# Copyright (c) 2002-08 Peter Guntert. All rights reserved.
## 7MACROS: vtfmin - CYANA macro
##
## Parameters: levels=<string>                (default: <all levels>)
##             steps=<string>                 (default: 150,400)
##             flatsteps=<string>             (default: 50,100)
##             tf
##
## Performs a standard variable target function minimization (Guntert et
## al., 1991a) starting at minimization level L1 and ending at minimization
## level L2.
## At each of the lower levels (i.e. those below L2) N1 minimization steps
## are performed, the minimization is stopped if n1 steps failed to decrease
## the target function by at least 1%, and the steric repulsion is considered
## only for the heavy atoms. The weight for steric lower limits is 0.2.
## At minimization level L2 three times N2 minimization steps are performed,
## the minimization is stopped if n2 steps failed to decrease the target
## function by at least 1%, and the steric repulsion is considered for all
## atoms. The weight for steric lower limits is 0.2 for the first N2
## minimization steps, then it is increased to 0.6 for the following N2
## minimization steps, and to 2.0 for the final N2 minimization steps.
## If the option tf (and none of the other parameters) is given, the final
## target function value is calculated, without performing any minimization.

var l nl p np echo t0

syntax $macro:levels=*=0,${rnum(nr)-rnum(1)} steps=*=150,400 flatsteps=*=50,100 tf

echo := off
t0=cputime

if (length('levels').eq.1) levels:=$levels,$levels
levels(1)=$levels(1)
levels(2)=$levels(2)
steps(1)=$steps(1)
steps(2)=$steps(2)
flatsteps(1)=$flatsteps(1)
flatsteps(2)=$flatsteps(2)

if (tf) then
  mr=rnum(nr)-rnum(1)
  levels(1)=mr; levels(2)=mr; steps(1)=0; steps(2)=0
end if
unset tf

print "    Minimization (standard strategy):" level=normal
print "     lev    upper    lower        vdw   angle target funct. |grad| \#up   \#f stop" level=normal
print "            \# act    \# act     \#  act   \# act  begin    end    end" level=normal

if (steps(1).gt.0) then
  atom set HYDROGEN radius=-1.0 info=none
  atom set HBOUND radius=radius+0.15 info=none
  weight_vdw=0.2
  p = -10; np = 0
  do l levels(1) levels(2)
    if (l.le.10 .or. l.ge.p+2) then
      nl = nlevel(l)
      if (l.ge.p+10 .or. nl.ge.np+5 .or. \
          (nl.ge.np+2 .and. nlevel(min(l+1,levels(2))).gt.np+5)) then
        level=l
        minimize steps(1) flat=$flatsteps(1)
        p = l; np = nl
      end if
    end if
  end do
end if

atom set * radius=* info=none
level=levels(2)
if (steps(2).gt.0) then
  weight_vdw=0.2
  minimize steps(2) flat=$flatsteps(2)
  weight_vdw=0.6
  minimize steps(2) flat=$flatsteps(2)
end if
weight_vdw=2.0
minimize steps(2) flat=$flatsteps(2)

print "    Structure minimized in $nint(cputime-t0) s, f = $tf."