math-php
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Noncentral t-distribution https://en.wikipedia.org/wiki/Noncentral_t-distribution. More...
Public Member Functions | |
__construct (int $ν, float $μ) | |
Constructor. More... | |
pdf (float $x) | |
Probability density function. More... | |
cdf (float $x) | |
Cumulative distribution function. More... | |
mean () | |
Mean of the distribution _ /ν Γ((ν - 1)/2) E[T] = μ / - ---------— if ν > 1 √ 2 Γ(ν/2) More... | |
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inverse (float $target) | |
The Inverse CDF of the distribution. More... | |
between (float $x₁, float $x₂) | |
CDF between - probability of being between two points, x₁ and x₂ The area under a continuous distribution, that lies between two specified points. More... | |
outside (float $x₁, float $x₂) | |
CDF outside - Probability of being below x₁ and above x₂. More... | |
above (float $x) | |
CDF above - Probability of being above x to ∞ Area under a continuous distribution, that lies above a specified point. More... | |
rand () | |
Produce a random number with a particular distribution. More... | |
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__construct (... $params) | |
Constructor. More... | |
Public Attributes | |
const | PARAMETER_LIMITS |
const | SUPPORT_LIMITS |
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const | GUESS_THRESHOLD = 10 |
const | GUESS_ALLOWANCE = 8 |
Protected Attributes | |
$ν | |
$μ | |
Noncentral t-distribution https://en.wikipedia.org/wiki/Noncentral_t-distribution.
MathPHP\Probability\Distribution\Continuous\NoncentralT::__construct | ( | int | $ν, |
float | $μ | ||
) |
Constructor.
int | $ν | degrees of freedom > 0 |
float | $μ | Noncentrality parameter |
MathPHP\Probability\Distribution\Continuous\NoncentralT::cdf | ( | float | $x | ) |
Cumulative distribution function.
Fᵥ,ᵤ(x) = Fᵥ,ᵤ(x), if x ≥ 0 = 1 - Fᵥ,₋ᵤ(x) if x < 0
float | $x |
Implements MathPHP\Probability\Distribution\Continuous\ContinuousDistribution.
MathPHP\Probability\Distribution\Continuous\NoncentralT::mean | ( | ) |
Mean of the distribution _ /ν Γ((ν - 1)/2) E[T] = μ / - ---------— if ν > 1 √ 2 Γ(ν/2)
= Does not exist if ν ≤ 1
Implements MathPHP\Probability\Distribution\Continuous\ContinuousDistribution.
MathPHP\Probability\Distribution\Continuous\NoncentralT::pdf | ( | float | $x | ) |
Probability density function.
/v\ / μ²\ | - | |-1*— | / ν 3 μ²x² \ / ν + 1 1 μ²x² \ \ \2/ \ 2 / / ₁F₁| - ; - ; ------— | ₁F₁| --— ; - ; ------— | | ν * Γ(ν + 1) * e | \ 2 2 2(ν + x²)/ \ 2 2 2(ν + x²)/ | ------------------------------— * | √2*μ*x * ------------------------— + -----------------------------— | ν (ν / 2) | / ν + 1 \ / ν \ | 2 * (ν + x²) * Γ(ν / 2) | (ν + x²) * Γ| ---— | √(ν + x²) * Γ| - + 1 | | \ \ 2 / \ 2 / /
float | $x | percentile |
Implements MathPHP\Probability\Distribution\Continuous\ContinuousDistribution.
const MathPHP\Probability\Distribution\Continuous\NoncentralT::PARAMETER_LIMITS |
const MathPHP\Probability\Distribution\Continuous\NoncentralT::SUPPORT_LIMITS |