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IGAPPFName:
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where The percent point function is the inverse of the cumulative distribution function. The cumulative distribution sums the probability from 0 to the given x value (i.e., the integral of the above function). The percent point function takes a cumulative probability value and computes the corresponding x value. The inverted gamma is the special case where the second shape parameter, c, is equal to -1.
where <p> is a number, parameter, or a variable in the range 0 to 1; <y> is a variable or a parameter (depending on what <p> is) where the computed inverted gamma ppf value is saved; <k> is a positive number, parameter, or variable that specifies the first shape parameter; <loc> is a number, parameter, or variable that defines the location parameter; <scale> is a number, parameter, or variable that defines the scale parameter; and where the <SUBSET/EXCEPT/FOR qualification> is optional. The location and scale parameters are optional.
LET Y = IGAPPF(X,1.5) LET Y = IGAPPF(X,1.5,10,2) PLOT IGAPPF(P,1.5,10,2) FOR P = 0.01 0.01 0.99
"Statistical Distributions", 2nd. Edition, Evans, Hastings, and Peacock, Wiley and Sons, 1993 (chapter 18).
. MULTIPLOT 2 2 MULTIPLOT CORNER COORDINATES 0 0 100 100 TITLE AUTOMATIC LOOP FOR K = 1 1 4 LET G1 = G(K) X1LABEL GAMMA = ^G1 PLOT IGAPPF(P,G1) FOR P = 0.05 0.01 0.95 END OF LOOP END OF MULTIPLOT
Date created: 6/5/2001 |