Triangular
Triangular distribution constructor.
Usage
var Triangular = require( '@stdlib/stats/base/dists/triangular/ctor' );
Triangular( [a, b, c] )
Returns a triangular distribution object.
var triangular = new Triangular();
var mu = triangular.mean;
// returns 0.5
By default, a = 0.0
, b = 1.0
, and c = 0.5
. To create a distribution having a different a
(minimum support), b
(maximum support), and c
(mode), provide the corresponding arguments.
var triangular = new Triangular( 2.0, 4.0, 3.5 );
var mu = triangular.mean;
// returns ~3.167
triangular
An triangular distribution object has the following properties and methods...
Writable Properties
triangular.a
Minimum support of the distribution. a
must be a number smaller than or equal to b
and c
.
var triangular = new Triangular();
var a = triangular.a;
// returns 0.0
triangular.a = 0.5;
a = triangular.a;
// returns 0.5
triangular.b
Maximum support of the distribution. b
must be a number larger than or equal to a
and c
.
var triangular = new Triangular( 2.0, 4.0, 2.5 );
var b = triangular.b;
// returns 4.0
triangular.b = 3.0;
b = triangular.b;
// returns 3.0
triangular.c
Mode of the distribution. c
must be a number larger than or equal to a
and smaller than or equal to b
.
var triangular = new Triangular( 2.0, 5.0, 4.0 );
var c = triangular.c;
// returns 4.0
triangular.c = 3.0;
c = triangular.c;
// returns 3.0
Computed Properties
Triangular.prototype.entropy
Returns the differential entropy.
var triangular = new Triangular( 4.0, 12.0, 10.0 );
var entropy = triangular.entropy;
// returns ~1.886
Triangular.prototype.kurtosis
Returns the excess kurtosis.
var triangular = new Triangular( 4.0, 12.0, 10.0 );
var kurtosis = triangular.kurtosis;
// returns -0.6
Triangular.prototype.mean
Returns the expected value.
var triangular = new Triangular( 4.0, 12.0, 10.0 );
var mu = triangular.mean;
// returns ~8.667
Triangular.prototype.median
Returns the median.
var triangular = new Triangular( 4.0, 12.0, 10.0 );
var median = triangular.median;
// returns ~8.899
Triangular.prototype.mode
Returns the mode.
var triangular = new Triangular( 4.0, 12.0, 10.0 );
var mode = triangular.mode;
// returns 10.0
Triangular.prototype.skewness
Returns the skewness.
var triangular = new Triangular( 4.0, 12.0, 10.0 );
var skewness = triangular.skewness;
// returns ~-0.422
Triangular.prototype.stdev
Returns the standard deviation.
var triangular = new Triangular( 4.0, 12.0, 10.0 );
var s = triangular.stdev;
// returns ~1.7
Triangular.prototype.variance
Returns the variance.
var triangular = new Triangular( 4.0, 12.0, 10.0 );
var s2 = triangular.variance;
// returns ~2.889
Methods
Triangular.prototype.cdf( x )
Evaluates the cumulative distribution function (CDF).
var triangular = new Triangular( 2.0, 4.0, 3.0 );
var y = triangular.cdf( 2.5 );
// returns 0.125
Triangular.prototype.logcdf( x )
Evaluates the natural logarithm of the cumulative distribution function (CDF).
var triangular = new Triangular( 2.0, 4.0, 3.0 );
var y = triangular.logcdf( 2.5 );
// returns ~-2.079
Triangular.prototype.logpdf( x )
Evaluates the natural logarithm of the probability density function (PDF).
var triangular = new Triangular( 2.0, 4.0, 3.0 );
var y = triangular.logpdf( 2.5 );
// returns ~-0.693
Triangular.prototype.pdf( x )
Evaluates the probability density function (PDF).
var triangular = new Triangular( 2.0, 4.0, 3.0 );
var y = triangular.pdf( 2.5 );
// returns 0.5
Triangular.prototype.quantile( p )
Evaluates the quantile function at probability p
.
var triangular = new Triangular( 2.0, 4.0, 3.0 );
var y = triangular.quantile( 0.5 );
// returns 3.0
y = triangular.quantile( 1.9 );
// returns NaN
Examples
var Triangular = require( '@stdlib/stats/base/dists/triangular/ctor' );
var triangular = new Triangular( 2.0, 4.0, 3.0 );
var mu = triangular.mean;
// returns 3.0
var median = triangular.median;
// returns 3.0
var s2 = triangular.variance;
// returns ~0.167
var y = triangular.cdf( 2.5 );
// returns 0.125