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Bug correction ptc_track: disable stochastic during closed orbit search … #565

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merged 3 commits into from Feb 14, 2018
Merged

Bug correction ptc_track: disable stochastic during closed orbit search … #565

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645d754
Bug correction ptc_track: disable stochastic during closed orbit sear…
piotrskowronski Feb 14, 2018
bbf2bcd
Added parameter for ptc_track defining the initial guess for the clos…
piotrskowronski Feb 14, 2018
6dfcb07
Merge remote-tracking branch 'upstream/master'
piotrskowronski Feb 14, 2018
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48 changes: 36 additions & 12 deletions doc/latexuguide/ptc-general.tex
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Expand Up @@ -90,14 +90,25 @@ \section{PTC\_CREATE\_UNIVERSE}
sector bends defining up to which order Maxwell's equation are solved
(see \cite{forest2002}~page~76-77).
The value of \texttt{SECTOR\_NMUL\_MAX} must not be smaller than
\texttt{SECTOR\_NMUL} otherwise \madx stops with an error. \\ (Default:~10)
\texttt{SECTOR\_NMUL} otherwise \madx stops with an error.
If a negative value is passed than it is identified automatically
by scanning the currently selected sequence.
\\ (Default:~-1)

\ttitem{SECTOR\_NMUL} a global variable in PTC needed for exact
sector bends defining up to which order the multipole are included in
solving Maxwell's equation up to order \texttt{SECTOR\_NMUL\_MAX}.
Multipoles of order N with N $>$ \texttt{SECTOR\_NMUL} and N $\leq$
\texttt{SECTOR\_NMUL\_MAX} are treated similar to \textit{SixTrack}. \\
(Default:~10)
\texttt{SECTOR\_NMUL\_MAX} are treated similar to \textit{SixTrack}.
If a negative value of \\
\texttt{SECTOR\_NMUL\_MAX} is passed than it is also identified automatically.
However, if multipolar parameters of the bends are to be modified inside the PTC universe,
for example with \texttt{PTC\_READ\_ERRORS},
than this parameter needs to be set to a corresponding value.
Please note that using large values (above 10) slows down the computations,
so the smallest required value should be used.
\\
(Default:-1)

\ttitem{NTPSA} invokes the Differential Algebra (DA) package
written in C++ and kindly provided by Lingyun Yang (lyyang@lbl.gov). \\
Expand Down Expand Up @@ -221,24 +232,23 @@ \section{PTC\_SETSWITCH}

\madbox{
PTC\_SETSWITCH, \=DEBUGLEVEL=integer, \\
\>MAXACCELERATION=logical,\\
\>EXACT\_MIS=logical,\\
\>TOTALPATH=logical,\\
\>RADIATION=logical,\\
\>ENVELOPE=logical,\\
\>STOCHASTIC=logical,\\
\>MODULATION=logical,\\
\>FRINGE=logical,\\
\>TIME=logical;
\>TIME=logical,\\
\>SEED=integer,\\
\>MAXACCELERATION=logical;
}

The command parameters and switches are:
\begin{madlist}
\ttitem{DEBUGLEVEL} (Default: 1)\\
Sets the level of debugging printout: 0 prints none, 4 prints everything

\ttitem{MAXACCELERATION} (Default: true)\\
Switch to set cavities phases so the reference orbit is always on
the crest, i.e. gains max energy

\ttitem{EXACT\_MIS} (Default: false)\\
Switch ensures exact misalignment treatment.

Expand Down Expand Up @@ -279,7 +289,7 @@ \section{PTC\_SETSWITCH}
The emission is calculated during map tracking therefore
\texttt{PTC\_TWISS} or \texttt{PTC\_NORMAL}
needs to be invoked before launching the tracking
(also with \ttitem{RADIATION}, \ttitem{ENVELOPE} and \ttitem{STOCHASTIC} set to true).
(also with \texttt{RADIATION}, \texttt{ENVELOPE} and \texttt{STOCHASTIC} set to true).
Every tracked ray will receive the same stochastic kicks.

\ttitem{MODULATION} (Default: false)\\
Expand Down Expand Up @@ -318,14 +328,23 @@ \section{PTC\_SETSWITCH}

\textbf{Note:} at small energy ($\beta_0 << 1$),
momentum-dependent variables like dispersion will depend strongly on
the choice of the logical input variable \ttitem{TIME}. In fact, the
the choice of the logical input variable \texttt{TIME}. In fact, the
derivative ($\frac{\partial}{\partial \delta_p}$) and
($\frac{\partial}{\partial p_t}$) are different by the
factor $\beta_0$. One would therefore typically choose
the option \ttitem{TIME=false}, which sets the fifth variable to
the option \texttt{TIME=false}, which sets the fifth variable to
the relative momentum deviation $\delta_p$.


\ttitem{SEED} (Default: 123456789)\\
Sets the seed of PTC random number generator,
which is independent from the MADX generators.

\ttitem{MAXACCELERATION} (Default: true)\\
Switch to set cavities phases so the reference orbit is always on
the crest, i.e. gains max energy.


\end{madlist}

%% \textbf{PROGRAMMERS MANUAL}
Expand Down Expand Up @@ -382,6 +401,11 @@ \section{PTC\_READ\_ERRORS}
(Default:~false)
\end{madlist}

\textbf{Note:}\\
For calculations with exact flag set to true,
\texttt{SECTOR\_NMUL} parameter of \texttt{PTC\_CREATE\_UNIVERSE}
needs to be set to a value bigger than the highest order of an error in bending magnets.

\textbf{Note:}\\
Because of the way the table is read in memory, a warning will always be
issued by default in the form:
Expand Down
4 changes: 4 additions & 0 deletions doc/latexuguide/ptc-track.tex
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Expand Up @@ -178,6 +178,7 @@ \section{PTC\_TRACK}
\>MAXAPER=real\_array, \\
\>NORM\_NO=integer, NORM\_OUT=logical, \\
\>FILE[=string], EXTENSION=string, FFILE=integer, \\
\>X=real, PX=real, Y=real, PY=real, T=real, PT=real, \\
\>RADIATION=logical, RADIATION\_MODEL1=logical, \\
\>RADIATION\_ENERGY\_LOSS=logical, \\
\>RADIATION\_QUAD=logical, \\
Expand Down Expand Up @@ -286,6 +287,9 @@ \section{PTC\_TRACK}
\ttitem{FFILE} defines the periodicity \texttt{n} of the printout:
coordinates are printed every n turns. \\ (Default: 1)

\ttitem{X, PX, Y, PY, T, PT} the initial
\hyperref[subsec:tables-canon]{canonical} coordinates for the closed orbit search. \\ (Default: 0.0) \\

\ttitem{RADIATION}\label{opt:radiation} a logical flag to turn on
the synchrotron radiation calculated by an internal procedure of
\ptc. \\
Expand Down
3 changes: 3 additions & 0 deletions src/mad_dict.c
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Expand Up @@ -747,6 +747,9 @@ const char *const_command_def =
"ffile = [i, 1], "
"rootntuple = [l, false, true], "/*writes all the tracks in ROOT NTuple -> works only if program is dynamically linked and RPLOT plugin is present */
"maxaper= [r, {0.1, 0.01, 0.1, 0.01, 1., 0.1}], "
"x = [r, 0], px = [r, 0], " /*initial guess for closed orbit search*/
"y = [r, 0], py = [r, 0], "
"t = [r, 0], pt = [r, 0], "
"norm_out = [l, false, true], "
"norm_no = [i, 1]; "
" "
Expand Down
48 changes: 38 additions & 10 deletions src/madx_ptc_track_run.f90
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Expand Up @@ -296,13 +296,18 @@ SUBROUTINE ptc_track_run(max_obs)
ENDIF warn_coordinate_system_changed

! initialize the closed orbit coordinates at START of the ring
x_coord_co(:)=zero
if (ptc_track_debug) then
print *, " x_coord_co(:)=zero = ",x_coord_co
endif

! Closed_orbit_at_START:
IF(closed_orbit) CALL Find_Closed_Orbit ! Calculates x_coord_co(1:6)
IF(closed_orbit) then
CALL Find_Closed_Orbit ! Calculates x_coord_co(1:6)

if ( .not. check_stable) then
write(whymsg,*) 'DA got unstable during closed orbit search: PTC msg: ',messagelost(:len_trim(messagelost))
call fort_warn('ptc_track: ',whymsg(:len_trim(whymsg)))
call seterrorflag(10,"ptc_track ",whymsg);
return
endif

endif

! needed to transfrom coordinates in case closed_orbit=true AND element_by_element=false
Normal_forms: IF(closed_orbit) THEN !-----------------------!
Expand Down Expand Up @@ -802,14 +807,21 @@ END SUBROUTINE Call_my_state_and_update_states
SUBROUTINE Find_Closed_Orbit
! USE madx_ptc_module, ONLY: dp, zero, find_orbit, my_ring,default
implicit none
logical isstochastic
!
!====================================================================!
! initialize the closed orbit coordinates !
! x0(:)=zero !
x_coord_co(:)=zero !

x_coord_co(1)=get_value('ptc_track ','x ')
x_coord_co(2)=get_value('ptc_track ','px ')
x_coord_co(3)=get_value('ptc_track ','y ')
x_coord_co(4)=get_value('ptc_track ','py ')
x_coord_co(6)=-get_value('ptc_track ','t ') ! swap of t sign
x_coord_co(5)=get_value('ptc_track ','pt ')

if (ptc_track_debug) THEN !---------------------------! !
print *, " x_coord_co(:)=zero = " ! !
CALL write_closed_orbit(nvariables,x_coord_co) ! !
print *, "Start point for closed orbit search: " ! !
CALL write_closed_orbit(nvariables,x_coord_co) ! !
end if !----------------------------------------------! !
! !
if(nvariables.ge.5) THEN !------------------------! !
Expand All @@ -825,17 +837,33 @@ SUBROUTINE Find_Closed_Orbit
print *, " if(icase.eq.5) ,x_coord_co(5)=deltap" ! !
print *, " ,x_coord_co(5),deltap=", & ! !
x_coord_co(5),deltap ! !
global_verbose = .true.
end if !--------------------------------------------! !
! !
if(closed_orbit) then !------------------------------------! !

! temporarly disbale stochastic, otherwise the search is doomed to fail
isstochastic = MYSTATE%stochastic
MYSTATE%stochastic = .false.

CALL FIND_ORBIT_x(my_ring,x_coord_co,MYSTATE,c_1d_7,fibre1=1) !
! call find_orbit(my_ring,x_coord_co,1,MYSTATE,c_1d_7) !

if ( .not. check_stable) then
! the routine which calls this function should also
! check the flag and report the eventual error
return
endif

MYSTATE%stochastic = isstochastic

print*,"===== ptc_track ============================" ! !
CALL write_closed_orbit(nvariables,x_coord_co) ! !
print*,"============================================" ! !
endif !---------------------------------------------------! !
! !
if (ptc_track_debug) then
global_verbose = .false.
print*,"After closed_orbit"; print *; !
endif !
! !
Expand Down