copy_plot.i

/* Functions to copy/save/load Yorick plot
 *
 *
 * Author: Bastien Aracil
 * Written 2003
 * last revision/addition: 2005 Jan 28
 *
 *  Main functions:
 *  ---------------
 *
 *  copy_win   : copy all the graphical elements from one window to another
 *  save_plot  : save a plot in a ".pdb" file
 *  load_plot  : load a plot from a file previously saved with save_plot
 *
 *  Internally used functions:
 *  --------------------------
 *
 *  replot_all     : same as copy_win but do not copy the style of the window
 *  replot_one_sys : copy one system of a window to another system of
 *                   the same or another window
 *  reshape_prop   : convert the result of plq() to a more usefull form.
 *  replot         : replot an element from its plq() properties
 *  reshape_XYZ    : same as reshape but only for the graphical element
 *                   plotted with XYZ (called by reshape)
 *  replot_XYZ     : same as reshape but only for the graphical element
 *                   plotted with XYZ (called by replot)
 *  decomp_prop    : put *plq(n)(i) in prop_i
 *  get_nb_sys     : return the numbero of systems in a window
 *  get_color      : transform color to rgb encoding
 *
 * Copyright (c) 2005, Bastien Aracil
 *
 * This program is free software; you can redistribute it and/or  modify it
 * under the terms of the GNU General Public License  as  published  by the
 * Free Software Foundation; either version 2 of the License,  or  (at your
 * option) any later version.
 *
 * This program is distributed in the hope  that  it  will  be  useful, but
 * WITHOUT  ANY   WARRANTY;   without   even   the   implied   warranty  of
 * MERCHANTABILITY or  FITNESS  FOR  A  PARTICULAR  PURPOSE.   See  the GNU
 * General Public License for more details (to receive a  copy  of  the GNU
 * General Public License, write to the Free Software Foundation, Inc., 675
 * Mass Ave, Cambridge, MA 02139, USA).
 *
 *
 */   

if(is_func(autoload)!=2) {
  require,"style.i";
  require,"pdb_utils.i";
}

func copy_win(wsrc,wout,lmt=,clear=,pal=)
/* DOCUMENT copy_win,window_source,window_target
     Copy the style and the graphic elements of window WINDOW_SOURCE to
     window WINDOW_TARGET
   KEYWORDS: lmt=   if set, copy also the limits (the default)
             clear= if set, erase the window before copying (the default)
             pal=   if set, copy the palette too (the default)
   SEE ALSO:replot_all,replot_one_sys
 */
{
  local a,b,c,d;
  local red,green,blue;
  if(is_void(clear)) clear=1;
  if(is_void(pal)) pal=1;
  wbck=get_selected_system();

  window,wsrc;
  get_style,a,b,c,d;
  palette,red,green,blue,query=1;

  window,wout;
  set_style,a,b,c,d;
  if(clear) fma;
  if(pal&&is_array(red)) palette,red,green,blue;

  replot_all,wsrc,wout,lmt=lmt;

  set_selected_system,wbck;
}


func replot_all(wsrc,wout,lmt=)
/* DOCUMENT replot_all(window_source,window_target)
     Copy graphical elements of all systems (but not the style)
     of window window_source to window_target
   KEYWORDS: lmt : if set, copy also the limits (the default)
   SEE ALSO: copy_win,replot_one_sys
 */
{

  nbsin =get_nb_sys(wsrc);
  nbsout=get_nb_sys(wout);
  if(nbsin!=nbsout) error,"The two windows have not the same number of systems !!";

  wbck=get_selected_system();

  for(i=0;i<=nbsin;i++)
    replot_one_sys,wsrc,i,wout,i,lmt=lmt;
  window,wout;redraw;

  set_selected_system,wbck;
}


func replot_one_sys(wsrc,sin,wout,sout,lmt=)
/* DOCUMENT replot_one_sys(window_source,sys_source,winow_target,system_target)
   Copy all the graphical elements of the system sys_source
   of window_source to the system sys_target of window window_target

   KEYWORDS: lmt : if set, copy also the limits (the default)

   SEE ALSO:copy_win,replot_all
 */
{

  if(is_void(lmt)) lmt=1;
  wbck = set_selected_system([wsrc,sin]);

  lmtin=limits();
  nbobj=numberof(plq());

  window,wout;
  plsys,sout;

  if(lmt) limits,lmtin;
  for(i=1;i<=nbobj;i++)
    {
      window,wsrc;
      plsys,sin;
      prop=plq(i);
      window,wout;
      plsys,sout;
      replot,prop;
    }
  plsys,old_sout;
  window,wsrc;
  plsys,old_sin;
}


func save_plot(fstrm,wsrc,pal=)
/* DOCUMENT save_plot,fstrm,win,pal=
   -or- grp = save_plot(win,pal=)
   Save Yorick plot of window win in fstrm, which may be a filename, file
   stream, or empty oxy group object. If called as a function, will return an
   oxy group object. The plot can be reloaded with load_plot.

   KEYWORDS: pal= : save the palette if any in the file (the default)
   
   EXAMPLE:
   window,0;
   pli,random(100,100);
   pltitle,"Random array";
   limits,20,60,10,70;
   plt,"Zoom In",40,40,tosys=1,color="yellow",height=18;
   save_plot,"rand_array.gdb",0;
   load_plot,"rand_array.gdb",1;
   
   SEE ALSO: load_plot,copy_win
 */
{
  local a,b,c,d,x,y,z;
  local x0,x1,y0,y1,txt;
  local ireg;
  local p1,p2,p3,p4,p5;
  local rp,gp,bp;

  if(is_void(pal)) pal=1;

  autoclose=0;
  if(!am_subroutine()) {
    wrsc=fstrm;
    fstrm=save();
  } else if(is_string(fstrm)) {
    fstrm=createb(fstrm);
    autoclose=1;
  }
  old_win=current_window();
  if(old_win>=0) old_sys=plsys();
  window,wsrc;
  get_style,a,b,c,d;
  save,fstrm,"getstyle_p1",a;
  save,fstrm,"getstyle_p2",b;
  save,fstrm,"getstyle_p3",c;
  save,fstrm,"getstyle_p4",d;

  palette,rp,gp,bp,query=1;
  if(!is_void(rp)&&pal) {
    rgb_pal=long(rp)+(long(gp)<<8)+(long(bp)<<16);
    save,fstrm,"palette",rgb_pal;
  }

  nbsys=get_nb_sys(wsrc);
  for(i=0;i<=nbsys;i++)
    {
      plsys,i;
      lmt=limits();
      nbobj=numberof(plq());
      save,fstrm,swrite(format="system_%d",i),i;
      save,fstrm,swrite(format="limits_%d",i),lmt;
      for(j=1;j<=nbobj;j++)
        {
          prop=plq(j);
          decomp_prop,prop,p1,p2,p3,p4,p5;
          save,fstrm,swrite(format="prop1_%d_%d",i,j),(is_void(p1)?"dummy":p1);
          save,fstrm,swrite(format="prop2_%d_%d",i,j),(is_void(p2)?"dummy":p2);
          save,fstrm,swrite(format="prop3_%d_%d",i,j),(is_void(p3)?"dummy":p3);
          save,fstrm,swrite(format="prop4_%d_%d",i,j),(is_void(p4)?"dummy":p4);

          rslt=reshape_prop(prop);
          save,fstrm,swrite(format="prop5_%d_%d",i,j),(is_void(rslt)?"dummy":rslt);
        }
    }
  if(autoclose) close,fstrm;
  if(old_win>=0)
    {
      window,old_win;
      plsys,old_sys;
    }
  if(!am_subroutine()) return fstrm;
}


func load_plot(fstrm,wout,clear=,lmt=,pal=,style=,systems=)
/* DOCUMENT load_plot,fstrm,wout,clear=,lmt=,pal=,style=,systems=
   Load Yorick plot from fstrm (which may be a filename, file stream, or empty
   oxy group object) and plot in wout. The plot have to be saved with
   save_plot.

   EXAMPLE:
   window,0;
   pli,random(100,100);
   pltitle,"Random array";
   limits,20,60,10,70;
   plt,"Zoom In",40,40,tosys=1,color="yellow",height=18;
   save_plot,"rand_array.gdb",0;
   load_plot,"rand_array.gdb",1;

   KEYWORDS: lmt=   if set (default), restore also the
                    limits
             clear= if set (default) erase the window
                    before loading
             pal=   use the palette saved in the file if any (the default)
             style= use the style saved in the file if any (the default)
             systems= set to an array of system numbers to only load those
                    systems; all systems specified must exist in plot being
                    loaded
   
   SEE ALSO: save_plot,copy_win
 */
{
  if(is_void(clear)) clear=1;
  if(is_void(  lmt)) lmt=1;
  if(is_void(  pal)) pal=1;
  if(is_void(style)) style=1;

  autoclose=0;
  if(is_string(fstrm)) {
    fstrm=openb(fstrm);
    autoclose=1;
  }
  old_win=current_window();
  if(old_win>=0) old_sys=plsys();

  window,wout;
  if(style)
    set_style,fstrm.getstyle_p1,fstrm.getstyle_p2,fstrm.getstyle_p3,fstrm.getstyle_p4;
  if(clear) fma;
  names=is_stream(fstrm) ? *get_vars(fstrm)(1) : fstrm(*,);

  palette_is_present=anyof(names=="palette");
  if(palette_is_present&&pal) {
    rgb=fstrm.palette;
    palette,char(rgb&0x0000FF),char((rgb&0x00FF00)>>8),char((rgb&0xFF0000)>>16);
  }
  
  nnames=numberof(names);
  idx=4+palette_is_present;
  skip=0;
  while(++idx<=nnames)
    {
      if(strmatch(names(idx),"system_"))
        {
          sys=get_member(fstrm,names(idx));
          if(!is_void(systems)) {
            skip=0;
            if(noneof(sys==systems)) {
              skip=1;
              continue;
            }
          }
          plsys,sys;
          limits;
          continue;
        }
      if(strmatch(names(idx),"limits_"))
        {
          if(skip) continue;
          if(lmt) limits,get_member(fstrm,names(idx));
          continue;
        }

      if(strmatch(names(idx),"prop1_"))
        {
          if(skip) {
            idx += 4;
            continue;
          }
          p1  =get_member(fstrm,names(idx));
          p2  =get_member(fstrm,names(++idx));
          p3  =get_member(fstrm,names(++idx));
          p4  =get_member(fstrm,names(++idx));
          rslt=get_member(fstrm,names(++idx));
          
          replot,p1,p2,p3,p4,rslt;
          continue;
        }
      write,format="[WARNING] Unknown variable flag %s !!\n",names(idx);
    }
  if(autoclose) close,fstrm;
  redraw;
  if(old_win>=0)
    {
      window,old_win;
      plsys,old_sys;
    }
}


func reshape_prop(prop)
/* DOCUMENT reshape_prop(prop)
     Return an array of pointers that point to the data useful for
     drawing the graphical element. The size of the array depend
     of the graphical type, and the order of the pointers is the
     same than the one of the plq() fifth element.
 */
{
  aig=(*prop(1))(1);
  if(aig==1)      return reshape_plg(prop);
  else if(aig==2) return reshape_pldj(prop);
  else if(aig==3) return reshape_plt(prop);
  else if(aig==4) return reshape_plm(prop);
  else if(aig==5) return reshape_plf(prop);
  else if(aig==6) return reshape_plv(prop);
  else if(aig==7) return reshape_plc(prop);
  else if(aig==8) return reshape_pli(prop);
  else if(aig==9) return reshape_plfp(prop);
  else if(aig!=0) error,"Unknown graphical element !!";
}


func replot(p1,p2,p3,p4,rslt)
/* DOCUMENT replot(prop)
            replot(p1,p2,p3,p4,rslt)
   Replot a graphical element with its plq properties.
   prop is the array return by plq(i). then replot(plq(i))
   will replot the graphical element i.
     
   SEE ALSO: copy_win,replot_all,replot_one_sys
 */
{
  if(is_void(p2)||is_void(p3)||is_void(p4)||is_void(rslt))
    {
      aig=(*prop(1))(1);
      p1=*prop(1);
      p2=*prop(2);
      p3=*prop(3);
      p4=*prop(4);
      rslt=reshape_prop(prop);
    }
  else
    aig=p1(1);
  if(aig==1)      replot_plg ,p1,p2,p3,p4,rslt;
  else if(aig==2) replot_pldj,p1,p2,p3,p4,rslt;
  else if(aig==3) replot_plt ,p1,p2,p3,p4,rslt;
  else if(aig==4) replot_plm ,p1,p2,p3,p4,rslt;
  else if(aig==5) replot_plf ,p1,p2,p3,p4,rslt;
  else if(aig==6) replot_plv ,p1,p2,p3,p4,rslt;
  else if(aig==7) replot_plc ,p1,p2,p3,p4,rslt;
  else if(aig==8) replot_pli ,p1,p2,p3,p4,rslt;
  else if(aig==9) replot_plfp,p1,p2,p3,p4,rslt;
  else if(aig!=0) error,"Unknown graphical element !!";
}

func reshape_plg(prop)
/* DOCUMENT reshape_plg(prop)
   Return [&x,&y], where x and y are the array used for the plot (plg,y,x).
     
   SEE ALSO: reshape_prop
 */
{
  local y,x;
  local p1,p2,p3,p4,p5;
  decomp_prop,prop,p1,p2,p3,p4,p5;
  if(p1(1)!=1) error,"Bad properties !!";
  adx=p5(2);reshape,x,adx,double,[1,p5(1)];
  ady=p5(3);reshape,y,ady,double,[1,p5(1)];
  return [&x,&y];
}

func replot_plg(p1,p2,p3,p4,rslt)
/* DOCUMENT replot_plg(prop)
   Same as replot but only for plg graphical elements
   SEE ALSO: replot
 */
{
  if(p1(1)!=1) error,"Bad properties !!";

  plg,*rslt(2),*rslt(1),hide=p1(2),legend=p2,
    color= get_color(p3(1)),type=p3(2),marks= p3(3),
    mcolor=get_color(p3(4)),marker=p3(5),rays=p3(6),
    closed=p3(7),smooth=p3(8),width= p4(1),msize=p4(2),
    mspace=p4(3),rspace=p4(4),rphase=p4(5),arrowl=p4(6),arroww=p4(7);
}


func reshape_pldj(prop)
{
  local x0,y0,x1,y1;
  local p1,p2,p3,p4,p5;
  decomp_prop,prop,p1,p2,p3,p4,p5;
  if(p1(1)!=2) error,"Bad properties !!";
  adx0=p5(2);reshape,x0,adx0,double,[1,p5(1)];
  ady0=p5(3);reshape,y0,ady0,double,[1,p5(1)];
  adx1=p5(4);reshape,x1,adx1,double,[1,p5(1)];
  ady1=p5(5);reshape,y1,ady1,double,[1,p5(1)];
  return [&x0,&y0,&x1,&y1];
}

func replot_pldj(p1,p2,p3,p4,rslt)
/* DOCUMENT replot_pldj(prop)
   Same as replot but only for pldj graphical elements
   SEE ALSO: replot
 */
{
  if(p1(1)!=2) error,"Bad properties !!";
  pldj,*rslt(1),*rslt(2),*rslt(3),*rslt(4),hide=p1(2),legend=p2,
    color= get_color(p3(1)),type=p3(2),
    width= p4(1);
}

func reshape_plt(prop)
{
  local txt;
  local p1,p2,p3,p4,p5;
  decomp_prop,prop,p1,p2,p3,p4,p5;
  if(p1(1)!=3) error,"Bad properties !!";
  adt=p5(2);reshape,txt,adt,char,[1,p5(1)];
  return [&txt];
}


func replot_plt(p1,p2,p3,p4,rslt)
/* DOCUMENT replot_plt(prop)
   Same as replot but only for plt graphical elements
   SEE ALSO: replot
 */
{
  if(p1(1)!=3) error,"Bad properties !!";
  plt,string(rslt(1)),p4(2),p4(3),hide=p1(2),legend=p2,tosys=plsys(),
    color= get_color(p3(1)),font=p3(2),orient= p3(3),justify=p3(4),opaque=p3(5),
    height= p4(1);
}

func reshape_plm(prop)
{
  local p1,p2,p3,p4,p5;
  local x,y,ireg;
  decomp_prop,prop,p1,p2,p3,p4,p5;
  if(p1(1)!=4) error,"Bad properties !!";
  adx=p5(3);reshape,x,adx,double,[2,p5(1),p5(2)];
  ady=p5(4);reshape,y,ady,double,[2,p5(1),p5(2)];
  adi=p5(5);reshape,ireg,adi,int,[2,p5(1),p5(2)];
  return [&x,&y,&ireg];
}

func replot_plm(p1,p2,p3,p4,rlst)
/* DOCUMENT replot_plm(prop)
   Same as replot but only for plm graphical elements
   SEE ALSO: replot
 */
{
  if(p1(1)!=4) error,"Bad properties !!";
  plm,*rslt(2),*rslt(1),*rslt(3),legend=p2,hide=p1(2),
    color=get_color(p3(1)),type=p3(2),region=p3(3),
    boundary=p3(4),inhibit=p3(5),width=p4(1);
}

func reshape_plf(prop)
{
  local p1,p2,p3,p4,p5;
  local z,y,x,ireg;
  decomp_prop,prop,p1,p2,p3,p4,p5;
  if(p1(1)!=5) error,"Bad properties !!";
  adx=p5(3);reshape,x,adx,double,[2,p5(1),p5(2)];
  ady=p5(4);reshape,y,ady,double,[2,p5(1),p5(2)];
  adi=p5(5);reshape,ireg,adi,double,[2,p5(1),p5(2)];
  adc=p5(6);
  if(p3(4))
    reshape,z,adc,char,[3,3,p5(1)-1,p5(2)-1];
  else
    reshape,z,adc,char,[2,p5(1)-1,p5(2)-1];
  return [&x,&y,&ireg,&z];
}


func replot_plf(p1,p2,p3,p4,rslt)
/* DOCUMENT replot_plf(prop)
   Same as replot but only for plf graphical elements
   SEE ALSO: replot
 */
{
  if(p1(1)!=5) error,"Bad properties !!";
  plf,*rslt(4),*rslt(2),*rslt(1),legend=p2,hide=p1(2),
    region=p3(1),edges=p3(2),ecolor=get_color(p3(3)),
    ewidth=p4(1);
}

func reshape_plv(prop)
{
  local p1,p2,p3,p4,p5;
  local x,y,ireg,vx,vy;
  decomp_prop,prop,p1,p2,p3,p4,p5;
  if(p1(1)!=6) error,"Bad properties !!";
  adx =p5(3);reshape,x,adx,double,[2,p5(1),p5(2)];
  ady =p5(4);reshape,y,ady,double,[2,p5(1),p5(2)];
  adi =p5(5);reshape,ireg,adi,int,[2,p5(1),p5(2)];
  advx=p5(6);reshape,vx,advx,double,[2,p5(1),p5(2)];
  advy=p5(7);reshape,vy,advy,double,[2,p5(1),p5(2)];
  return [&x,&y,&ireg,&vx,&vy];
}

func replot_plv(p1,p2,p3,p4,rslt)
/* DOCUMENT replot_plv(prop)
   Same as replot but only for plv graphical elements
   SEE ALSO: replot
 */
{
  if(p1(1)!=6) error,"Bad properties !!";
  plv,*rslt(5),*rslt(4),*rslt(2),*rslt(1),*rslt(3),hide=p1(2),legend=p2,
    region=p3(1),color=get_color(p3(2)),hollow=p3(3),
    width=p4(1),aspect=p4(2),scale=p4(3);
}

func reshape_plc(prop)
{
  local p1,p2,p3,p4,p5;
  local x,y,ireg,z,tria,levels;
  decomp_prop,prop,p1,p2,p3,p4,p5;
  if(p1(1)!=7) error,"Bad properties !!";
  adx=p5(3);reshape,x,adx,double,[2,p5(1),p5(2)];
  ady=p5(4);reshape,y,ady,double,[2,p5(1),p5(2)];
  adi=p5(5);reshape,ireg,adi,int,[2,p5(1),p5(2)];
  adz=p5(6);reshape,z,adz,double,[2,p5(1),p5(2)];
  adt=p5(7);reshape,tria,adt,short,[2,p5(1),p5(2)];
  adl=p5(9);reshape,levels,adl,double,[1,p5(8)];
  return [&x,&y,&ireg,&z,&tria,&levels];
}


func replot_plc(p1,p2,p3,p4,rslt)
/* DOCUMENT replot_plc(prop)
   Same as replot but only for plc graphical elements
   SEE ALSO: replot
 */
{
  if(p1(1)!=7) error,"Bad properties !!";
  plc,*rslt(4),*rslt(2),*rslt(1),*rslt(3),levs=*rslt(6),legend=p2,hide=p1(2),
    region=p3(1),color=get_color(p3(2)),type=p3(3),
    marks=p3(4),mcolor=p3(5),marker=p3(6),smooth=p3(7),
    width=p4(1),msize=p4(2),mspace=p4(3),mphase=p4(4),
    triangle=*rslt(5);
}

func reshape_pli(prop)
{
  local p1,p2,p3,p4,p5;
  local colors;
  decomp_prop,prop,p1,p2,p3,p4,p5;
  if(p1(1)!=8) error,"Bad properties !!";
  adc=p5(3);reshape,colors,adc,char,[2,p5(1),p5(2)];
  return [&colors];
}

func replot_pli(p1,p2,p3,p4,rslt)
/* DOCUMENT replot_pli(prop)
   Same as replot but only for pli graphical elements
   SEE ALSO: replot
 */
{
  if(p1(1)!=8) error,"Bad properties !!";
  pli,*rslt(1),p4(1),p4(2),p4(3),p4(4),legend=p2,hide=p1(2);
}

func reshape_plfp(prop)
{
  local p1,p2,p3,p4,p5;
  local pn,x,y,z;
  decomp_prop,prop,p1,p2,p3,p4,p5;
  if(p1(1)!=9) error,"Bad properties !!";
  adpn=p5(5);reshape,pn,adpn,long,[1,p5(1)];
  adx =p5(3);reshape,x,adx,double,[1,sum(pn)];
  ady =p5(2);reshape,y,ady,double,[1,sum(pn)];
  adz =p5(4);
  if(p5(1)&&p5(4))
    if(p3(3)) //RGB mode
      reshape,z,adz,char,[2,3,p5(1)];
    else
      reshape,z,adz,char,[1,p5(1)];
  else
    z=[];
  
  if(is_void(z)) return [&x,&y,&pn];
  return [&x,&y,&z,&pn];
}

func replot_plfp(p1,p2,p3,p4,rslt)
/* DOCUMENT replot_plfp(prop)
   Same as replot but only for plfp graphical elements
   SEE ALSO: replot
 */
{
  if(p1(1)!=9) error,"Bad properties !!";
  if(numberof(rslt)==3)
    plfp,,*rslt(1),*rslt(2),*rslt(3),hide=p1(2),legend=p2,
      edges=p3(1),ecolor=get_color(p3(2)),ewidth=p4(1);
  else
    plfp,*rslt(3),*rslt(1),*rslt(2),*rslt(4),hide=p1(2),legend=p2,
      edges=p3(1),ecolor=get_color(p3(2)),ewidth=p4(1);
}

func decomp_prop(prop,&prop1,&prop2,&prop3,&prop4,&prop5)
/* DOCUMENT  decomp_prop(prop,&p1,&p2,&p3,&p4,&p5)
   Put in propi the array *prop(i);
 */
{
  prop1=*prop(1);
  prop2=*prop(2);
  prop3=*prop(3);
  prop4=*prop(4);
  prop5=*prop(5);
}

func get_nb_sys(win,dims=)
/* DOCUMENT get_nb_sys(win)
   Return the numberof og system in the window 'win'. If win is ommited, return
   the numberof of system in the current window.
   This routine does not change the selected window.
   SEE ALSO:
 */
{
  local a,b,c,d;
  if(is_void(dims)) dims=0;
  wbck = get_selected_system();
  window,win;  get_style,a,b,c,d;
  set_selected_system,wbck;

  if(dims) return dimsof(b);
  return numberof(b);
}

func get_color(color)
/* DOCUMENT get_color(color)
   Check if color is a rgb encoded color. If so return the array
   [red,green,blue], else just return color.
 */
{
  if(!(color&0xF000000)) return color;
  red  =(color&0x00000FF);
  green=(color&0x000FF00)>>8;
  blue =(color&0x0FF0000)>>16;
  return char([red,green,blue]);
}

func get_selected_system(void)
/* DOCUMENT bkp=get_selected_system();

   Return the current selected system and window
   
   SEE ALSO: set_selected_system
 */
{
  cur_win=current_window();
  cur_sys=(cur_win>0)?plsys():-1;
  return [cur_win,cur_sys];
}

func set_selected_system(saved_sys)
/* DOCUMENT set_selected_system(saved_sys)

   Set the window number to SAVED_SYS(1) and the system number
   to SAVED_SYS(2) and return the window and system number before
   the modification.
   Use it with get_selected_system. The usual way of using these
   two functions is:

   bck = get_selected_system
   // you can change window and system with window,#
   // and plsys,#
   // And to go back to the window and the system
   // before all these modifications:
   set_selected_system,bck
   
   
   SEE ALSO: get_selected_system
 */
{
  tmp=get_selected_system();
  if(saved_sys(1)>=0) {
    window,saved_sys(1);
    if(saved_sys(2)>=0) plsys,saved_sys(2);
  }
  return tmp;
}