<![CDATA[ npoles=3; poles[0]= [ 0,0]; poles[1]= [ 0,0]; poles[2]= [-1,0]; nzeros=1; zeros[0]= [-1/3,0]; var ds=.02; var dw=.02; function Blob(x,c){ Colour(c); BoxFill(x[0]-ds/2,x[1]+dw/2,x[0]+ds/2,x[1]-dw/2); } function Blip(x,c){ Colour(c); BoxFill(x[0]-ds/4,x[1]+dw/4,x[0]+ds/4,x[1]-dw/4); } function Showroots(){ for(i=0;i<npoles;i++){ Blob(poles[i],"black"); } for(i=0;i<nzeros;i++){ Blob(zeros[i],"black"); Blip(zeros[i],"white"); } } ScaleWindow(-1.6,-1,1.6,1); for(s[1]=-.98;s[1]<1;s[1]+=dw){ for(s[0]=-1.58;s[0]<1.6;s[0]+=ds){ getgain(s); if(gain[1]>0){ Blob(s,"red"); } if(gain[1]<0){ Blob(s,"yellow"); } if(gain[0]>0){ Blip(s,"white"); } } } DrawAxes(-1.5,-1,1.5,1); Showroots(); Colour("black"); Label('Root locus - gain map',.5,.5); ]]>