Python Mathematical Functions (โมดูล math)

โมดูล math ให้ Mathematical Functions สำหรับ Integer/Float (ไม่รองรับ Complex -> ใช้ cmath)

import math

Constants

Constant	ค่า	คำอธิบาย
`math.pi`	3.141592653589793	π
`math.e`	2.718281828459045	Natural Base
`math.tau`	6.283185307179586	2π (Python 3.6+)
`math.inf`	inf	Positive Infinity
`math.nan`	nan	Not a Number

Number Theory & Representation

Function	คำอธิบาย
`ceil(x)`	ปัดขึ้น (Smallest Integer ≥ x)
`floor(x)`	ปัดลง (Largest Integer ≤ x)
`trunc(x)`	ตัดทศนิยม (Toward Zero)
`fabs(x)`	Absolute Value (Float)
`factorial(x)`	Factorial (x ≥ 0 Integer)
`gcd(a, b)`	Greatest Common Divisor
`lcm(a, b)`	Least Common Multiple (3.9+)
`fsum(iterable)`	Sum แบบแม่นยำ (Precision)
`prod(iterable)`	Product (3.8+)
`isqrt(n)`	Integer Square Root (3.8+)
`copysign(x, y)`	x ด้วย Sign ของ y
`remainder(x, y)`	IEEE 754 Remainder

Special Value Checks

`isfinite(x)`	ไม่ใช่ Inf/NaN
`isinf(x)`	เป็น Infinity
`isnan(x)`	เป็น NaN
`isclose(a, b, rel_tol=1e-9, abs_tol=0)`	เปรียบเทียบ Float ใกล้เคียง

Power & Logarithmic

Function	คำอธิบาย
`pow(x, y)`	x^y (Float)
`sqrt(x)`	√x
`exp(x)`	e^x
`expm1(x)`	e^x - 1 (แม่นยำสำหรับ x ใกล้ 0)
`log(x[, base])`	Log Base e (Default) หรือ Base ที่กำหนด
`log2(x)`	Log Base 2
`log10(x)`	Log Base 10
`log1p(x)`	ln(1+x) (แม่นยำสำหรับ x ใกล้ 0)

Trigonometric & Angular

Function	คำอธิบาย
`sin(x)`, `cos(x)`, `tan(x)`	Input เป็น Radian
`asin(x)`, `acos(x)`, `atan(x)`	Inverse (Output Radian)
`atan2(y, x)`	Angle จาก (x,y) Quadrant ถูกต้อง
`hypot(x, y)`	√(x²+y²) - ระยะทาง Euclidean
`degrees(rad)`	Radian -> Degree
`radians(deg)`	Degree -> Radian

Hyperbolic

`sinh/cosh/tanh`	Hyperbolic Functions
`asinh/acosh/atanh`	Inverse Hyperbolic

โค้ดตัวอย่าง

import math

# Basic
print(f"π = {math.pi}, e = {math.e}, τ = {math.tau}")
print(f"ceil(23.56) = {math.ceil(23.56)}, floor(23.56) = {math.floor(23.56)}")
print(f"copysign(10, -15) = {math.copysign(10, -15)}")
print(f"fabs(-96) = {math.fabs(-96)}")
print(f"factorial(5) = {math.factorial(5)}")
print(f"gcd(24, 56) = {math.gcd(24, 56)}")
print(f"fsum([12, 4.25, 89, 3.02, -65.23]) = {math.fsum([12, 4.25, 89, 3.02, -65.23])}")

# Power/Log
print(f"5^8 = {math.pow(5, 8)}")
print(f"√400 = {math.sqrt(400)}")
print(f"e^5 = {math.exp(5)}")
print(f"log(625, 5) = {math.log(625, 5)}")
print(f"log2(1024) = {math.log2(1024)}")
print(f"log10(1024) = {math.log10(1024)}")

# Trigonometric
print(f"sin(60°) = {math.sin(math.radians(60))}")
print(f"cos(π) = {math.cos(math.pi)}")
print(f"atan2(1, 1) = {math.atan2(1, 1)} rad = {math.degrees(math.atan2(1, 1))}°")
print(f"hypot(3, 4) = {math.hypot(3, 4)}")

# Special Values
print(f"isnan(nan) = {math.isnan(float('nan'))}")
print(f"isinf(inf) = {math.isinf(float('inf'))}")
print(f"isfinite(45) = {math.isfinite(45)}")
print(f"isclose(0.1+0.2, 0.3) = {math.isclose(0.1+0.2, 0.3)}")

New in Python 3.11+

math.exp2(x) - 2^x
math.log2p(x) - log2(1+x)
math.cbrt(x) - Cube Root
math.sumprod(iter1, iter2) - Sum of Products