////// Figures /////

Ketinit();
Usegraphics("pict2e");
Addax(0);

//Setscaling(0.2);
fun="3*x^4-8*x^3+6*x^2+1/2";
f(x):=parse(Assign(fun,["x",x]));
Plotdata("1",fun,"x=[-2,2]");
Listplot("x",[[XMIN,0],[XMAX,0]]);
Listplot("y",[[0,-0.2],[0,YMAX]]);
Expr([[XMAX,0],"e1","x",[0,YMAX],"n1","y"]);
Letter([[0,0],"s1w1","O"]);
Htickmark([1,"1"]);
Vtickmark([1/2,"sw","\frac{1}{2}"]);
tmp=Totexform("y="+fun);
Expr([1,1],"e",tmp);


Ch=[1,2];
//Ch=[1,2];
if(contains(Ch,1),
 cmdL=[
  "f[x_]:="+fun,[],
  "df=D",["f[x]","x"],
  "zero=Solve",["df==0","x"],
  "sL={}",[],
  "For[i=1,i<=Length[zero],i++,",[],
  "  xi=x/.zero[[i]];",[],
  "  sL=Append[sL,{xi,f[xi]}]",[],
  "]",[],
  "sL=Union[sL]",[],
  "sL=Sort[sL,#1[[1]]<#2[[1]]&]",[],
  "df::sL",[]
 ];
 CalcbyW("dt",cmdL);
 df(x):=parse(Assign(dt_1,["x",x]));
 pL=TocindyW(dt_2);
 println(pL);
 pLv=apply(pL,parse(#));
 println(pLv);
);

if(contains(Ch,2),
 xL=apply(pLv,#_1);
 mdL=apply(1..(length(xL)-1),(xL_#+xL_(#+1))/2);
 mdL=prepend(xL_1-1,mdL);
 mdL=append(mdL,xL_(-1)+1);
 sgL=apply(mdL,if(df(#)>0,"+","-"));
 arL=apply(sgL,if(#=="+","\NEarrow","\SEarrow"));
 xLst=[];
 forall(1..(length(xL)+length(mdL)),
   if(mod(#,2)==1,tmp=10,tmp=8);
   xLst=append(xLst,tmp);
 );
 xLst=prepend(8,xLst);
 yLst=[8,8,8];
 rmvL=[];
 Tabledatalight("",xLst,yLst,rmvL,["Move=[-2,-3]"]);
 Putcolexpr(1,"c",["x","y'","y"]);
 forall(1..(length(mdL)),
   Putcolexpr(2*#,"c",["\cdots",sgL_#,arL_#]);
 );
 forall(1..(length(xL)),
   tmp=Fracform(f(xL_#),10,4);
   tmp=Totexform(tmp_1);
   Putcolexpr(2*#+1,"c",[xL_#,0,tmp]);
 );
);

Windispg();