POISSON.DIST DAX Function (Statistical)
Returns the Poisson distribution. A common application of the Poisson distribution is predicting the number of events over a specific time, such as the number of cars arriving at a toll plaza in 1 minute.
Syntax
Parameter | Attributes | Description |
---|---|---|
X |
The number of events. |
|
Mean |
The expected numeric value. |
|
Cumulative |
A logical value that determines the form of the probability distribution returned. If cumulative is TRUE, POISSON.DIST returns the cumulative Poisson probability that the number of random events occurring will be between zero and x inclusive; if FALSE, it returns the Poisson probability mass function that the number of events occurring will be exactly x. |
Return values
Returns the Poisson distribution.
Remarks
If x is not an integer, it is rounded.
If x or mean is nonnumeric, POISSON.DIST returns the #VALUE! error value.
If x < 0, POISSON.DIST returns the #NUM! error value. If mean < 0, POISSON.DIST returns the #NUM! error value.
Examples
-- POISSON.DIST returns the Poisson distribution -- Use case: predicting the number of events over -- a specific time, such as the number of customers -- entering a store in 1 hour -- POISSON.DIST ( Value, Mean, Cumulative ) DEFINE VAR Mean = 10 -- Expected number of customers in 1 hour VAR Vals = GENERATESERIES ( 0, 20, 1 ) VAR CumulativeTrue = TRUE -- Cumulative distribution function VAR CumulativeFalse = FALSE -- Probability density function EVALUATE ADDCOLUMNS ( Vals, "Poisson Distr.", -- Probability density function FORMAT ( POISSON.DIST ( [Value], Mean, CumulativeFalse ), "#,0.00000" ), "Poisson Distr. Cumulative", -- Cumulative distribution function FORMAT ( POISSON.DIST ( [Value], Mean, CumulativeTrue ), "#,0.00000" ) )
Value | Poisson Distr. | Poisson Distr. Cumulative |
---|---|---|
0 | 0.00005 | 0.00005 |
1 | 0.00045 | 0.00050 |
2 | 0.00227 | 0.00277 |
3 | 0.00757 | 0.01034 |
4 | 0.01892 | 0.02925 |
5 | 0.03783 | 0.06709 |
6 | 0.06306 | 0.13014 |
7 | 0.09008 | 0.22022 |
8 | 0.11260 | 0.33282 |
9 | 0.12511 | 0.45793 |
10 | 0.12511 | 0.58304 |
11 | 0.11374 | 0.69678 |
12 | 0.09478 | 0.79156 |
13 | 0.07291 | 0.86446 |
14 | 0.05208 | 0.91654 |
15 | 0.03472 | 0.95126 |
16 | 0.02170 | 0.97296 |
17 | 0.01276 | 0.98572 |
18 | 0.00709 | 0.99281 |
19 | 0.00373 | 0.99655 |
20 | 0.00187 | 0.99841 |
Last update: Nov 7, 2024 » Contribute » Show contributors
Contributors: Alberto Ferrari, Marco Russo
Microsoft documentation: https://docs.microsoft.com/en-us/dax/poisson-dist-function-dax