ProportionalHazards.StratumRatio Property

ProportionalHazardsStratumRatio Property

The ratio at which a stratum is split into two strata.

Namespace: Imsl.Stat
Assembly: ImslCS (in ImslCS.dll) Version: 6.5.2.0

Syntax

public virtual double StratumRatio { get; set; }

Public Overridable Property StratumRatio As Double
	Get
	Set

public:
virtual property double StratumRatio {
	double get ();
	void set (double value);
}

abstract StratumRatio : float with get, set
override StratumRatio : float with get, set

Property Value

Type: Double
A double specifying the ratio at which a stratum is split into two strata.

Default: StratumRatio = 1000.

Remarks

Let

$r_k=\textup{exp}(z_k\hat{\beta}+w_k)$

be the observation proportionality constant, where

is the design row vector for the k-th observation and

is the optional fixed parameter specified by $x_{k,\textup{ConstantColumn}}$ . Let $r_{min}$ be the minimum value

in a stratum, where, for failed observations, the minimum is over all times less than or equal to the time of occurrence of the k-th observation. Let $r_{max}$ be the maximum value of

for the remaining observations in the group. Then, if $r_{min}$ $\gt$ value $* r_{max}$ , the observations in the group are divided into two groups at k. Set StratumRatio = -1 if no division into strata is to be made.

Reference

ProportionalHazards Class

Imsl.Stat Namespace