In probability theory and statistics, the cumulative distribution function (CDF) of a real-valued random variable , or just distribution function of , evaluated at , is the probability that will take a value less than or equal to .

累积分布函数 （英語： cumulative distribution function，CDF）或 概率分布函数，简称 分布函数，是 概率密度函數 的积分，能完整描述一個實 随机变量 的 概率分佈。 在標量 連續分佈 的情況下，它給出了從負無窮到 的 概率密度函數 下的面積。 累積分佈函數 也用於指定 多元隨機變量 （英语：Multivariate random variable） 的分佈。 對於所有 實數 值的 随机变量 ，累积分布函数定義如下 [1]:p. 77： 其中右侧表示随机变量 取值小于或等于 的 概率。 對於 位于半闭区间 的概率， …

The cumulative distribution function (CDF) calculates the cumulative probability for a given x-value. Use the CDF to determine the likelihood that a random observation taken from the population will be less than or equal to a particular value.

2024年9月3日 · The Cumulative Distribution Function (CDF) of a random variable is a mathematical function that provides the probability that the variable will take a value less than or equal to a particular number. The CDF starts at 0 for the smallest possible value of X and increases to 1 as x approaches the largest possible value of X.

cdf is a generic function that accepts either a distribution by its name name or a probability distribution object pd. It is faster to use a distribution-specific function, such as normcdf for the normal distribution and binocdf for the binomial distribution.

1 f(t) dt is called the cumulative distribution function (CDF). De nition: The probability density function f(x) = 1 1 is called the 1+x2 Cauchy distribution. Find the cumulative distribution function of the Cauchy distribution. We do not know yet how to compute this but learn a technique later.

Definition: For a discrete random variable X X with probability mass function f f, we define the cumulative distribution function (c.d.f.) of X X, often denoted by F F, to be: F(x) = P(X ≤ x), − ∞ <x <∞ F (x) = P (X ≤ x), − ∞ <x <∞. As a quick comparison, allow us to discuss the difference between a pmf and a cdf.

2025年3月5日 · The distribution function D (x), also called the cumulative distribution function (CDF) or cumulative frequency function, describes the probability that a variate X takes on a value less than or equal to a number x.

2024年3月16日 · A cumulative distribution function (CDF) describes the probabilities of a random variable having values less than or equal to x. It is a cumulative function because it sums the …

2011年7月19日 · The CDF is a measure of how much a variable accumulates. It may help to look at this plot example. The CDF's are the black and blue lines, whereas the survival function (1-CDF) is the orange line. The likelihood of finding 200 …