Resistance calculator: Difference between revisions

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

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>

var node = rpn 18.0,"10 2 + 6 * 8 + 6 * 4 + 8 * 4 + 8 * 6 +"

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()

node = infix 18.0,"((((10+2)*6+8)*6+4)*8+4)*8+6"