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Python编码下面的三角函数包括以下种类：
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acos(x) //返回x的反余弦弧度值。 asin(x) //返回x的反正弦弧度值。 atan(x) //返回x的反正切弧度值。 atan2(y, x) //返回给定的 X 及 Y 坐标值的反正切值。 cos(x) //返回x的弧度的余弦值。 hypot(x, y) //返回欧几里德范数 sqrt(x*x + y*y)。 sin(x) //返回的x弧度的正弦值。 tan(x) //返回x弧度的正切值。 degrees(x) //将弧度转换为角度,如degrees(math.pi/2) ， 返回90.0 radians(x) //将角度转换为弧度
下面介绍了Python计算三角函数之asin()方法的使用（其它只需替换上述方法即可），返回x的反正弦，以弧度表示，代码如下：
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#!/usr/bin/python import math print "asin(0.64) : ", math.asin(0.64) print "asin(0) : ", math.asin(0) print "asin(-1) : ", math.asin(-1) print "asin(1) : ", math.asin(1) #运行结果如下：asin(0.64) : 0.694498265627asin(0) : 0.0asin(-1) : -1.57079632679asin(1) : 1.57079632679
I wrote this in Tkinter for you, in case you don't know Tkinter, it is a built-in module for most python versions.
If you want a commandline version, you can ask me, but tell you what, since those values are all
float numbers, so it's hard to get a precise graph in commandline window.
Well, in this version, I enlarged each element's position by 40 and then change them to integer, guess this is an endurable loss of precision.
#
from math import radians
from math import sin
from Tkinter import *
pos = []
xPos = 0
centerX = 0
centerY = 0
for deg in range(-360, 361, 10):
pos.append([xPos, int(40*(sin(radians(deg))))]) #1000 too big for my screen
xPos+=1
if deg == 0:
centerX = xPos-1
centerY = pos[-1][1]
root = Tk()
root.title('trianble graph from -180 to 180')
width, height = 550, 450
mHei = height/2
mWid = width/2
canvas = Canvas(root, width=width, height=height)
canvas.create_line(0, mHei, width, mHei) #x axis
canvas.create_line(mWid, 0, mWid, height) #y axis
xStep = (width-150)/len(pos)
yStep = (height-150)/len(pos)
radius = 3
# the middle point (sin(0) is first drawn and used as position reference for all
canvas.create_oval(mWid-radius, mHei-radius, mWid+radius, mHei+radius, fill='green')
print pos
print xStep, yStep, centerX, centerY
#exit(0)
for i in pos:
if i[0] == centerX: #center processed already.
continue
x = mWid + xStep*(i[0]-centerX)
# y is smaller, the bigger the value, so use minus
y = mHei - yStep*(i[1]-centerY)
canvas.create_oval(x-radius, y-radius, x+radius, y+radius, fill='green')
canvas.pack()
root.mainloop()
在python中，有一个math module，你可以import math，里面有math.sin(), math.cos(), math.asin()和math.acos()四个函数。相信你也知道asin和acos的意思，就是arcsin和arccos。有了这四个函数你就可以求函数值和角度了。但是要注意括号里面填的数值，要用弧度制。
I just wrote an simple one for one other guy.
You may check it here and see if it's useful for you.
在python中,有一个math
module,你可以import
math,
里面有math.sin(),math.cos(),math.asin()和math.acos()四个函数.
有了这四个函数你就可以求函数值和角度了.
注意:括号里面填的数值,要用弧度制.
Python的三角函数sin()，输入参数必须是弧度，所以要把角度变换为弧度
import math
# .... 输入度数到 degrees 变量....
# 例子里用 30度计算
degrees=30
radians = degrees * math.pi / 180.0
value = round( math.sin(radians), 4)
print(value)
