Serial composition of two Gotoh transducers
The composite transducer,

,
where

is the
GotohTransducer.
(See
TransducerLegend for key.)
The diagrams on this page are admittedly pretty horrendous.
My motivation for looking at these is to see if there is some way to approximate the following transducer using the simpler
GotohTransducer.
This would essentially correspond to a "renormalization" of the transducer's parameter space,
which in turn might illuminate a classic problem in statistical alignment: the derivation of convex gap penalties from an evolutionary indel model with affine gaps.
See
RenormalizedTransducerComposition for more details.
digraph G {
SS [shape=doublecircle, color=red];
EE [shape=doublecircle, color=red];
WW [shape=doubleoctagon, color=red];
WX [shape=doubleoctagon, color=red];
XW [shape=doubleoctagon, color=red];
XX [shape=doubleoctagon, color=red];
SI [shape=house, color=red];
IM [shape=house, color=red];
II [shape=house, color=red];
MI [shape=house, color=red];
MM [shape=rect, color=red];
MD [shape=invhouse, color=red];
DW [shape=invhouse, color=red];
DX [shape=invhouse, color=red];
SS->SI;SS->SW;SS->SX;
SI->SI->SW;SI->SX;
SW->IM;SW->WW;SW->XW;
SX->ID;SX->WX;SX->XX;
IM->II;IM->IW;IM->IX;
II->II;II->IW;II->IX;
IW->IM;IW->WW;IW->XW;
IX->ID;IX->WX;IX->XX;
ID->IW;ID->IX;
WW->EE;WW->MM;
WX->EE;WX->MD;
XW->EE;XW->DW;
XX->EE;XX->DX;
MM->MI;MM->MW;MM->MX;
MI->MI;MI->MW;MI->MX;
MD->MW;MD->MX;
MW->IM;MW->WW;MW->XW;
MX->ID;MX->WX;MX->XX;
DW->WW;DW->XW;
DX->WX;DX->XX;
DW->IM;
DX->ID;
ID->II;
MD->MI;
label="Serial composition of two Gotoh transducers";
}
We can also consider the jointly normalized HMM that is the composition
of the
SingletTransducer with the above composed transducer (c.f.
GotohPairHMM).
Notationally this is

,
where

is the
SingletTransducer.
This diagram assumes S/M symmetry in the
GotohTransducer and S/I symmetry in the
SingletTransducer (so e.g. "SSI" and "IMI" are the same state).
digraph G {
SSS [shape=doublecircle, color=red];
EEE [shape=doublecircle, color=red];
SSI [shape=house, color=red, label="SSI/IMI"];
SIM [shape=house, color=red, label="SIM/IIM"];
SII [shape=house, color=red, label="SII/III"];
SID [label="SID/IID"];
IMM [shape=rect, color=red];
IMD [shape=invhouse, color=red];
IDW [shape=invhouse, color=red];
IDX [shape=invhouse, color=red];
IMM->SSS;
SSS->SSI [label=d];
SSS->SIM [label=ed];
SSS->SID [label=fd];
SSS->IMM [label=eeg];
SSS->IMD [label=feg];
SSS->IDW [label=efg];
SSS->IDX [label=ffg];
SSS->EEE [label="h(e+f)(e+f)"];
SSI->SSI [label=v];
SSI->SIM [label=wd];
SSI->SID [label=xd];
SSI->IMM [label=weg];
SSI->IMD [label=xeg];
SSI->IDW [label=wfg];
SSI->IDX [label=xfg];
SSI->EEE [label="h(w+x)(w+x)"];
SIM->SII [label=d];
SIM->SIM [label=ev];
SIM->SID [label=fv];
SIM->IMM [label=ewg];
SIM->IMD [label=fwg];
SIM->IDW [label=exg];
SIM->IDX [label=fxg];
SIM->EEE [label="h(e+f)(w+x)"];
SII->SII [label=v];
SII->SIM [label=wv];
SII->SID [label=xv];
SII->IMM [label=wwg];
SII->IMD [label=xwg];
SII->IDW [label=wxg];
SII->IDX [label=xxg];
SII->EEE [label="h(w+x)(w+x)"];
SID->SII [label=p];
SID->SIM [label=qv];
SID->SID [label=rv];
SID->IMM [label=qwg];
SID->IMD [label=rwg];
SID->IDW [label=qxg];
SID->IDX [label=rxg];
SID->EEE [label="h(q+r)(w+x)"];
IMD->SSI [label=p];
IMD->SIM [label=qd];
IMD->SID [label=rd];
IMD->IMM [label=qeg];
IMD->IMD [label=reg];
IMD->IDW [label=qfg];
IMD->IDX [label=rfg];
IMD->EEE [label="h(q+r)(e+f)"];
IDW->SIM [label=p];
IDW->IMM [label=qg];
IDW->IDW [label=rg];
IDW->EEE [label="h(q+r)"];
IDX->SID [label=p];
IDX->IMD [label=qg];
IDX->IDX [label=rg];
IDX->EEE [label="h(q+r)"];
label="Serial composition of singlet & two Gotoh transducers";
}
--
IanHolmes - 28 Feb 2007