# Java Summary: Math Class

Some basic math functions can be found in the Math class. The `StrictMath` class (not described here) may produce less accurate results and be slower, but will produce absolutely identical results, bit for bit, on all machines. Don't use `StrictMath` unless you need this very specific kind of portability.

If you need numbers that exceed the range of `long`, use `java.math.BigInteger`. If you need to do exact decimal arithmetic, use `java.math.BigDecimal`, which gives complete control over precision and rounding, eg for financial calculations. Assume following declarations

```float f;
double d, d1, d2;
double ar;  // angle in radians.
x is any of int, long, float, or double.```
 Math Constants Two common constants are defined in the Math class. double Math.E() Value of e, 2.718282..., base of the natural logarithms. double Math.PI() Value of pi, 3.14159265 .... Math Methods Trigonometric Methods All trigonometric method parameters are measured in radians, the normal mathematical system of angles, and not in degrees, the normal human angular measurement system. Use the toRadians or toDegrees methods to convert between these systems, or use the fact that there are 2*PI radians in 360 degrees. In addition to the methods below, the arc methods are also available. double Math.sin(ar) Returns the sine of ar. double Math.cos(ar) Returns the cosine of ar. double Math.tan(ar) Returns the tangent of ar. double Math.toRadians(d) Returns d (angle in degrees) converted to radians. double Math.toDegrees(ar) Returns ar (angle in radians) converted to degrees. Exponential Methods The two basic functions for logarithms and power are available. These both use the base e (Math.E) as is the usual case in mathematics. double Math.exp(d) Returns e (2.71...) to the power d. double Math.pow(d1, d2) Returns d1d2. double Math.log(d) Returns the logarithm of d to base e. double Math.log10(d) Returns the logarithm of d to base 10. Misc Methods double Math.sqrt(d) Returns the square root of d. t Math.abs(x) Returns absolute value of x with same type as the parameter: int, long, float, or double. t Math.max(x, y) Returns maximum of x and y with same type as the parameter: int, long, float, or double. t Math.min(x, y) Returns minimum of x and y with same type as the parameter: int, long, float, or double. Integer Related Methods The following methods translate floating point values to integer values, altho these values may still be stored in a double. double Math.floor(d) Returns the closest integer-valued double which is equal to or less than d. double Math.ceil(d) Returns the closest integer-valued double which is equal to or greater than d. double Math.rint(d) Returns the closest integer-valued double to d. long Math.round(d) Returns the long which is closest in value to the double d. int Math.round(f) Returns the int which is closest in value to the float f. Random Numbers double Math.random() Returns a number x in the range, 0.0 <= x < 1.0.

## Other math libraries

Copyleft 2005 Fred Swartz