Dataplot Vol 2 Vol 1

# TRACDF

Name:
TRACDF (LET)
Type:
Library Function
Purpose:
Compute the trapezoidal cumulative distribution function.
Description:
The trapezoidal distribution has the following cumulative distribution function:

Syntax:
LET <y> = TRACDF(<x>,<a>,<b>,<c> <d>)
<SUBSET/EXCEPT/FOR qualification>
where <x> is a variable, number, or parameter containing values in the interval (a,d);
<a> is a number, parameter, or variable that specifies the first shape parameter;
<b> is a number, parameter, or variable that specifies the second shape parameter;
<c> is a number, parameter, or variable that specifies the third shape parameter;
<d> is a number, parameter, or variable that specifies the fourth shape parameter;
<y> is a variable or a parameter (depending on what <x> is) where the computed cdf value is stored;
and where the <SUBSET/EXCEPT/FOR qualification> is optional.
Examples:
LET A = TRACDF(0.5,0,0.25,0.75,1)
LET A = TRACDF(0.5,A,B,C,D)
Default:
None
Synonyms:
None
Related Commands:
 TRAPDF = Compute the trapezoidal probability density function. TRAPPF = Compute the trapezoidal percent point function. TRIPDF = Compute the triangular probability density function. UNIPDF = Compute the uniform probability density function. SEMPDF = Compute the semi-circular probability density function. NORPDF = Compute the normal probability density function.
Reference:
"Generalized Trapezoidal Distributions", van Dorp and Kotz, Metrika, Vol. 58, Issue 1, July, 2003.
Applications:
Distributional Modeling
Implementation Date:
2004/1
Program:
```
TITLE TRAPEZOIDAL DISTRIBUTION
LET A = 0
LET B = 1
LET C = 5
LET D = 10
PLOT TRACDF(X,A,B,C,D) FOR X = A 0.1 10
```

Date created: 2/3/2004
Last updated: 2/3/2004
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