Continuous uniform / rectangular distribution

Continuous uniform / rectangular distribution

Understanding Continuous Uniform Distribution

  • Continuous Uniform Distribution, also known as Rectangular Distribution, represents a situation where each value within a certain range is equally likely to be observed.
  • Distinct to this type of distribution is how the probability density function remains constant within the specified range, a characteristic depicted by a rectangle in a graph. Hence the term “rectangular distribution”.
  • Key parameters of a continuous uniform distribution are the minimum (a) and maximum (b) values that define the range. Together, they specify the area of probability.

Properties of Continuous Uniform Distribution

  • The PDF (Probability Density Function) of a continuous uniform distribution is 1/(b - a) for a ≤ x ≤ b. For values outside this range, the probability is zero.
  • The CDF (Cumulative Distribution Function) calculates the probability that a random variable X will take a value less than or equal to a given value x. It’s defined as (x - a)/(b - a) for a ≤ x ≤ b.
  • The mean (μ) of a continuous uniform distribution is given by (a + b) / 2, which is the midpoint of the distribution range.
  • The variance (σ^2) is given by (b - a)² / 12. It provides the measurement of the spread around the mean.

Sampling from a Continuous Uniform Distribution

  • When drawing a sample from a continuous uniform distribution, every value within the defined range has an exactly equal probability of being chosen.
  • This uniform probability is denoted by a horizontal line in the probability density function.
  • This ability to produce an equal chance of selection makes this distribution useful in several practical applications, such as random number generation.

Application and Interpretation of Continuous Uniform Distribution

  • Continuous uniform distribution allows modellers to assign equal probabilities to all the points of a certain range.
  • In forecasting and decision-making processes, a continuous uniform distribution might be used when there is maximum uncertainty about the likelihood of an outcome.
  • The simplicity of continuous uniform distribution is a key advantage. However, real-world problems are often more complex and may require different types of distribution.

Limitations of the Continuous Uniform Distribution

  • The main limitation of a continuous uniform distribution is that it assumes an unrealistically constant probability for all values within a given range.
  • It doesn’t allow for the fact that in many real-world scenarios, certain outcomes within a range may be more likely than others.
  • It assumes perfect information about the minimum and maximum values, which might not always be possible.