
GL4PPFName:
The general form of the type 4 generalized logistic probability density function can be obtained by replacing x in the above formula with (xloc)/scale. The generalized logistic type 4 cumulative distribution function is computed by numerically integrating the probability density function. Dataplot uses the DQAGI routine from the Slatec library to perform the integration. The percent point function is then computed by numerically inverting the cumulative distribution function.
<SUBSET/EXCEPT/FOR qualification> where <x> is a variable, number or parameter; <p> is a number or parameter that specifies the value of the first shape parameter; <q> is a number or parameter that specifies the value of the second shape parameter; <loc> is a number or parameter that specifies the value of the location parameter; <scale> is a number or parameter that specifies the value of the scale parameter; <y> is a variable or a parameter (depending on what <x> is) where the computed generalized logistic type 3 ppf value is stored; and where the <SUBSET/EXCEPT/FOR qualification> is optional. The location and scale parameters are optional.
LET X2 = GL4PPF(X1,P,Q) PLOT GL4PPF(X,P,Q) FOR X = 5 0.01 5
LET PA = DATA 0.5 1 2 LET QA = DATA 0.5 1 2 MULTIPLOT 3 3 MULTIPLOT CORNER COORDINATES 0 0 100 95 MULTIPLOT SCALE FACTOR 3 LABEL CASE ASIS TITLE CASE ASIS TITLE DISPLACEMENT 2 Y1LABEL X X1LABEL Probability X1LABEL DISPLACEMENT 14 Y1LABEL DISPLACEMENT 15 . LOOP FOR K = 1 1 3 LET P = PA(K) LOOP FOR L = 1 1 3 LET Q = QA(L) TITLE P = ^P, Q = ^Q PLOT GL4PPF(X,P,Q) FOR X = 0.01 0.01 0.99 END OF LOOP END OF LOOP END OF MULTIPLOT CASE ASIS MOVE 50 97 JUSTIFICATION CENTER TEXT Generalized Logistic Type 4 PPF's
Date created: 3/27/2006 