1. Cool trick: %%

i understand the meaning of %s_vx%    // to show the value stored in variable s_vx

2. cool trick (int)(vx*10+0.5)/10.+"";

s_vx=(int)(vx*10+0.5)/10.+"";  // to show s_vx as a number say 2.3 instead of 2.3000001

3. my attempt to show 2.3 = vx

constraints page:
s_vx =(int)(vx*100.+0.5)/100.+"=vx" ; // to make display 2.30=vx instead of 2.3000000001

property text

result is still ok  it shows    2.3 =vx

[b]can show example codes to show vx= 2.3 ??[/b]

i read your post, i can't understand this part clearly to implement it the way i want  :(

the function is fantastic !! i corrected the typo errors :)

cut and paste in custom page:

double dv;
public String double2String(double v,double divider){
else if(v<0)dv=-0.5;
else dv=0;
return (int)(v*divider+dv)/divider+"";

cut and paste in constraint page: