Exponential Distribution

An exponential distribution is a continuous probability distribution that is not symmetric around its mean. It is actually a skewed distribution, characterized by its right-skewed or positively skewed bell-shaped curve. The mean is located towards the right side of the curve, and the data is distributed more densely towards the left side.

It is used in all sorts of industries such as Probability Theory, Financial Analysis, Quality Control, Psychology and Social Sciences, Industrial Engineering as well as Machine Learning and Data Science.

Exponential cumulative distribution
Exponential probability density function

Exponential Probability Distribution in MatDeck

In MatDeck, the exponentialdist function is used calculate the cumulative distributions function for the exponential distribution. The function only requires 3 arguments and can handle several different data types. We can see the function looks like when we plot an Exponential Distribution, to do this we call the exponetialdist function inside the curve2d function.

Exponential probability distribution

The first argument is the value or values for which you would like to calculate the exponential CDF, it can be a single number or it can be a vector which contains multiple different value which the exponential function would be applied to. The second argument is the mean/ average of the population, this can be directly obtained from data using the average function. The final argument is the standard deviation of the data, just like the mean/average you can directly calculate the standard deviation.

Here is an in-depth look at all the Exponential Probability Distribution functions:

Inverse Exponential Distribution

The inverse exponential distribution is the mathematical operation that calculates the value corresponding to a specified probability under a given exponential distribution. It provides the inverse mapping of the cumulative distribution function (CDF) of the exponential distribution.

A MatDeck Document which features the Exponential Distribution and its plot
A MatDeck Document which features the Exponential Distribution and its plot

Exponential Distributions in Python

The MD Python library enables Python users to access and utilize MatDeck’s comprehensive mathematical and statistical functions seamlessly. By incorporating MatDeck’s straightforward syntax and user-friendly functions, it seamlessly integrates with Python, offering a significant speed boost. Furthermore, since MatDeck’s statistical functions are implemented in C++, Python users can achieve high-speed performance comparable to C++ while retaining Python’s renowned simplicity.

Where is the Exponential Distribution used?

The Exponential Distribution is used in various fields when dealing with continuous variables that represent the time between events in a Poisson process. It is preferred over other distributions in certain scenarios because:

  • It is suitable for modelling continuous data representing the time between events.
  • It is applicable when events occur independently and follow an exponential decay pattern.
  • It assumes memorylessness, making it suitable for independent events.
  • It has a simple parameterization with the rate parameter, making it easy to work with mathematically.
  • It is analytically tractable for calculating probabilities and statistics.
  • It is often used for modelling the lifetime of products, waiting times, and reliability analysis.

However, the Exponential Distribution may not be appropriate if events do not occur independently or if the data exhibits a different pattern of decay. In such cases, alternative distributions may be more suitable based on the specific data characteristics and research question.