digits can be computed as below:

 int significantDigits = (int) Math.ceil(Math.log10(pm.getScale()));
 

Returns:

Multiplying factor used before rounding.

getType

PrecisionType getType()

Returns the type of this precision model.

round

void round(DirectPosition position)

Rounds a direct position to this precision model in place.

It is likely that a Precision instance will keep different rounding rules for different axis (example x & y ordinates may be handled differently then height), by always rounding a direct position as a whole we will enable this functionality.