Hi
I've been learning nim and playing around with decimal from :
<https://github.com/status-im/nim-decimal>
I'm written some sample code below to calulate a finance thing called weighted
average cost of capital.
In the example below I wanted to round decimal to 0.733 and then convert that
to 7.3%. I did try and convert to a float but had no joy there. It seems once
with a Decimal we're stuck with it.
Questions I have :
1. Is this the correct way to use Decimal and Round values i.e. using
quantize and reduce. I was hoping there would be a round(7.333333,3)
2. Also, I tried using a func for this but compiler complained it wasn't pure
- any ideas why that isn't pure? Can I make it pure?
3. It seems like a lot of typing to write DecimalType and newDecimal - is it
possible in NIM to reduce typing with Dec / newDec
4. I found it bit weird to pass in newDecimal("0.05") i.e. why do I have to
pass a string in for this value? I tried with newDecimal(0.05) but got errors.
I wrote this code mostly by looking at the tests in repo.
Market value of equity (e): 1000000 Market value of debt (d): 2000000 Cost of
equity (rE): 0.15 Cost of debt (rD): 0.05 Tax rate (t): 0.3
proc wacc(e: DecimalType, d: DecimalType, rE: DecimalType, rD: DecimalType,
t:DecimalType ): DecimalType =
let v = e + d
let eV = e / v
let dV = d / v
let adjRD = rD * (1 - t)
return eV * rE + dV * adjRD
let e = newDecimal(1000000)
let d = newDecimal(2000000)
let rE = newDecimal("0.15")
let rD = newDecimal("0.05")
let t = newDecimal("0.3")
let w = wacc(e, d, rE, rD, t)
let y = quantize(w,newDecimal("1e-3"))
echo reduce(y * 100),"%"
Run
Thanks in advance
Nelly
