HomeSearch | ## Python Math ExamplesUse math methods. Review methods like sqrt, math.floor and math.ceil. | |

## Math.In ancient times, great advances were made in mathematics. A scroll shows a circle. It calculates its area. Today computers do these calculations. | ||

## In Python we discovermany prebuilt functions. Consider a square root. We just call math.sqrt. No scroll is required for this calculation. | ||

## Floor, ceil.Two common math functions are floor and ceil. Floor removes the digits past the decimal place. In this example it changes 100.7 to 100.floor
| Python program that imports math
import math
# Fractional number.
n = 100.7
# Absolute value.
print(math.floor(n))
print(math.ceil(n))
Output
100
101 | |

## Abs built-in.This is a built-in function in Python. We invoke it with one argument. Abs returns the absolute value of that argument.abs | ||

## Round.This method rounds a number up or down. We call it with a float argument. We can specify how many digits past the decimal place we want to keep.round | ||

## Sum, fsum.With sum, we add together the elements in a list. Fsum is a more accurate way to sum floating-point numbers. On integers, the methods are equal. But fsum is better for floats.sum
| Python program that uses sum, fsum
import math
# Input list.
values = [0.9999999, 1, 2, 3]
# Sum values in list.
r = sum(values)
print(r)
# Sum values with fsum.
r = math.fsum(values)
print(r)
Output
6.999999900000001
6.9999999 | |

## Truncate.Truncating a number removes everything past the decimal place. This does not round the number. Instead it just eliminates the fractional part.
| Python program that uses math.trunc
import math
# Truncate this value.
value1 = 123.45
truncate1 = math.trunc(value1)
print(truncate1)
# Truncate another value.
value2 = 345.67
truncate2 = math.trunc(value2)
print(truncate2)
Output
123
345 | |

## Pow built-in.Exponentiation multiplies a number by itself a certain number of times. With math.pow we apply this operation. Math.pow is similar to the ** operator.
| Python program that uses math.pow
import math
# Use math.pow method.
a = math.pow(2, 3)
# Use operator.
b = 2 ** 3
# Print results.
print(a)
print(b)
Output
8.0
8 | |

## Sqrt.In most programs, we do not need square roots. But when we do, the math.sqrt method is useful. It receives one argument. It returns the square root (in floating-point form).
| Python program that uses math.sqrt
import math
value1 = 9
value2 = 16
value3 = 100
# Use sqrt method.
print(math.sqrt(value1))
print(math.sqrt(value2))
print(math.sqrt(value3))
Output
3.0
4.0
10.0 | |

## Pi, E.You probably know the approximate values of E and pi. And you could specify these directly in a Python program. But with math.e and math.pi, we avoid this hassle. | Python program that uses math.e, pi
import math
# This returns the value of e.
print(math.e)
# And this is pi.
print(math.pi)
Output
2.718281828459045
3.141592653589793 | |

## Compound interest.Math is used in the real world. Please also check out the compound_interest Python implementation. It uses pow to compute an exponential function.Compound Interest | ||

## Math is everywhere.It is possible to directly compute mathematical functions. We could add methods that use arithmetic operators. But this adds complexity. It bloats programs.
| ||

## Instead,we can use built-ins. These are found in the default and math modules. This approach is more effective. It is simpler. It makes programs easier to understand and maintain. | ||

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