CODEWITHSUNDEEP
pythoncalculatortrigonometry
tafelrunde
tafelrunde

Reputation: 128

Calculation of trigonometric functions in python

How does Python calculate trigonometric functions? I try to calculate using

x = ((0.1-0.001)/2)*math.sin(((1/20)*math.pi*20)+(0.5*math.pi*1))+((0.1-0.001)/2)+0.001

I'm getting

x = 0.1

why is that? in a usual calculator (radian) i'm getting 0.001

Upvotes: 1

Views: 1706

Answers (3)

Vidhya G
Vidhya G

Reputation: 2320

Just make your integers such as 2 float 2.0, else Python 2.x uses integer division, also known as floor division (rounding towards minus infinity e.g. -9/8 gives -2, 9/8 gives 1), when dividing integers by other integers (whether plain or long):

x = ((0.1-0.001)/2.0)*math.sin(((1/20.0)*math.pi*20)+(0.5*math.pi*1))+((0.1-0.001)/2.0)+0.001

and:

print x
0.001

Upvotes: 1

A.J. Uppal
A.J. Uppal

Reputation: 19264

In , python takes the floor of integer division. Thus, you need to import division from the __future__ library at the top of your program.

from __future__ import division
x = ((0.1-0.001)/2)*math.sin(((1/20)*math.pi*20)+(0.5*math.pi*1))+((0.1-0.001)/2)+0.001
print x

Upvotes: 3

Kasravnd
Kasravnd

Reputation: 107287

In Python 2, / is integer division,you need to import __future__ .division for floating division :

>>> from __future__ import division
>>> import math
>>> x = ((0.1-0.001)/2)*math.sin(((1/20)*math.pi*20)+(0.5*math.pi*1))+((0.1-0.001)/2)+0.001
>>> x
0.001

Upvotes: 4

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