|
| 1 | +""" |
| 2 | +https://en.wikipedia.org/wiki/Taylor_series#Trigonometric_functions |
| 3 | +""" |
| 4 | +from math import factorial, pi |
| 5 | + |
| 6 | + |
| 7 | +def maclaurin_sin(theta: float, accuracy: int = 30) -> float: |
| 8 | + """ |
| 9 | + Finds the maclaurin approximation of sin |
| 10 | +
|
| 11 | + :param theta: the angle to which sin is found |
| 12 | + :param accuracy: the degree of accuracy wanted minimum |
| 13 | + :return: the value of sine in radians |
| 14 | +
|
| 15 | +
|
| 16 | + >>> from math import isclose, sin |
| 17 | + >>> all(isclose(maclaurin_sin(x, 50), sin(x)) for x in range(-25, 25)) |
| 18 | + True |
| 19 | + >>> maclaurin_sin(10) |
| 20 | + -0.544021110889369 |
| 21 | + >>> maclaurin_sin(-10) |
| 22 | + 0.5440211108893703 |
| 23 | + >>> maclaurin_sin(10, 15) |
| 24 | + -0.5440211108893689 |
| 25 | + >>> maclaurin_sin(-10, 15) |
| 26 | + 0.5440211108893703 |
| 27 | + >>> maclaurin_sin("10") |
| 28 | + Traceback (most recent call last): |
| 29 | + ... |
| 30 | + ValueError: maclaurin_sin() requires either an int or float for theta |
| 31 | + >>> maclaurin_sin(10, -30) |
| 32 | + Traceback (most recent call last): |
| 33 | + ... |
| 34 | + ValueError: maclaurin_sin() requires a positive int for accuracy |
| 35 | + >>> maclaurin_sin(10, 30.5) |
| 36 | + Traceback (most recent call last): |
| 37 | + ... |
| 38 | + ValueError: maclaurin_sin() requires a positive int for accuracy |
| 39 | + >>> maclaurin_sin(10, "30") |
| 40 | + Traceback (most recent call last): |
| 41 | + ... |
| 42 | + ValueError: maclaurin_sin() requires a positive int for accuracy |
| 43 | + """ |
| 44 | + |
| 45 | + if not isinstance(theta, (int, float)): |
| 46 | + raise ValueError("maclaurin_sin() requires either an int or float for theta") |
| 47 | + |
| 48 | + if not isinstance(accuracy, int) or accuracy <= 0: |
| 49 | + raise ValueError("maclaurin_sin() requires a positive int for accuracy") |
| 50 | + |
| 51 | + theta = float(theta) |
| 52 | + div = theta // (2 * pi) |
| 53 | + theta -= 2 * div * pi |
| 54 | + return sum( |
| 55 | + (((-1) ** r) * ((theta ** (2 * r + 1)) / factorial(2 * r + 1))) |
| 56 | + for r in range(accuracy) |
| 57 | + ) |
| 58 | + |
| 59 | + |
| 60 | +def maclaurin_cos(theta: float, accuracy: int = 30) -> float: |
| 61 | + """ |
| 62 | + Finds the maclaurin approximation of cos |
| 63 | +
|
| 64 | + :param theta: the angle to which cos is found |
| 65 | + :param accuracy: the degree of accuracy wanted |
| 66 | + :return: the value of cosine in radians |
| 67 | +
|
| 68 | +
|
| 69 | + >>> from math import isclose, cos |
| 70 | + >>> all(isclose(maclaurin_cos(x, 50), cos(x)) for x in range(-25, 25)) |
| 71 | + True |
| 72 | + >>> maclaurin_cos(5) |
| 73 | + 0.28366218546322675 |
| 74 | + >>> maclaurin_cos(-5) |
| 75 | + 0.2836621854632266 |
| 76 | + >>> maclaurin_cos(10, 15) |
| 77 | + -0.8390715290764525 |
| 78 | + >>> maclaurin_cos(-10, 15) |
| 79 | + -0.8390715290764521 |
| 80 | + >>> maclaurin_cos("10") |
| 81 | + Traceback (most recent call last): |
| 82 | + ... |
| 83 | + ValueError: maclaurin_cos() requires either an int or float for theta |
| 84 | + >>> maclaurin_cos(10, -30) |
| 85 | + Traceback (most recent call last): |
| 86 | + ... |
| 87 | + ValueError: maclaurin_cos() requires a positive int for accuracy |
| 88 | + >>> maclaurin_cos(10, 30.5) |
| 89 | + Traceback (most recent call last): |
| 90 | + ... |
| 91 | + ValueError: maclaurin_cos() requires a positive int for accuracy |
| 92 | + >>> maclaurin_cos(10, "30") |
| 93 | + Traceback (most recent call last): |
| 94 | + ... |
| 95 | + ValueError: maclaurin_cos() requires a positive int for accuracy |
| 96 | + """ |
| 97 | + |
| 98 | + if not isinstance(theta, (int, float)): |
| 99 | + raise ValueError("maclaurin_cos() requires either an int or float for theta") |
| 100 | + |
| 101 | + if not isinstance(accuracy, int) or accuracy <= 0: |
| 102 | + raise ValueError("maclaurin_cos() requires a positive int for accuracy") |
| 103 | + |
| 104 | + theta = float(theta) |
| 105 | + div = theta // (2 * pi) |
| 106 | + theta -= 2 * div * pi |
| 107 | + return sum( |
| 108 | + (((-1) ** r) * ((theta ** (2 * r)) / factorial(2 * r))) for r in range(accuracy) |
| 109 | + ) |
| 110 | + |
| 111 | + |
| 112 | +if __name__ == "__main__": |
| 113 | + print(maclaurin_sin(10)) |
| 114 | + print(maclaurin_sin(-10)) |
| 115 | + print(maclaurin_sin(10, 15)) |
| 116 | + print(maclaurin_sin(-10, 15)) |
| 117 | + |
| 118 | + print(maclaurin_cos(5)) |
| 119 | + print(maclaurin_cos(-5)) |
| 120 | + print(maclaurin_cos(10, 15)) |
| 121 | + print(maclaurin_cos(-10, 15)) |
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