Incomplete gamma integral and its complement
These functions are defined by
gammaIncomplete = ( $(INTEGRATE 0, x) e-t ta-1 dt )/ $(GAMMA)(a)
gammaIncompleteCompl(a,x) = 1 - gammaIncomplete(a,x) = ($(INTEGRATE x, $(INFIN)) e-t ta-1 dt )/ $(GAMMA)(a)
In this implementation both arguments must be positive. The integral is evaluated by either a power series or continued fraction expansion, depending on the relative values of a and x.
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Incomplete gamma integral and its complement
These functions are defined by
gammaIncomplete = ( $(INTEGRATE 0, x) e-t ta-1 dt )/ $(GAMMA)(a)
gammaIncompleteCompl(a,x) = 1 - gammaIncomplete(a,x) = ($(INTEGRATE x, $(INFIN)) e-t ta-1 dt )/ $(GAMMA)(a)
In this implementation both arguments must be positive. The integral is evaluated by either a power series or continued fraction expansion, depending on the relative values of a and x.