Resistance calculator

Resistance calculator is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.

Introduction

• Calculate the resistance of a network of resistors.
• The resistors can be connected in series or parallel.
• Use infix or RPN to state the network.
• Calculate resistance, voltage, current and power for every resistor and operation.

Background

• Serial Resistors: the sum of the resistors gives the equivalent resistor
• Parallel Resistors: the inverse of the sum of the inverse of the resistors
• The voltage drops over the resistors
• Current = Resistance / Voltage
• Power = Current * Voltage

Input

Resistance Calculator

• Infix: ((((10 + 2) * 6 + 8) * 6 + 4) * 8 + 4) * 8 + 6
• RPN: 10 2 + 6 * 8 + 6 * 4 + 8 * 4 + 8 * 6 +
• Voltage = 18.0 V

Output

• 10.000 ohms in the upper left corner is the equivalent resistance.
• The first operation is 10 + 2 = 12 which can be found in the three middle rows.

    Ohm     Volt   Ampere     Watt  Network tree
 10.000   18.000    1.800   32.400  +
  4.000    7.200    1.800   12.960  | *
  8.000    7.200    0.900    6.480  | | +
  4.000    3.600    0.900    3.240  | | | *
  8.000    3.600    0.450    1.620  | | | | +
  4.000    1.800    0.450    0.810  | | | | | *
 12.000    1.800    0.150    0.270  | | | | | | +
  4.000    0.600    0.150    0.090  | | | | | | | *
 12.000    0.600    0.050    0.030  | | | | | | | | +
 10.000    0.500    0.050    0.025  | | | | | | | | | r
  2.000    0.100    0.050    0.005  | | | | | | | | | r
  6.000    0.600    0.100    0.060  | | | | | | | | r
  8.000    1.200    0.150    0.180  | | | | | | | r
  6.000    1.800    0.300    0.540  | | | | | | r
  4.000    1.800    0.450    0.810  | | | | | r
  8.000    3.600    0.450    1.620  | | | | r
  4.000    3.600    0.900    3.240  | | | r
  8.000    7.200    0.900    6.480  | | r
  6.000   10.800    1.800   19.440  | r

CoffeeScript

RPN

<lang coffeescript>nd = (num) -> num.toFixed(3).padStart 8

class Resistor constructor : (@resistance,@a=null,@b=null,@symbol='r') -> res : -> @resistance setVoltage : (@voltage) -> current : -> @voltage / @res() effect : -> @current() * @voltage report : (level) -> print "#{nd @res()} #{nd @voltage} #{nd @current()} #{nd @effect()} #{level}#{@symbol}" if @a then @a.report level + "| " if @b then @b.report level + "| "

class Serial extends Resistor constructor : (a,b) -> super 0,a,b,'+' res : -> @a.res() + @b.res() setVoltage : (@voltage) -> ra = @a.res() rb = @b.res() @a.setVoltage ra/(ra+rb) * @voltage @b.setVoltage rb/(ra+rb) * @voltage

class Parallel extends Resistor constructor : (a,b) -> super 0,a,b,'*' res : -> 1 / (1 / @a.res() + 1 / @b.res()) setVoltage : (@voltage) -> @a.setVoltage @voltage @b.setVoltage @voltage

build = (s) -> stack = [] for word in s.split ' ' if word == '+' then stack.push new Serial stack.pop(), stack.pop() else if word == '*' then stack.push new Parallel stack.pop(), stack.pop() else stack.push new Resistor parseFloat word stack.pop()

node = build "10 2 + 6 * 8 + 6 * 4 + 8 * 4 + 8 * 6 +" node.setVoltage 18.0 print " Ohm Volt Ampere Watt Network tree" node.report ""</lang>

Go

Infix

Translation of: Nim

<lang go>package main

import "fmt"

type Resistor struct {

   symbol              rune
   resistance, voltage float64
   a, b                *Resistor

}

func (r *Resistor) res() float64 {

   switch r.symbol {
   case '+':
       return r.a.res() + r.b.res()
   case '*':
       return 1 / (1/r.a.res() + 1/r.b.res())
   default:
       return r.resistance
   }

}

func (r *Resistor) setVoltage(voltage float64) {

   switch r.symbol {
   case '+':
       ra := r.a.res()
       rb := r.b.res()
       r.a.setVoltage(ra / (ra + rb) * voltage)
       r.b.setVoltage(rb / (ra + rb) * voltage)
   case '*':
       r.a.setVoltage(voltage)
       r.b.setVoltage(voltage)
   }
   r.voltage = voltage

}

func (r *Resistor) current() float64 {

   return r.voltage / r.res()

}

func (r *Resistor) effect() float64 {

   return r.current() * r.voltage

}

func (r *Resistor) report(level string) {

   fmt.Printf("%8.3f %8.3f %8.3f %8.3f  %s%c\n", r.res(), r.voltage, r.current(), r.effect(), level, r.symbol)
   if r.a != nil {
       r.a.report(level + "| ")
   }
   if r.b != nil {
       r.b.report(level + "| ")
   }

}

func (r *Resistor) add(other *Resistor) *Resistor {

   return &Resistor{'+', 0, 0, r, other}

}

func (r *Resistor) mul(other *Resistor) *Resistor {

   return &Resistor{'*', 0, 0, r, other}

}

func main() {

   var r [10]*Resistor
   resistances := []float64{6, 8, 4, 8, 4, 6, 8, 10, 6, 2}
   for i := 0; i < 10; i++ {
       r[i] = &Resistor{'r', resistances[i], 0, nil, nil}
   }
   node := r[7].add(r[9]).mul(r[8]).add(r[6]).mul(r[5]).add(r[4]).mul(r[3]).add(r[2]).mul(r[1]).add(r[0])
   node.setVoltage(18)
   fmt.Println("     Ohm     Volt   Ampere     Watt  Network tree")
   node.report("")

}</lang>

RPN

<lang go>package main

import (

   "fmt"
   "strconv"
   "strings"

)

type Stack []*Resistor

func (s *Stack) push(r *Resistor) {

   *s = append(*s, r)

}

func (s *Stack) pop() *Resistor {

   le := len(*s)
   if le == 0 {
       panic("Attempt to pop from an empty stack")
   }
   le--
   r := (*s)[le]
   *s = (*s)[:le]
   return r

}

type Resistor struct {

   symbol              rune
   resistance, voltage float64
   a, b                *Resistor

}

func (r *Resistor) res() float64 {

   switch r.symbol {
   case '+':
       return r.a.res() + r.b.res()
   case '*':
       return 1 / (1/r.a.res() + 1/r.b.res())
   default:
       return r.resistance
   }

}

func (r *Resistor) setVoltage(voltage float64) {

   switch r.symbol {
   case '+':
       ra := r.a.res()
       rb := r.b.res()
       r.a.setVoltage(ra / (ra + rb) * voltage)
       r.b.setVoltage(rb / (ra + rb) * voltage)
   case '*':
       r.a.setVoltage(voltage)
       r.b.setVoltage(voltage)
   }
   r.voltage = voltage

}

func (r *Resistor) current() float64 {

   return r.voltage / r.res()

}

func (r *Resistor) effect() float64 {

   return r.current() * r.voltage

}

func (r *Resistor) report(level string) {

   fmt.Printf("%8.3f %8.3f %8.3f %8.3f  %s%c\n", r.res(), r.voltage, r.current(), r.effect(), level, r.symbol)
   if r.a != nil {
       r.a.report(level + "| ")
   }
   if r.b != nil {
       r.b.report(level + "| ")
   }

}

func build(rpn string) *Resistor {

   st := new(Stack)
   for _, token := range strings.Fields(rpn) {
       switch token {
       case "+":
           b, a := st.pop(), st.pop()
           st.push(&Resistor{'+', 0, 0, a, b})
       case "*":
           b, a := st.pop(), st.pop()
           st.push(&Resistor{'*', 0, 0, a, b})
       default:
           r, _ := strconv.ParseFloat(token, 64)
           st.push(&Resistor{'r', r, 0, nil, nil})
       }
   }
   return st.pop()

}

func main() {

   node := build("10 2 + 6 * 8 + 6 * 4 + 8 * 4 + 8 * 6 +")
   node.setVoltage(18)
   fmt.Println("     Ohm     Volt   Ampere     Watt  Network tree")
   node.report("")

}</lang>

Nim

<lang python>import tables,strutils,sequtils,sugar,strformat

type Node = ref object kind : char # + = serial * = parallel r = resistor resistance : float voltage : float a : Node b : Node

proc res(node : Node) : float = if node.kind == '+' : return node.a.res + node.b.res if node.kind == '*' : return 1/(1/node.a.res + 1/node.b.res) node.resistance

proc current(node : Node) : float = return node.voltage / node.res proc effect (node : Node) : float = return node.current * node.voltage

proc report(node : Node, level : string = "") = echo fmt"{node.res:8.3f} {node.voltage:8.3f} {node.current:8.3f} {node.effect:8.3f} {level}{node.kind}" if node.kind in "+*": node.a.report level & "| " node.b.report level & "| "

proc setVoltage(node : Node, voltage : float) = node.voltage = voltage if node.kind == '+': let ra = node.a.res let rb = node.b.res node.a.setVoltage ra/(ra+rb) * voltage node.b.setVoltage rb/(ra+rb) * voltage if node.kind == '*': node.a.setVoltage voltage node.b.setVoltage voltage

proc build(tokens : seq[string]) : Node = var stack : seq[Node] for token in tokens: if token == "+": stack.add Node(kind : '+', a : stack.pop, b : stack.pop) elif token == "*": stack.add Node(kind : '*', a : stack.pop, b : stack.pop) else: stack.add Node(kind : 'r', resistance : parseFloat(token)) stack.pop

proc calculate(voltage:float, tokens:seq[string]): Node = echo "" echo " Ohm Volt Ampere Watt Network tree" let node = build tokens node.setVoltage voltage node.report node</lang>

RPN

<lang python>proc rpn(voltage:float, s:string): Node = calculate(voltage, s.split ' ') var node = rpn 18.0,"10 2 + 6 * 8 + 6 * 4 + 8 * 4 + 8 * 6 +" assert 10 == node.res assert 18 == node.voltage assert 1.8 == node.current() assert 32.4 == node.effect() assert '+' == node.kind</lang>

Infix

<lang python>proc parse(s: string): seq[string] = var tmp = "" for ch in s: if ch == ' ': if tmp!="": result.add tmp tmp = "" continue if ch in "+*()": if tmp!="": result.add tmp tmp="" result.add fmt"{ch}" else: tmp &= ch if tmp!="": result.add tmp

proc shuntRPN(s:string): seq[string] = let ops = "+*" var tokens = parse s var stack: seq[string] var op: string

for token in tokens: case token of "(": stack.add token of ")": while stack.len > 0: op = stack.pop() if op == "(": break result.add op else: if token in ops: while stack.len > 0: op = stack[^1] if not (op in ops): break if ops.find(token) >= ops.find(op): break discard stack.pop() result.add op stack.add token else: result.add token

while stack.len > 0: result.add stack.pop()

proc infix(voltage:float, s:string): Node = calculate(voltage, shuntRPN s) node = infix 18.0,"((((10+2)*6+8)*6+4)*8+4)*8+6" assert 10 == node.res assert 18 == node.voltage assert 1.8 == node.current() assert 32.4 == node.effect() assert '+' == node.kind</lang>

Perl

Infix

Translation of: Perl 6

<lang perl>use strict; use warnings; use feature <say state>;

{ package Resistor;

sub new {

   my ($class, $args) = @_;
   my $self = {
       symbol     => $args->{symbol},
       voltage    => $args->{voltage},
       resistance => $args->{resistance},
       a          => $args->{a},
       b          => $args->{b},
   };
   return bless $self, $class;

}

sub res {

   my $self = shift;
   if    ($self->{symbol} eq '+') { return res($self->{a}) + res($self->{b}) }
   elsif ($self->{symbol} eq '*') { return 1 / (1/res($self->{a}) + 1/res($self->{b})) }
   else  { return $self->{resistance} }

}

sub set_voltage {

   my($self,$voltage) = @_;
   if ($self->{symbol} eq '+') {
       my $ra = res($self->{a});
       my $rb = res($self->{b});
       set_voltage($self->{a}, $ra / ($ra+$rb) * $voltage );
       set_voltage($self->{b}, $rb / ($ra+$rb) * $voltage );
   } elsif ($self->{symbol} eq '*') {
       set_voltage($self->{a}, $voltage );
       set_voltage($self->{b}, $voltage );
   }
   $self->{voltage} = $voltage;

}

sub current { my $self = shift; return $self->{voltage} / res($self) } sub effect { my $self = shift; return $self->{voltage} * current($self) }

use overload '+' => \&serial,

            '*' => \∥

sub serial { my($a,$b) = @_; Resistor->new( {symbol => '+', a => $a, b => $b} ) } sub parallel { my($a,$b) = @_; Resistor->new( {symbol => '*', a => $a, b => $b} ) }

sub report {

   my($self,$level)  = @_;
   state @results;
   push @results, '      Ohm     Volt   Ampere     Watt   Network tree' and $level = 1 unless $level;
   my $pad = ('| ') x $level;
   my $f = sprintf '%9.3f' x 4, res($self), $self->{voltage}, current($self), effect($self);
   say "$f $pad" . $self->{symbol};
   report($self->{a}, $level+1) if defined $self->{a};
   report($self->{b}, $level+1) if defined $self->{b};
   join "\n", @results;

}

}

package main;

my ($R1, $R2, $R3, $R4, $R5, $R6, $R7, $R8, $R9, $R10) =

   map { Resistor->new( {symbol => 'r', resistance => $_} ) } <6 8 4 8 4 6 8 10 6 2>;

my $node = (((($R8 + $R10) * $R9 + $R7) * $R6 + $R5)

                          * $R4 + $R3) * $R2 + $R1;

Resistor::set_voltage($node,18); say Resistor::report($node);</lang>

Output:

      Ohm     Volt   Ampere     Watt   Network tree
   10.000   18.000    1.800   32.400 | +
    4.000    7.200    1.800   12.960 | | *
    8.000    7.200    0.900    6.480 | | | +
    4.000    3.600    0.900    3.240 | | | | *
    8.000    3.600    0.450    1.620 | | | | | +
    4.000    1.800    0.450    0.810 | | | | | | *
   12.000    1.800    0.150    0.270 | | | | | | | +
    4.000    0.600    0.150    0.090 | | | | | | | | *
   12.000    0.600    0.050    0.030 | | | | | | | | | +
   10.000    0.500    0.050    0.025 | | | | | | | | | | r
    2.000    0.100    0.050    0.005 | | | | | | | | | | r
    6.000    0.600    0.100    0.060 | | | | | | | | | r
    8.000    1.200    0.150    0.180 | | | | | | | | r
    6.000    1.800    0.300    0.540 | | | | | | | r
    4.000    1.800    0.450    0.810 | | | | | | r
    8.000    3.600    0.450    1.620 | | | | | r
    4.000    3.600    0.900    3.240 | | | | r
    8.000    7.200    0.900    6.480 | | | r
    6.000   10.800    1.800   19.440 | | r

Perl 6

Infix

Translation of: Nim

<lang perl6>class Resistor {

   has Str        $.symbol;
   has Numeric  ( $.voltage, $.resistance );
   has Resistor ( $.a, $.b );

   method res ( ) {
       given $.symbol {
           when '+' { return $.a.res + $.b.res }
           when '*' { return 1 / (1 / $.a.res  +  1 / $.b.res) }
           default  { return $.resistance }
       }
   }

   method set-voltage ( Numeric $voltage ) {
       given $.symbol {
           when '+' {
               my $ra = $.a.res;
               my $rb = $.b.res;
               $.a.set-voltage( $ra / ($ra+$rb) * $voltage );
               $.b.set-voltage( $rb / ($ra+$rb) * $voltage );
           }
           when '*' {
               $.a.set-voltage( $voltage );
               $.b.set-voltage( $voltage );
           }
       }
       $!voltage = $voltage;
   }
   method current ( ) { return $.voltage / self.res     }
   method effect  ( ) { return $.voltage * self.current }

   method report ( Int $level = 1 ) {
       my $pad = '| ' x $level;
       my $f = ( self.res, $.voltage, self.current, self.effect ).fmt('%8.3f');
       say "$f $pad$.symbol";
       $.a.report( $level+1 ) if $.a;
       $.b.report( $level+1 ) if $.b;
   }

} multi sub infix:<+> (Resistor $a, Resistor $b) { $a.new( symbol => '+', :$a, :$b ) } multi sub infix:<*> (Resistor $a, Resistor $b) { $a.new( symbol => '*', :$a, :$b ) }

my Resistor ($R1, $R2, $R3, $R4, $R5, $R6, $R7, $R8, $R9, $R10) =

   map { Resistor.new: symbol => 'r', resistance => $_ },
   6, 8, 4, 8, 4, 6, 8, 10, 6, 2;

my $node = (((($R8 + $R10) * $R9 + $R7) * $R6 + $R5)

                          * $R4 + $R3) * $R2 + $R1;

$node.set-voltage(18);

say ' Ohm Volt Ampere Watt Network tree'; $node.report;</lang>

Output:

     Ohm     Volt   Ampere     Watt  Network tree
  10.000   18.000    1.800   32.400 | +
   4.000    7.200    1.800   12.960 | | *
   8.000    7.200    0.900    6.480 | | | +
   4.000    3.600    0.900    3.240 | | | | *
   8.000    3.600    0.450    1.620 | | | | | +
   4.000    1.800    0.450    0.810 | | | | | | *
  12.000    1.800    0.150    0.270 | | | | | | | +
   4.000    0.600    0.150    0.090 | | | | | | | | *
  12.000    0.600    0.050    0.030 | | | | | | | | | +
  10.000    0.500    0.050    0.025 | | | | | | | | | | r
   2.000    0.100    0.050    0.005 | | | | | | | | | | r
   6.000    0.600    0.100    0.060 | | | | | | | | | r
   8.000    1.200    0.150    0.180 | | | | | | | | r
   6.000    1.800    0.300    0.540 | | | | | | | r
   4.000    1.800    0.450    0.810 | | | | | | r
   8.000    3.600    0.450    1.620 | | | | | r
   4.000    3.600    0.900    3.240 | | | | r
   8.000    7.200    0.900    6.480 | | | r
   6.000   10.800    1.800   19.440 | | r

Python

RPN

<lang python>class Resistor : def __init__(self, resistance, a=None, b=None, symbol='r'): self.resistance = resistance self.a = a self.b = b self.symbol = symbol def res(self) : return self.resistance def setVoltage(self, voltage): self.voltage = voltage def current(self) : return self.voltage / self.res() def effect(self) : return self.current() * self.voltage def report(self,level=""): print(f"{self.res():8.3f} {self.voltage:8.3f} {self.current():8.3f} {self.effect():8.3f} {level}{self.symbol}") if self.a: self.a.report(level + "| ") if self.b: self.b.report(level + "| ")

class Serial(Resistor) : def __init__(self, a, b) : super().__init__(0, b, a, '+') def res(self) : return self.a.res() + self.b.res() def setVoltage(self, voltage) : ra = self.a.res() rb = self.b.res() self.a.setVoltage(ra/(ra+rb) * voltage) self.b.setVoltage(rb/(ra+rb) * voltage) self.voltage = voltage

class Parallel(Resistor) : def __init__(self,a,b) : super().__init__(0, b, a, '*') def res(self) : return 1 / (1 / self.a.res() + 1 / self.b.res()) def setVoltage(self, voltage) : self.a.setVoltage(voltage) self.b.setVoltage(voltage) self.voltage = voltage

def build(s) : stack = [] for word in s.split(' '): if word == "+": stack.append(Serial(stack.pop(), stack.pop())) elif word == "*": stack.append(Parallel(stack.pop(), stack.pop())) else: stack.append(Resistor(float(word))) return stack.pop()

node = build("10 2 + 6 * 8 + 6 * 4 + 8 * 4 + 8 * 6 +") print(" Ohm Volt Ampere Watt Network tree") node.setVoltage(18.0) node.report()</lang>

Infix

<lang python>class Resistor : def __init__(self, resistance, a=None, b=None, symbol='r') : self.resistance = resistance self.a = a self.b = b self.symbol = symbol def res(self) : return self.resistance def setVoltage(self, voltage) : self.voltage = voltage def current(self) : return self.voltage / self.res() def effect(self) : return self.current() * self.voltage def report(self,level="") : print(f"{self.res():8.3f} {self.voltage:8.3f} {self.current():8.3f} {self.effect():8.3f} {level}{self.symbol}") if self.a: self.a.report(level + "| ") if self.b: self.b.report(level + "| ") def __add__(self,other) : return Serial(self,other) def __mul__(self,other) : return Parallel(self,other)

class Serial(Resistor) : def __init__(self, a, b) : super().__init__(0, a, b, '+') def res(self) : return self.a.res() + self.b.res() def setVoltage(self, voltage) : ra = self.a.res() rb = self.b.res() self.a.setVoltage(ra/(ra+rb) * voltage) self.b.setVoltage(rb/(ra+rb) * voltage) self.voltage = voltage

class Parallel(Resistor) : def __init__(self,a,b) : super().__init__(0, a, b, '*') def res(self) : return 1 / (1 / self.a.res() + 1 / self.b.res()) def setVoltage(self, voltage): self.a.setVoltage(voltage) self.b.setVoltage(voltage) self.voltage = voltage

[R1,R2,R3,R4,R5,R6,R7,R8,R9,R10] = [Resistor(res) for res in [6,8,4,8,4,6,8,10,6,2]] node = ((((R8+R10) * R9 + R7) * R6 + R5) * R4 + R3) * R2 + R1 node.setVoltage(18) print(" Ohm Volt Ampere Watt Network tree") node.report()</lang>

zkl

<lang zkl>class Resistor{

  fcn init(resistance_,symbol_="r", a_=Void, b_=Void){
     var resistance,a,b,symbol, voltage=Void;
     resistance,symbol,a,b = vm.arglist;
     resistance=resistance.toFloat();  // deal with strings/ints
  }
  fcn res{ 
     if     (symbol=="+") a.res() + b.res();
     else if(symbol=="*") 1.0/(1.0/a.res() + 1.0/b.res());
     else                 resistance
  }
  fcn setVoltage(voltage){ 
     if(symbol=="+"){
        ra,rb := a.res(), b.res();

a.setVoltage(ra/(ra + rb)*voltage); b.setVoltage(rb/(ra + rb)*voltage);

     }
     else if(symbol=="*") T(a,b).apply2("setVoltage",voltage);
     self.voltage = voltage.toFloat();
  }
  fcn current{ voltage/res()     }
  fcn effect { current()*voltage }
  fcn report(level=""){
     println("%8.3f %8.3f %8.3f %8.3f  %s%s".fmt(res(),voltage,current(),effect(),level,symbol));
     T(a,b).apply2("report",level + "| ");  // noop if Void
  }
  fcn __opAdd(other){ Resistor(0,"+",self,other) }
  fcn __opMul(other){ Resistor(0,"*",self,other) }

}</lang>

Infix

<lang zkl>R1,R2,R3,R4,R5,R6,R7,R8,R9,R10 := T(6,8,4,8,4,6,8,10,6,2].apply(Resistor); node:=((((R8 + R10)*R9 + R7)*R6 + R5)*R4 + R3)*R2 + R1; node.setVoltage(18); println(" Ohm Volt Ampere Watt Network tree"); node.report();</lang>

Output:

     Ohm     Volt   Ampere     Watt  Network tree
  10.000   18.000    1.800   32.400  +
   4.000    7.200    1.800   12.960  | *
   8.000    7.200    0.900    6.480  | | +
   4.000    3.600    0.900    3.240  | | | *
   8.000    3.600    0.450    1.620  | | | | +
   4.000    1.800    0.450    0.810  | | | | | *
  12.000    1.800    0.150    0.270  | | | | | | +
   4.000    0.600    0.150    0.090  | | | | | | | *
  12.000    0.600    0.050    0.030  | | | | | | | | +
  10.000    0.500    0.050    0.025  | | | | | | | | | r
   2.000    0.100    0.050    0.005  | | | | | | | | | r
   6.000    0.600    0.100    0.060  | | | | | | | | r
   8.000    1.200    0.150    0.180  | | | | | | | r
   6.000    1.800    0.300    0.540  | | | | | | r
   4.000    1.800    0.450    0.810  | | | | | r
   8.000    3.600    0.450    1.620  | | | | r
   4.000    3.600    0.900    3.240  | | | r
   8.000    7.200    0.900    6.480  | | r
   6.000   10.800    1.800   19.440  | r

RPN

<lang zkl>fcn build(rpnStr){

  stack:=List();
  foreach symbol in (rpnStr.split()){
     if(symbol=="+"){
        a,b:=stack.pop(),stack.pop();

stack.append(Resistor(0,"+",b,a))

     }
     else if(symbol=="*"){
        a,b:=stack.pop(),stack.pop();
     	 stack.append(Resistor(0,"*",b,a))
     }
     else stack.append(Resistor(symbol,"r")); 
  }
  stack.pop()	// unevaluated top of circuit

}

node:=build("10 2 + 6 * 8 + 6 * 4 + 8 * 4 + 8 * 6 +"); node.setVoltage(18); println(" Ohm Volt Ampere Watt Network tree"); node.report();</lang>

Output:

     Ohm     Volt   Ampere     Watt  Network tree
  10.000   18.000    1.800   32.400  +
   4.000    7.200    1.800   12.960  | *
   8.000    7.200    0.900    6.480  | | +
   4.000    3.600    0.900    3.240  | | | *
   8.000    3.600    0.450    1.620  | | | | +
   4.000    1.800    0.450    0.810  | | | | | *
  12.000    1.800    0.150    0.270  | | | | | | +
   4.000    0.600    0.150    0.090  | | | | | | | *
  12.000    0.600    0.050    0.030  | | | | | | | | +
  10.000    0.500    0.050    0.025  | | | | | | | | | r
   2.000    0.100    0.050    0.005  | | | | | | | | | r
   6.000    0.600    0.100    0.060  | | | | | | | | r
   8.000    1.200    0.150    0.180  | | | | | | | r
   6.000    1.800    0.300    0.540  | | | | | | r
   4.000    1.800    0.450    0.810  | | | | | r
   8.000    3.600    0.450    1.620  | | | | r
   4.000    3.600    0.900    3.240  | | | r
   8.000    7.200    0.900    6.480  | | r
   6.000   10.800    1.800   19.440  | r