Raul, Not sure if your request was prompted by your thinking that H. was no longer available in J9, but in case it's useful erf as defined in stats/distribs/normal works on non integers.
erf 0.5 1 1.5 0.5205 0.842701 0.966105 NB. erf v error function NB. ref Abramovitz and Stegum 7.1.21 (right) erf=: (*&(%:4p_1)%^@:*:)*[:1 H. 1.5*: On Sun, 23 Jan 2022, 07:53 Raul Miller, <[email protected]> wrote: > https://www.jsoftware.com/help/dictionary/dhcapdot.htm > > Using > > H=: {{(m {{m rf %&(*/) n rf=. {{(,m) ^!.1/ i.@[}}}} n +/ .* (i.@[ ^~ > ]) % !@i.@[)"0}} > erf=: (1 H 1.5)@*: * 2p_0.5&* % ^@:*: > > or > > rf=: 1 : '(,m) ^!.1/ i.@[' NB. Rising factorial > L1=: 2 : 'm rf %&(*/) n rf' > L2=: (i.@[ ^~ ]) % !@i.@[ > H =: 2 : '(m L1 n +/ . * L2) " 0' > erf=: (1 H 1.5)@*: * 2p_0.5&* % ^@:*: > > I get > > erf 0.5 1 1.5 > | domain error > > Apparently the problem is that this version of hypergeometric can only > handle integer arguments (because L2 uses i. which requires integer > arguments). > > Does anyone know how to implement the J version 8 of erf? > > Thanks, > > -- > Raul > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
