python math模塊

1.math簡介?

>>>?import?math

>>>dir(math)???????????#這句可查看所有函數名列表

['__doc__',?'__name__',?'__package__',?'acos',?'acosh',?'asin',?'asinh',?'atan',?'atan2',?'atanh',?'ceil',?'copysign',?'cos',?'cosh',?'degrees',?'e',?'erf',?'erfc',?'exp',?'expm1',?'fabs',?'factorial',?'floor',?'fmod',?'frexp',?'fsum',?'gamma',?'hypot',?'isinf',?'isnan',?'ldexp',?'lgamma',?'log',?'log10',?'log1p',?'modf',?'pi',?'pow',?'radians',?'sin',?'sinh',?'sqrt',?'tan',?'tanh',?'trunc']

>>>help(math)?????????#查看具體定義及函數0原型

>>>help(math.function)?#查看math模塊下函數的功能

2.常用函數

ceil(x)?取頂

????Return?the?ceiling?of?x?as?a?float.

????This?is?the?smallest?integral?value?>=?x.

floor(x)?取底

Return?the?floor?of?x?as?a?float.

This?is?the?largest?integral?value?<=?x.

fabs(x)?取絕對值

Return?the?absolute?value?of?the?float?x.

factorial?(x)?階乘

Find?x!.?Raise?a?ValueError?if?x?is?negative?or?non-integral.

hypot(x,y)??求直角三角形的斜邊長

Return?the?Euclidean?distance,?sqrt(x*x?+?y*y)

pow(x,y)?x的y次方

Return?x**y?(x?to?the?power?of?y).

sqrt(x)?開平方

Return?the?square?root?of?x.

log(x[,base])

Return?the?logarithm?of?x?to?the?given?base.

?If?the?base?not?specified,?returns?the?natural?logarithm?(base?e)?of?x.

log10(x)

Return?the?base?10?logarithm?of?x.

trunc(x)??截斷取整數部分

Truncates?x?to?the?nearest?Integral?toward?0.?Uses?the?__trunc__?magic?method.

isnan?(x)??判斷是否NaN(not?a?number)

Check?if?float?x?is?not?a?number?(NaN)

degrees(x)?弧度轉角度

Convert?angle?x?from?radians?to?degrees.

radians(x)?角度轉弧度

Convert?angle?x?from?degrees?to?radians.?

另外該模塊定義了兩個常量:?

e?=?2.718281828459045

pi?=?3.141592653589793