Task
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
[https://photos.app.goo.gl/58heQVm8UJYf8Ra29 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
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 ""
Go
Infix
{{trans|Nim}}
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("")
}
RPN
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("")
}
Nim
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
RPN
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
Infix
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
Perl
Infix
{{trans|Perl 6}}
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);
{{out}}
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
{{trans|Nim}}
```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;
```
{{out}}
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
```
## Phix
```Phix
-- node contents:
enum KIND, -- '+', '*', or 'r'
RESISTANCE, VOLTAGE,
A, B -- nested nodes or NULL
function resistance(sequence node)
switch node[KIND] do
case '+': return resistance(node[A]) + resistance(node[B])
case '*': return 1 / (1/resistance(node[A]) + 1/resistance(node[B]))
case 'r': return node[RESISTANCE]
default: ?9/0 -- unknown node kind
end switch
end function
function setVoltage(sequence node, atom voltage)
switch node[KIND] do
case '+':
atom ra := resistance(node[A]),
rb := resistance(node[B])
node[A] = setVoltage(node[A], ra / (ra + rb) * voltage)
node[B] = setVoltage(node[B], rb / (ra + rb) * voltage)
case '*':
node[A] = setVoltage(node[A],voltage)
node[B] = setVoltage(node[B],voltage)
end switch
node[VOLTAGE] = voltage
return node
end function
function current(sequence node)
return node[VOLTAGE] / resistance(node)
end function
function effect(sequence node)
return current(node) * node[VOLTAGE]
end function
procedure report(sequence node, string level="")
printf(1,"%8.3f %8.3f %8.3f %8.3f %s%c\n", {resistance(node), node[VOLTAGE], current(node), effect(node), level, node[KIND]})
if node[A]!=NULL then
report(node[A],level & "| ")
end if
if node[B]!=NULL then
report(node[B],level & "| ")
end if
end procedure
function push(sequence stack, string tok)
switch tok do
case "+","*": sequence b = stack[$],
a = stack[$-1]
stack = stack[1..$-1]
stack[$] = {tok[1], 0, 0, a, b}
default: integer {{r}} = scanf(tok,"%d")
stack = append(stack,{'r', r, 0, NULL, NULL})
end switch
return stack
end function
```
### RPN
```Phix
function rpn(string s)
sequence stack = {},
tokens = split(s)
for i=1 to length(tokens) do
stack = push(stack,tokens[i])
end for
return stack[$]
end function
sequence node = rpn("10 2 + 6 * 8 + 6 * 4 + 8 * 4 + 8 * 6 +")
node = setVoltage(node,18)
printf(1," Ohm Volt Ampere Watt Network tree\n")
report(node,"")
```
{{out}}
```txt
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
```
### infix
slightly trickier
```Phix
constant ops = {"+","*"}
function infix(string s)
string lastnum = ""
sequence tokens = {}
for i=1 to length(s) do
integer ch = s[i]
if ch>='0' and ch<='9' then
lastnum &= ch
else
if length(lastnum) then
tokens = append(tokens,lastnum)
lastnum = ""
end if
tokens = append(tokens,ch&"")
end if
end for
if length(lastnum) then
tokens = append(tokens,lastnum)
end if
sequence stack = {}, result = {}
for i=1 to length(tokens) do
string token = tokens[i], op
switch token do
case "(": stack = append(stack,token)
case ")": while true do
op = stack[$]
stack = stack[1..$-1]
if op == "(" then break end if
result = push(result,op)
end while
else:
integer tp = find(token,ops)
if tp then
while length(stack) do
op = stack[$]
integer sp = find(op,ops)
if not sp or tp>=sp then exit end if
stack = stack[1..$-1]
result = push(result,op)
end while
stack = append(stack,token)
else
result = push(result,token)
end if
end switch
end for
for i=length(stack) to 1 by -1 do
result = push(result,stack[i])
end for
return result[1]
end function
sequence node = infix("((((10+2)*6+8)*6+4)*8+4)*8+6")
```
then as per last 3 lines of RPN, same output.
## Python
### RPN
```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()
```
### Infix
```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()
```
## zkl
```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) }
}
```
### Infix
```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();
```
{{out}}
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
```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();
```
{{out}}
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
```