Thursday, October 5, 2017

Adventures in Python: Trigonometric Tables

Adventures in Python: Trigonometric Tables

One of the many mathematical modules available for Python is the math module.  The math functions work with real numbers. 

The program highlighted today also features the for loop.  The for loop is structured differently from what I’m used to.  The for loop works with a range or a list instead of a count of values. 

The range function creates a list of integers, which varies with the syntax:

range(n):  creates a list of integers from 0 to n-1 (the n-1 will take getting used to)
range(a,b):  creates a list of integers from a to b-1

The default angle measurement in Python is radians.  The program builds a tables in increments of 10°, so I must use the math.radians function to convert angles to radians for the table to work properly.

# Program 003:  Trig tables
# Python works with radians
# If you want degrees, use the math.radians, math.degrees to convert

# Import the math library
import math

# Header
print("Angle","sin","cos","tan")

# Build a table with 0 to 180 degrees of trig (sin, cos, tan)
# range:  range(start, stop, step)
# range ends when stop is equalled or exceeded
# since I want 180, I will tip the upper limit to 181
# The for structure defaults to integers
# For structure is used

# rounded values
print("Rounded to 6 decimal places")
print("A list format is used")
print(["angle"," sin "," cos "," tan "])
for k in range(0,181,10):
    # round each compoment
    s = round(math.sin(math.radians(k)),6)
    c = round(math.cos(math.radians(k)),6)
    t = round(math.tan(math.radians(k)),6)
    print([k,s,c,t])

Output:

Angle sin cos tan
Rounded to 6 decimal places
A list format is used
['angle', ' sin ', ' cos ', ' tan ']
[0, 0.0, 1.0, 0.0]
[10, 0.173648, 0.984808, 0.176327]
[20, 0.34202, 0.939693, 0.36397]
[30, 0.5, 0.866025, 0.57735]
[40, 0.642788, 0.766044, 0.8391]
[50, 0.766044, 0.642788, 1.191754]
[60, 0.866025, 0.5, 1.732051]
[70, 0.939693, 0.34202, 2.747477]
[80, 0.984808, 0.173648, 5.671282]
[90, 1.0, 0.0, 1.633123935319537e+16]
[100, 0.984808, -0.173648, -5.671282]
[110, 0.939693, -0.34202, -2.747477]
[120, 0.866025, -0.5, -1.732051]
[130, 0.766044, -0.642788, -1.191754]
[140, 0.642788, -0.766044, -0.8391]
[150, 0.5, -0.866025, -0.57735]
[160, 0.34202, -0.939693, -0.36397]
[170, 0.173648, -0.984808, -0.176327]
[180, 0.0, -1.0, -0.0]

Eddie


This blog is property of Edward Shore, 2017.

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