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Pin width change

Gurup

Hi, 

 I am writing a code to change the pin width cyclically, and be lwo is my code

sel_pin=css()

if(sel_pin ~>objType == "rect" && sel_pin~>children != nil then

p_width=caadr(sel_path~>bBox)-caar(sel_path~>bBox)

cond(
(p_width<0.2   p_width=0.5)
(p_width<=0.2 && p_width<0.6 p_width=0.6)
(p_width>=0.6 && p_width<1 p_width=1)
(p_width>=1 && p_width<2 p_width=2)
(p_width>=2 p_width=.2)
);end cond

pin_width=p_width
crd1=car(sel_pin~>bBox)
crd2=list(car(crd1)+pin_width cadr(crd1)+pin_width)
sel_pin~>bBox=list(crd1 crd2)
sel_pin~>children~>xy=list(car(crd1)+(pin_width/2.0) cadr(crd1)+(pin_width/2.0))
sel_pin~>children~>height=(pin_width/2)

);end if

When I exucte the code for pin width 0.2, then the Cond statement not changing the p_width to 0.6.

Its taking p_width<0.2 is true when pin width is 0.2.

Please correct me if any thing is wrong

Parents
  • Gurup

    And in  different coordinate the p_width is changing .. and in some coordinate its struck one value

  • Andrew Beckett
    in reply to Gurup

    One way to deal with these floating point rounding errors (which have been covered many times in these forums and elsewhere for numerous programming languages - this is not an issue unique to SKILL) is to introduce an error term (epsilon) in the comparisons. In this case I set it to a small number (e.g. one tenth of your probably database unit - often people have a DBU of 1nm, so I set it to 0.1nm). Then make the comparison including this term:

    epsilon=1e-4 ; assuming you have a DBUperUU of 0.001 this would be a tenth of the resolution (could be tighter still)
    cond(
      (p_width<0.2-epsilon p_width=0.5)
      (p_width>=0.2-epsilon && p_width<0.6-epsilon p_width=0.6)
      (p_width>=0.6-epsilon && p_width<1-epsilon p_width=1)
      (p_width>=1-epsilon && p_width<2-epsilon p_width=2)
      (p_width>=2-epsilon p_width=.2)
    );end cond

    By the way, your second branch in the cond statement had (I believe) the comparison the wrong way around (it had <= rather than >=)

    Regards,

    Andrew.

  • Gurup
    in reply to Andrew Beckett

    Thank you very much mbracht and Andrew

Reply
  • Gurup
    in reply to Andrew Beckett

    Thank you very much mbracht and Andrew

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