Summary of Java Math class

Java Math class

As a reminder, the Math class often appears when reading code in programming. .. .. ** It is written as an excerpt. It is not exhaustive. ** **

Field (variable)

E The double value closest to the base of the natural logarithm (Napier, Euler) ʻeis2.718281828459045`.

PI The double value closest to pi π is 3.141592653589793.

Method (function)

abs

A method to find the absolute value. Math.abs (-5) is 5.

max

Returns the larger of the two numbers set in the argument. Math.max (2, 7) is 7.

min

The opposite of max, it returns the smaller of the two numbers set in the argument. Math.max (10, 4) is 4.

pow

Find the power. Math.pow (a, b) returns ʻa ^ b. That is, Math.pow (3.0, 4.0)is81.0`.

sqrt

Find the rounded positive square root. In short, it's a root guy. If the argument is ʻa, the number xsuch thatx ^ 2 = ais obtained. Math.sqrt (9.0)is3.0. It's 3 ^ 2 = 9`!

cbrt

It seeks a cube root. If the argument is ʻa, the number xsuch thatx ^ 3 = ais obtained. Math.cbrt (8.0)is2.0. It's 2 ^ 3 = 8`!

ceil

Round up the argument. Strictly speaking, it returns "the number greater than or equal to the argument and equal to the calculated integer, closest to negative infinity". Math.ceil (1.34) is 2.0. Math.ceil (-3.89) is -3.0.

floor

Truncate the argument. Strictly speaking, it returns "the number less than or equal to the argument and equal to the calculated integer, closest to positive infinity". Math.floor (1.34) is 1.0. Math.floor (-3.89) is -4.0.

round

Returns the number rounded off. In fact, it does some bitwise operations internally, but it's ** rounded **! Math.round (1.34) is 1. Math.round (-3.89) is -4.

rint

Returns the number rounded off. The only difference from round is the argument and return types.

toRadians

Converts arguments expressed in degrees (units: °, degrees) to arcs (units: radians).

• Generally, the conversion between radians and radians is not accurate. By the way, you can also convert with the following formula.

Radian=Every time* π / 180

toDegrees

The opposite of toRadians, it converts the arguments represented by the arc degree method to the frequency method.

• This is not as accurate as to Radians. By the way, you can also convert with the following formula.

Every time=Radian* 180 / π

sin

Returns the sine (sine) of the specified angle. The argument must be expressed in radians. That is, sin30 ° is represented byMath.sin (Math.toRadians (30.0)). However, at least in my environment, when I run Math.sin (Math.toRadians (30.0)), I get 0.49999999999999994, so I think that proper rounding is necessary.

cos

Returns the cosine of the specified angle. The argument must be expressed in radians. That is, cos60 ° is represented byMath.cos (Math.toRadians (60.0)). This also returned 0.5000000000000001. Let's roll it up.

tan

Returns the tangent of the specified angle. The argument must be expressed in radians. That is, tan 45 ° is represented byMath.tan (Math.toRadians (45.0)). This also returned 0.99999999999999999.

asin

Returns the inverse sine (arc sine) of the specified value. The range of angles returned is -π / 2 ≤ x ≤ π / 2. For example, if the argument is ʻa, the size of the angle expressed by the radian method xis obtained so thatsinx = a. Math.asin (0.5)is0.5235987755982989 (≒ π / 6`).

acos

Returns the inverse cosine (arc cosine) of the specified value. The range of angles returned is 0.0 ≤ x ≤ π. For example, if the argument is ʻa, the size of the angle expressed by the radian methodxis obtained so thatcosx = a. Math.acos (0.5)is1.0471975511965979 (≒ π / 3`).

atan

Returns the arctangent of the specified value. The range of angles returned is -π / 2 ≤ x ≤ π / 2. For example, if the argument is ʻa, the size of the angle expressed by the radian method xis obtained so thattanx = a. Math.atan (1.0)is0.7853981633974483 (≒ π / 4`).

atan2

Returns the angle when converted from Cartesian coordinates to polar coordinates. The first argument is the y coordinate and the second argument is the x coordinate. (** Note the order **) In other words, "the angle between the" line segment connecting the origin and the point (x, y) "and the" positive part of the x-axis "in Cartesian coordinates" is returned by the radian method. Math.atan2 (Math.sqrt (3.0), 1.0) is 1.0471975511965976 (≒ π / 3).

random

Returns a random positive value greater than or equal to 0.0 and less than 1.0. Exactly the same as java.util.Random ().

addExtract

Returns the sum of the arguments. Throws an exception if the result overflows an int or long. Math.addExact (1, 5) is 6.

subtractExtract

Returns the difference between the arguments. Throws an exception if the result overflows an int or long. Math.subtractExact (1, 5) is -4.

multiplyExact

Returns the product of the arguments. Throws an exception if the result overflows an int or long. Math.multiplyExact (2, 5) is 10.

incrementExact

Returns the argument incremented by 1. Throws an exception if the result overflows an int or long. If the argument is ʻa, the process is almost the same as ʻa ++.

decrementExact

Returns the argument decremented by 1. Throws an exception if the result overflows an int or long. If the argument is ʻa, the process is almost the same as ʻa--.

negateExact

Returns the negation of the argument. Throws an exception if the result overflows an int or long. If the argument is ʻa, it is almost the same as the process that -a is returned, but if you put ʻInteger.MIN_VALUE in the argument, an exception will occur. (Because int type is -2147483648 ~ 2147483647)

toIntExact

Returns a long argument as an int. Throws an exception if the value does not fit in an int.

floorDiv

Returns the maximum (closest to positive infinity) value less than or equal to the quotient algebra. Math.floorDiv (a, b) returns " floor of the quotient of ʻa divided by b". For example,-5 ÷ 3 is -1.6666 ... , so Math.floorDiv (-5, 3) is -2`.

floorMod

Returns the floor modulus of the argument. Math.floorMod (a, b) returns "too much when ʻa is divided by band its quotient isfloorDiv (a, b)". For example, Math.floorDiv (-5, 3)is-2, so Math.floorMod (-5, 3) is 1`. In other words, the following formula holds.

b = Math.floorDiv(a, b) * b + Math.floorMod(a, b)

exp

Returns the number of Napiers (Euler numbers) ʻe raised to the power of a double value. If the argument is ʻa, ʻe ^ a` is returned.

signum

If the argument is a, When ʻa <0, -1.0, When ʻa = 0, 0.0, Returns 1.0 when ʻa> 0`.

hypot

Returns sqrt (x ^ 2 + y ^ 2). No overflow or underflow will occur along the way. That is, Math.hypot (x, y) returns the "distance from the origin to the point (x, y) on the coordinate plane".

log

Returns the natural logarithmic value of the argument (base e). That is, if the argument is ʻa, it returns the value x such that ʻe ^ x = a.

log10

Returns the common logarithmic value of the argument. That is, if the argument is ʻa, it returns the value xsuch that10 ^ x = a. Math.log10 (1000.0)is3.0`.

Summary

** IMIWAKARAN **