Geometric CDF
p = distfun_geocdf(x,pr) p = distfun_geocdf(x,pr,lowertail)
a matrix of doubles, the number of Bernoulli trials after which the first success occurs. x belongs to the set {0,1,2,3,......}
a matrix of doubles, the probability of success in a Bernoulli trial. pr in (0,1].
a 1-by-1 matrix of booleans, the tail (default lowertail=%t). If lowertail is true (the default), then considers P(X<=x) otherwise P(X>x).
a matrix of doubles, the probability.
Computes the cumulative distribution function of the Geometric distribution function.
Any scalar input argument is expanded to a matrix of doubles of the same size as the other input arguments.
p = distfun_geocdf(3,0.5) expected = 0.9375; //Test with x expanded, pr scalar computed = distfun_geocdf([2 3],0.33) expected = [0.699237 0.7984888]; //Test with x scalar, pr expanded computed = distfun_geocdf(3,[0.2 0.4]) expected = [0.5904 0.8704]; //Test with both the arguments expanded computed = distfun_geocdf([3 4 8],[0.5 0.8 0.2]) expected = [0.9375 0.99968 0.8657823]; //Plot the function h=scf(); x=(0:10)'; p1=distfun_geocdf(x,0.2); p2=distfun_geocdf(x,0.5); p3=distfun_geocdf(x,0.8); legendspec=["pr=0.2","pr=0.5","pr=0.8"]; distfun_plotintcdf(x,[p1,p2,p3],["r" "g" "b"],legendspec); xtitle("Geometric CDF") h.children.children(1).legend_location="in_lower_right"; // See upper tail p = distfun_geocdf(3,0.1) lt_expected = 0.3439; q = distfun_geocdf(3,0.1,%f) ut_expected = 0.6561; p+q // See accuray in the upper tail p = distfun_geocdf(100,0.5,%f) expected = 3.944305e-31 // See accuray when pr is small p = distfun_geocdf(1,1.e-20) expected = 2.e-20 | ![]() | ![]() |
http://en.wikipedia.org/wiki/Geometric_distribution