GradeScale.java
package org.djunits.unit.scale;
/**
* A Scale for transforming a slope as a grade, where 45 degrees is 1, and 90 degrees is infinite, to radians. The formula is:
* angle = atan(grade). The factor that is given, is the factor by which the value is multiplied to get a grade. When a scale is
* constructed for e.g. ratio as a percentage (100% instead of 1), the conversionFactor to apply is 0.01.
* <p>
* Copyright (c) 2013-2024 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
* BSD-style license. See <a href="https://djunits.org/docs/license.html">DJUNITS License</a>.
* </p>
* @author <a href="https://www.tudelft.nl/averbraeck">Alexander Verbraeck</a>
* @author <a href="https://www.tudelft.nl/staff/p.knoppers/">Peter Knoppers</a>
*/
public class GradeScale implements Scale
{
/** */
private static final long serialVersionUID = 20151011L;
/** Multiply by this number to convert to the standard (e.g., SI) unit. */
private final double conversionFactorToGrade;
/**
* Construct a Scale for transforming a slope as a grade, where 45 degrees is 1, and 90 degrees is infinite, to radians.
* @param conversionFactorToGrade double; the conversion factor by which this number has to be multiplied to convert it to
* the standard (e.g., SI) unit.
*/
public GradeScale(final double conversionFactorToGrade)
{
this.conversionFactorToGrade = conversionFactorToGrade;
}
@Override
public final double toStandardUnit(final double value)
{
return Math.atan(value * this.conversionFactorToGrade);
}
@Override
public final double fromStandardUnit(final double value)
{
return Math.tan(value) / this.conversionFactorToGrade;
}
/**
* @return conversionFactorToGrade
*/
public final double getConversionFactorToGrade()
{
return this.conversionFactorToGrade;
}
@Override
public boolean isBaseSIScale()
{
return false;
}
@Override
public int hashCode()
{
final int prime = 31;
int result = 1;
long temp;
temp = Double.doubleToLongBits(this.conversionFactorToGrade);
result = prime * result + (int) (temp ^ (temp >>> 32));
return result;
}
@SuppressWarnings("checkstyle:needbraces")
@Override
public boolean equals(final Object obj)
{
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
GradeScale other = (GradeScale) obj;
if (Double.doubleToLongBits(this.conversionFactorToGrade) != Double.doubleToLongBits(other.conversionFactorToGrade))
return false;
return true;
}
@Override
public String toString()
{
return "GradeScale [conversionFactorToGrade=" + this.conversionFactorToGrade + "]";
}
}