## Class SloppyMath

• ```public class SloppyMath
extends Object```
Math functions that trade off accuracy for speed.
• ### Constructor Summary

Constructors
Constructor Description
`SloppyMath()`
• ### Method Summary

All Methods
Modifier and Type Method Description
`static double` `asin​(double a)`
Returns the arc sine of a value.
`static double` `cos​(double a)`
Returns the trigonometric cosine of an angle.
`static double` `haversinMeters​(double sortKey)`
Returns the Haversine distance in meters between two points given the previous result from `haversinSortKey(double, double, double, double)`
`static double` ```haversinMeters​(double lat1, double lon1, double lat2, double lon2)```
Returns the Haversine distance in meters between two points specified in decimal degrees (latitude/longitude).
`static double` ```haversinSortKey​(double lat1, double lon1, double lat2, double lon2)```
Returns a sort key for distance.
• ### Methods inherited from class java.lang.Object

`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`
• ### Constructor Detail

• #### SloppyMath

`public SloppyMath()`
• ### Method Detail

• #### haversinMeters

```public static double haversinMeters​(double lat1,
double lon1,
double lat2,
double lon2)```
Returns the Haversine distance in meters between two points specified in decimal degrees (latitude/longitude). This works correctly even if the dateline is between the two points.

Error is at most 4E-1 (40cm) from the actual haversine distance, but is typically much smaller for reasonable distances: around 1E-5 (0.01mm) for distances less than 1000km.

Parameters:
`lat1` - Latitude of the first point.
`lon1` - Longitude of the first point.
`lat2` - Latitude of the second point.
`lon2` - Longitude of the second point.
Returns:
distance in meters.
• #### cos

`public static double cos​(double a)`
Returns the trigonometric cosine of an angle.

Error is around 1E-15.

Special cases:

• If the argument is `NaN` or an infinity, then the result is `NaN`.
Parameters:
`a` - an angle, in radians.
Returns:
the cosine of the argument.
`Math.cos(double)`
• #### asin

`public static double asin​(double a)`
Returns the arc sine of a value.

The returned angle is in the range -pi/2 through pi/2. Error is around 1E-7.

Special cases:

• If the argument is `NaN` or its absolute value is greater than 1, then the result is `NaN`.
Parameters:
`a` - the value whose arc sine is to be returned.
Returns:
arc sine of the argument
`Math.asin(double)`