continue with new parser, steps now seem way more clear

This commit is contained in:
NunoSempere 2024-06-09 13:18:09 +02:00
parent f5e7148148
commit de72432c53

76
f2.go
View File

@ -2,13 +2,17 @@ package main
import (
"bufio"
"errors"
"fmt"
// "math"
"os"
// "strconv"
"strings"
)
const NORMAL90CONFIDENCE = 1.6448536269514727
// Actually, I should look up how do do a) enums in go, b) union types
type Lognormal struct {
low float64
@ -21,21 +25,83 @@ type Dist struct {
Samples []float64
}
// Parse line into Distribution,
func parseLine(line string) (string, Dist, error) {
words := strings.Split(strings.TrimSpace(line), " ")
op = ""
var dist Dist
switch {
case len(words) == 2 && words[0] == "*":
fmt.Printf("Hello world")
switch words[0] {
case "*":
op = "*"
case "/":
op = "/"
case "+":
return "", Dist{}, error.New("+ operation not implemented yet")
case "-":
return "", Dist{}, error.New("- operation not implemented yet")
default:
return "", Dist{}, error.New("operation not recognized")
}
return "Lognormal", Dist{}, nil
switch len(words) {
case 1:
return "", Dist{}, error.New("Can't operate on nothing")
case 2:
single_float, err1 := strconv.ParseFloat(words[1], 64)
if err1 != nil {
fmt.Println("Trying to operate on a scalar, but scalar is not a float")
fmt.Println(error_msg_cont)
continue EventForLoop
}
new_low = single_float
new_high = single_float
}
}
// Join distributions
// Multiply lognormals
func logBoundsToLogParams(low float64, high float64) (float64, float64) {
loglow := math.Log(low)
loghigh := math.Log(high)
logmean := (loghigh + loglow) / 2.0
logstd := (loghigh - loglow) / (2.0 * NORMAL90CONFIDENCE)
return logmean, logstd
}
func logParamsToLogBounds(logmean float64, logstd float64) (float64, float64) {
h := logstd * NORMAL90CONFIDENCE
loglow := logmean - h
loghigh := logmean + h
return math.Exp(loglow), math.Exp(loghigh)
}
func multiplyLogParams(logmean1 float64, logstd1 float64, logmean2 float64, logstd2 float64) (float64, float64) {
return logmean1 + logmean2, math.Sqrt(logstd1*logstd1 + logstd2*logstd2)
}
func multiplyLogBounds(old_low, old_high, new_low, new_high float64) (float64, float64) {
logmean_old, logstd_old := logBoundsToLogParams(old_low, old_high)
logmean_new, logstd_new := logBoundsToLogParams(new_low, new_high)
logmean_product, logstd_product := multiplyLogParams(logmean_old, logstd_old, logmean_new, logstd_new)
return logParamsToLogBounds(logmean_product, logstd_product)
}
func joinDists(old_dist Dist, new_dist Dist, op string) (Dist, error) {
return old_dist, nil
switch {
case old_dist.Type == "Lognormal" && new_dist.Type == "Lognormal" && op == "*":
low, high := multiplyLogBounds(old_dist.Lognormal.low, old_dist.Lognormal.high, new_dist.Lognormal.low, new_dist.Lognormal.high)
return Dist{Type: "Lognormal", Lognormal: Lognormal{low: low, high: high}, Samples: nil}
default:
fmt.Printf("For now, can't do anything besides multiplying lognormals")
}
return old_dist, errors.New("Error blah blah")
}
/* Main event loop */
func main() {
reader := bufio.NewReader(os.Stdin)
old_dist := Dist{Type: "Lognormal", Lognormal: Lognormal{low: 1, high: 1}, Samples: nil} // Could also just be a scalar