What does ln mean in python?

Umme Ammara

Python’s numpy.log[] is a mathematical function that computes the natural logarithm of an input array’s elements.

The natural logarithm is the inverse of the exponential function, such that log [exp[x]] = x.

Syntax

numpy.log is declared as shown below:

numpy.log[x, /, out=None, *, where=True, casting='same_kind', order='K', dtype=None, subok=True[, signature, extobj]] =

In the syntax above, x is the non-optional parameter and the rest are optional parameters.

A universal function [ufunc] is a function that operates on ndarrays in an element-by-element fashion. The log[] method is a universal function.

Parameters

The numpy.log[] method takes the following compulsory parameter:

x [array-like] - input array.

The numpy.log[] method takes the following optional parameters:

Return value

numpy.log[] returns the element-wise natural logarithm of values in x. If x is scalar, the return type is also scalar.

If x is a real-valued data type, the return type will also be a real value. If a value cannot be written as a real value, then NaN is returned.
If x is a complex-valued input, the numpy.log method has a branch cut [-inf,0], and it is continuous above it.

Examples

In the example below, numpy.log[] computes the natural logarithm of two numbers, a and b:

import numpy as np
a = 0.5 
b = np.exp[8.9]
print [np.log[a]]
print [np.log[b]]

In the example below, numpy.log[] computes the element-wise natural logarithm of the array arr1:

import numpy as np
arr1 = np.array[[1,2,0,3,4]]
print [np.log[arr1]]

CONTRIBUTOR

Umme Ammara

Python can be used just like a pocket calculator. In addition to addition, subtraction, multiplication and division, you can calculate exponents and logarithms with Python. Exponent and logarithm functions are imported from the math module which is part of the Python Standard Library. This means all the functions in the math module are available in any Python installation.

In this short post, you'll learn how to calculate exponents and logarithms in Python.

Exponent and Logarithm Functions¶

The following exponent and logarithm functions can be imported from Python's math module:

log
log10
exp
e
pow[x,y]
sqrt

Note that Python's

log

function calculates the natural log of a number. Python's

log10

function calculates the base-10 log of a number. Python doesn't have an

function, use

log

for natural logarithms.

Let's try a couple of examples. In the examples below, the >>> prompt is not meant to be typed. >>> is used to denote the Python REPL or Python prompt. Alternatively, you can enter these examples into a Jupyter notebook code cell. Note how the first line of code imports logarithm and power functions from Python's math module.

>>> from math import log, log10, exp, e, pow, sqrt
>>> log[3.0*e**3.4]         # note: natural log
4.4986122886681095

Now let's try a problem: A right triangle has side lengths 3 and 4. What is the length of the hypotenuse?

>>> sqrt[3**2 + 4**2]
5.0

The power function pow[] works like the ** operator. pow[] raises a number to a power.

Summary¶

The following exponent and logarithm functions are part of Python's math module:

Math functionNameDescriptionExampleResult

`math.e`	Euler's number	mathematical constant $e$	`math.e`	`2.718`
`math.exp[]`	exponent	$e$ raised to a power	`math.exp[2.2]`	`9.025`
`math.log[]`	natural logarithm	log base $e$	`math.log[3.1]`	`400`
`math.log10[]`	base 10 logarithm	log base 10	`math.log10[100]`	`2.0`
`math.pow[]`	power	raises a number to a power	`math.pow[2,3]`	`8.0`
`math.sqrt[]`	square root	square root of a number	`math.sqrt[16]`	`4.0`

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What is ln in Python?

Python | Decimal ln[] method Decimal#ln[] : ln[] is a Decimal class method which returns the natural [base e] logarithm of the Decimal value. Syntax: Decimal.ln[] Parameter: Decimal values. Return: the natural [base e] logarithm of the Decimal value.

What does ln [] stand for?

Ln: Ln is called the natural logarithm. It is also called the logarithm of the base e. Here, e is a number which is an irrational and transcendental number and is approximately equal to 2.718281828459… The natural logarithm [ln] is represented as ln x or loge x.

Does Python have ln?

Python's log10 function calculates the base-10 log of a number. Python doesn't have an ln function, use log for natural logarithms.

What is ln of a value?

A logarithm [LN] is a concept in mathematics that denotes the number of times a number has to be multiplied by itself in order to arrive at a specified value. In mathematical terms, a logarithm of a number is the exponent that is used to raise another number, the base, in order to arrive at that number.