(49g) (50g) STAT Inv as user key — Inv.UTPC, Inv.UTPF, Inv.UTPN, Inv.UTPT - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Software Libraries (/forum-10.html) +--- Forum: General Software Library (/forum-13.html) +--- Thread: (49g) (50g) STAT Inv as user key — Inv.UTPC, Inv.UTPF, Inv.UTPN, Inv.UTPT (/thread-16097.html) (49g) (50g) STAT Inv as user key — Inv.UTPC, Inv.UTPF, Inv.UTPN, Inv.UTPT - Gil - 12-31-2020 11:10 AM The HP49-50G calculators have no built-in inverse function of UTPC, UTPF, UTPN, UTPTN. It's sometimes handy to dispose of them instantaneously, without having to write a "root-solver" from scratch. Here are the "missing" build-in inverse functions accessible through key-user assigned letters C, F, N and T: LS-User C (C for Chi); LS-User F (C for Fisher); LS-User N (C for Normal); LS-User T (C for sTudent). The arguments are basically in the same order as in the original build-in functions UTPC, UTPF, UTPN, UTPTN, with the exception always — of course — of the last argument, that should be the upper-tail probability (for the reverse function), and not the x.Value of the original function. Note that the arguments can be entered in two ways: - {a b u.PROB}, i. e. with { }, when a and b are new; - or u.PROB only, directly in the stack, without any { }, when a and b repeat themselves. Example for the Normal distribution: 1st calculation Mean: 10 Variance: 5 Probability on the right: 2.5% X.N? How to procede: {10 5 0.025} LS-User N (N like Normal) Solution in the stack: {Mean: 10 Var: 5 u.PROB: 0.025} 14.3826... 2nd calculation Now only the probability changes. Mean, like before : 10 Variance, like before : 5 Probability on the right: 5% X.N? How to procede: No need to enter the cumbersome {10 5 0.05}. Just put directly 0.05 in the stack, without { }, i. e. the changed, new probability. LS-User N (N like Normal). Solution in the stack: {Mean: 10 Var: 5 u.PROB: 0.05} 13.6780... Here below are the codes for the key-assignments keys. For Chi: \<< DUP TYPE 5 == IF THEN OBJ\-> DROP 'u.PROB' STO 'lib' STO ELSE 'u.PROB' STO END lib "lib" \->TAG u.PROB "u.PROB" \->TAG 2 \->LIST \<< lib x.C UTPC u.PROB - \>> 'x.C' 2 ROOT "x.C" \->TAG \>> 13.1 ASN (13 = line 1, column 3, for letter C of Chi) For F: \<< DUP TYPE 5 == IF THEN OBJ\-> DROP 'u.PROB' STO 'lib2' STO 'lib1' STO ELSE 'u.PROB' STO END lib1 "lib1" \->TAG lib2 "lib2" \->TAG u.PROB "u.PROB" \->TAG 3 \->LIST \<< lib1 lib2 x.F UTPF u.PROB - \>> 'x.F' 2 ROOT "x.F" \->TAG \>> 16.1 ASN (16 = line 1, column 6, for letter F of Fisher) For N: \<< DUP TYPE 5 == IF THEN OBJ\-> DROP 'u.PROB' STO 'vv' STO '\Gm\Gm' STO ELSE 'u.PROB' STO END \Gm\Gm "\Gm\Gm" \->TAG vv "vv" \->TAG u.PROB "u.PROB" \->TAG 3 \->LIST \<< \Gm\Gm vv x.N UTPN u.PROB - \>> 'x.N' 2 ROOT "x.N" \->TAG \>> 42.1 ASN (4 = line 4, column 2, for letter N of Normal) For sTudent: \<< DUP TYPE 5 == IF THEN OBJ\-> DROP 'u.PROB' STO 'lib' STO ELSE 'u.PROB' STO END lib "lib" \->TAG u.PROB "u.PROB" \->TAG 2 \->LIST \<< lib x.t UTPT u.PROB - \>> 'x.t' 2 ROOT "x.t" \->TAG \>> 64.1 ASN (64 = line 6, column 4, for letter T of sTudent). That's it. Regards, Gil