lookup

Lefthand endpoints of intervals of constancy

xgrid

Values on these intervals, of same length as <code>xgrid</code>

ygrid

Input vector of arbitrary independent variables.

Value to be returned for values of <code>x</code> that are smaller
 than <code>min(xgrid)</code>.

Given the values and lefthand endpoints for intervals of constancy,
 lookup values of the function at arbitrary values of the independent
 variable.

misc

Tools for the evaluation of interim analysis plans for sequentially
monitored trials on a survival endpoint; tools to construct efficacy and
futility boundaries, for deriving power of a sequential design at a specified
alternative, template for evaluating the performance of candidate plans at a
set of time varying alternatives. See Izmirlian, G. (2014) <doi:10.4310/SII.2014.v7.n1.a4>.

Grant Izmirlian

PwrGSD

Power in a Group Sequential Design

lookup function

<dl> <dt>xgrid</dt>
<dd>Lefthand endpoints of intervals of constancy</dd> <dt>ygrid</dt>
<dd>Values on these intervals, of same length as <code>xgrid</code></dd> <dt>x</dt>
<dd>Input vector of arbitrary independent variables.</dd> <dt>y0</dt>
<dd>Value to be returned for values of <code>x</code> that are smaller
 than <code>min(xgrid)</code>.</dd></dl>

Arguments

Grant Izmirlian &lt;izmirlian@nih.gov&gt;

Author

Lookup values for a piecewise constant function — lookup

<dl>

 <dt>xgrid</dt>
<dd>Lefthand endpoints of intervals of constancy</dd>

 <dt>ygrid</dt>
<dd>Values on these intervals, of same length as <code>xgrid</code></dd>

 <dt>x</dt>
<dd>Input vector of arbitrary independent variables.</dd>

 <dt>y0</dt>
<dd>Value to be returned for values of <code>x</code> that are smaller
 than <code>min(xgrid)</code>.</dd>

</dl>

lookup: Lookup values for a piecewise constant function

Description

Usage

Value

Arguments

Author

Examples