GAMMADIST
- GAMMADIST(x, alpha, beta, cumulative)[source]
Calculates the gamma distribution probability density (PDF) or cumulative distribution (CDF).
GAMMADIST evaluates either the probability density function (PDF) or the cumulative distribution function (CDF) of the gamma distribution for the given input(s).
- Parameters:
The input value(s) at which to evaluate the distribution (must be ≥ 0).
Supported types:
INTEGER
DECIMAL
INTEGER_ARRAY
DECIMAL_ARRAY
alpha (
Operand|int|float) –The shape parameter α of the distribution (must be > 0).
Supported types:
INTEGER
DECIMAL
INTEGER_ARRAY
DECIMAL_ARRAY
beta (
Operand|int|float) –The scale parameter β of the distribution (must be > 0).
Supported types:
INTEGER
DECIMAL
INTEGER_ARRAY
DECIMAL_ARRAY
cumulative (
Operand|bool) –Boolean flag to determine calculation type:
False / 0: PDF
True / 1: CDF
Supported types:
BOOLEAN
BOOLEAN_ARRAY
- Return type:
- Returns:
A formula object evaluating to the gamma distribution value(s).
Returns DECIMAL if all inputs are scalar
Returns DECIMAL_ARRAY if any input is an array
Supported types:
DECIMAL
DECIMAL_ARRAY
- Raises:
ValueError – If x, alpha, or beta are not numeric types
ValueError – If cumulative is not boolean-compatible
Examples
Probability density function (PDF):
GAMMADIST(2.0, 3.0, 1.0, False) # Returns the PDF at x=2 for a gamma distribution with shape=3, scale=1
Cumulative distribution function (CDF):
GAMMADIST(2.0, 3.0, 1.0, True) # Returns the CDF at x=2 for a gamma distribution with shape=3, scale=1
Array inputs:
GAMMADIST(my_table["value"], 3.0, 1.0, True) # Returns an array of CDF values for each row