more feng shui

f.go

@@ -59,7 +59,6 @@ func (ln Lognormal) Samples() []float64 {
 
 func (beta Beta) Samples() []float64 {
 	sampler := func(r sample.Src) float64 { return sample.Sample_beta(beta.a, beta.b, r) }
-	// return sample.Sample_parallel(sampler, N_SAMPLES)
 	return sample.Sample_serially(sampler, N_SAMPLES)
 }
 
@@ -68,7 +67,7 @@ func (fs FilledSamples) Samples() []float64 {
 }
 
 /* Constants */
-const GENERAL_ERR_MSG = "  Operation | Variable assignment | Special\n" +
+const HELP_MSG = "  Operation | Variable assignment | Special\n" +
 	"    Operation:                             operator operand\n" +
 	"          operator:                        (empty) | * | / | + | -\n" +
 	"          operand:                         scalar | lognormal | beta | variable\n" +
@@ -94,131 +93,55 @@ const NORMAL90CONFIDENCE = 1.6448536269514727
 const INIT_DIST Scalar = Scalar(1)
 const N_SAMPLES = 100_000
 
-/* Pretty print for distributions */
+/* Printers */
-// Needs types
 func prettyPrintDist(dist Dist) {
 	switch v := dist.(type) {
 	case Lognormal:
 		fmt.Printf("=> ")
 		pretty.PrettyPrint2Floats(v.low, v.high)
-	case FilledSamples:
+		fmt.Println()
-		tmp_xs := make([]float64, N_SAMPLES)
-		copy(tmp_xs, v.xs)
-		sort.Slice(tmp_xs, func(i, j int) bool {
-			return tmp_xs[i] < tmp_xs[j]
-		})
-		low_int := N_SAMPLES / 20
-		low := tmp_xs[low_int]
-		high_int := N_SAMPLES * 19 / 20
-		high := tmp_xs[high_int]
-		fmt.Printf("=> ")
-		pretty.PrettyPrintFloat(low)
-		fmt.Printf(" ")
-		pretty.PrettyPrintFloat(high)
-		fmt.Printf(" (")
-		pretty.PrettyPrintInt(N_SAMPLES)
-		fmt.Printf(" samples)\n")
 	case Beta:
 		fmt.Printf("=> beta ")
 		pretty.PrettyPrint2Floats(v.a, v.b)
+		fmt.Println()
 	case Scalar:
 		fmt.Printf("=> scalar ")
 		w := float64(v)
 		pretty.PrettyPrintFloat(w)
 		fmt.Println()
+	case FilledSamples:
+		sorted_xs := make([]float64, N_SAMPLES)
+		copy(sorted_xs, v.xs)
+		sort.Slice(sorted_xs, func(i, j int) bool {
+			return sorted_xs[i] < sorted_xs[j]
+		})
+
+		low := sorted_xs[N_SAMPLES/20]
+		high := sorted_xs[N_SAMPLES*19/20]
+		fmt.Printf("=> ")
+		pretty.PrettyPrint2Floats(low, high)
+
+		fmt.Printf(" (")
+		pretty.PrettyPrintInt(N_SAMPLES)
+		fmt.Printf(" samples)")
+		fmt.Println()
 	default:
-		fmt.Printf("%v", v)
+		fmt.Printf("%v\n", v)
 	}
 }
 
-// Parse line into Distribution
+func printAndReturnErr(err_msg string) error {
-func parseLineErr(err_msg string) (string, Dist, error) {
-	fmt.Println(GENERAL_ERR_MSG)
 	fmt.Println(err_msg)
-	var errorDist Dist
+	fmt.Println(HELP_MSG)
-	return "", errorDist, errors.New(err_msg)
+	return errors.New(err_msg)
-}
-
-func parseLineIntoOpAndDist(line string, vars map[string]Dist) (string, Dist, error) {
-
-	words := strings.Split(strings.TrimSpace(line), " ")
-	op := ""
-	var dist Dist
-
-	switch words[0] {
-	case "*", "/", "+", "-":
-		op = words[0]
-		words = words[1:]
-	default:
-		op = "*" // later, change the below to
-	}
-
-	switch len(words) {
-	case 0:
-		return parseLineErr("Operator must have operand; can't operate on nothing")
-	case 1:
-		var_word, var_word_exists := vars[words[0]]
-		single_float, err1 := strconv.ParseFloat(words[0], 64) // abstract this away to search for K/M/B/T/etc.
-		switch {
-		case var_word_exists:
-			dist = var_word
-		case err1 == nil:
-			dist = Scalar(single_float)
-		case err1 != nil && !var_word_exists:
-			return parseLineErr("Trying to operate on a scalar, but scalar is neither a float nor an assigned variable")
-		}
-	case 2:
-		new_low, err1 := strconv.ParseFloat(words[0], 64)
-		new_high, err2 := strconv.ParseFloat(words[1], 64)
-		if err1 != nil || err2 != nil {
-			return parseLineErr("Trying to operate by a distribution, but distribution is not specified as two floats")
-		}
-		dist = Lognormal{low: new_low, high: new_high}
-	case 3:
-		if words[0] == "beta" || words[0] == "b" {
-			a, err1 := strconv.ParseFloat(words[1], 64)
-			b, err2 := strconv.ParseFloat(words[2], 64)
-			if err1 != nil || err2 != nil {
-				return parseLineErr("Trying to specify a beta distribution? Try beta 1 2")
-			}
-			dist = Beta{a: a, b: b}
-		} else {
-			return parseLineErr("Input not understood or not implemented yet")
-		}
-	default:
-		return parseLineErr("Input not understood or not implemented yet")
-	}
-	return op, dist, nil
-
-}
-
-func multiplyLogDists(l1 Lognormal, l2 Lognormal) Lognormal {
-	logmean1 := (math.Log(l1.high) + math.Log(l1.low)) / 2.0
-	logstd1 := (math.Log(l1.high) - math.Log(l1.low)) / (2.0 * NORMAL90CONFIDENCE)
-
-	logmean2 := (math.Log(l2.high) + math.Log(l2.low)) / 2.0
-	logstd2 := (math.Log(l2.high) - math.Log(l2.low)) / (2.0 * NORMAL90CONFIDENCE)
-
-	logmean_product := logmean1 + logmean2
-	logstd_product := math.Sqrt(logstd1*logstd1 + logstd2*logstd2)
-
-	h := logstd_product * NORMAL90CONFIDENCE
-	loglow := logmean_product - h
-	loghigh := logmean_product + h
-	return Lognormal{low: math.Exp(loglow), high: math.Exp(loghigh)}
-
-}
-
-func multiplyBetaDists(beta1 Beta, beta2 Beta) Beta {
-	return Beta{a: beta1.a + beta2.a, b: beta1.b + beta2.b}
 }
 
+/* Operations */
+// Generic operations with samples
 func operateDistsAsSamples(dist1 Dist, dist2 Dist, op string) (Dist, error) {
 
 	xs := dist1.Samples()
 	ys := dist2.Samples()
-	// fmt.Printf("xs: %v\n", xs)
-	// fmt.Printf("ys: %v\n", ys)
 	zs := make([]float64, N_SAMPLES)
 
 	for i := 0; i < N_SAMPLES; i++ {
@@ -243,6 +166,28 @@ func operateDistsAsSamples(dist1 Dist, dist2 Dist, op string) (Dist, error) {
 	return FilledSamples{xs: zs}, nil
 }
 
+// Multiplication
+func multiplyLogDists(l1 Lognormal, l2 Lognormal) Lognormal {
+	logmean1 := (math.Log(l1.high) + math.Log(l1.low)) / 2.0
+	logstd1 := (math.Log(l1.high) - math.Log(l1.low)) / (2.0 * NORMAL90CONFIDENCE)
+
+	logmean2 := (math.Log(l2.high) + math.Log(l2.low)) / 2.0
+	logstd2 := (math.Log(l2.high) - math.Log(l2.low)) / (2.0 * NORMAL90CONFIDENCE)
+
+	logmean_product := logmean1 + logmean2
+	logstd_product := math.Sqrt(logstd1*logstd1 + logstd2*logstd2)
+
+	h := logstd_product * NORMAL90CONFIDENCE
+	loglow := logmean_product - h
+	loghigh := logmean_product + h
+	return Lognormal{low: math.Exp(loglow), high: math.Exp(loghigh)}
+
+}
+
+func multiplyBetaDists(beta1 Beta, beta2 Beta) Beta {
+	return Beta{a: beta1.a + beta2.a, b: beta1.b + beta2.b}
+}
+
 func multiplyDists(old_dist Dist, new_dist Dist) (Dist, error) {
 
 	switch o := old_dist.(type) {
@@ -291,9 +236,17 @@ func divideDists(old_dist Dist, new_dist Dist) (Dist, error) {
 			switch n := new_dist.(type) {
 			case Lognormal:
 				// to do: check division by zero
+				if n.high == 0 || n.low == 0 {
+					fmt.Println("Error: Can't divide by 0.0")
+					return nil, errors.New("Error: division by zero")
+				}
 				return multiplyLogDists(o, Lognormal{low: 1.0 / n.high, high: 1.0 / n.low}), nil
 			case Scalar:
 				// to do: check division by zero
+				if n == 0.0 {
+					fmt.Println("Error: Can't divide by 0.0")
+					return nil, errors.New("Error: division by zero scalar")
+				}
 				return multiplyLogDists(o, Lognormal{low: 1.0 / float64(n), high: 1.0 / float64(n)}), nil
 			default:
 				return operateDistsAsSamples(old_dist, new_dist, "/")
@@ -306,6 +259,10 @@ func divideDists(old_dist Dist, new_dist Dist) (Dist, error) {
 				return multiplyLogDists(Lognormal{low: float64(o), high: float64(o)}, Lognormal{low: 1.0 / n.high, high: 1.0 / n.low}), nil
 			case Scalar:
 				// to do: check division by zero
+				if n == 0.0 {
+					fmt.Println("Error: Can't divide by 0.0")
+					return nil, errors.New("Error: division by zero scalar")
+				}
 				return Scalar(float64(o) / float64(n)), nil
 			default:
 				return operateDistsAsSamples(old_dist, new_dist, "/")
@@ -316,94 +273,136 @@ func divideDists(old_dist Dist, new_dist Dist) (Dist, error) {
 	}
 }
 
-/* Combine old dist and new line */
+// Generic distribution operations
-// We want this as a function to be able to have parenthesis/recusion, possibly functions
+func operateDists(old_dist Dist, new_dist Dist, op string) (Dist, error) {
-func operateStackWithDist(stack Stack, new_dist Dist, op string) Stack {
-
-	var combined_dist Dist
-	var err error
 	switch op {
 	case "*":
-		if combined_dist, err = multiplyDists(stack.old_dist, new_dist); err == nil {
+		return multiplyDists(old_dist, new_dist)
-			stack.old_dist = combined_dist
-		}
 	case "/":
-		if combined_dist, err = divideDists(stack.old_dist, new_dist); err == nil {
+		return divideDists(old_dist, new_dist)
-			stack.old_dist = combined_dist
-		}
 	case "+":
-		if combined_dist, err = operateDistsAsSamples(stack.old_dist, new_dist, "+"); err == nil {
+		return operateDistsAsSamples(old_dist, new_dist, "+")
-			stack.old_dist = combined_dist
-		}
 	case "-":
-		if combined_dist, err = operateDistsAsSamples(stack.old_dist, new_dist, "-"); err == nil {
+		return operateDistsAsSamples(old_dist, new_dist, "-")
-			stack.old_dist = combined_dist
+	default:
+		return nil, printAndReturnErr("Can't combine distributions in this way")
+	}
+}
+
+/* Parser and repl */
+func parseLineIntoOpAndDist(line string, vars map[string]Dist) (string, Dist, error) {
+
+	words := strings.Split(strings.TrimSpace(line), " ")
+	op := ""
+	var dist Dist
+
+	switch words[0] {
+	case "*", "/", "+", "-":
+		op = words[0]
+		words = words[1:]
+	default:
+		op = "*" // later, change the below to
+	}
+
+	parseLineErr := func(err_msg string) (string, Dist, error) {
+		return "", nil, printAndReturnErr(err_msg)
+	}
+
+	switch len(words) {
+	case 0:
+		return parseLineErr("Operator must have operand; can't operate on nothing")
+	case 1:
+		var_word, var_word_exists := vars[words[0]]
+		single_float, err1 := strconv.ParseFloat(words[0], 64) // abstract this away to search for K/M/B/T/etc.
+		switch {
+		case var_word_exists:
+			dist = var_word
+		case err1 == nil:
+			dist = Scalar(single_float)
+		case err1 != nil && !var_word_exists:
+			return parseLineErr("Trying to operate on a scalar, but scalar is neither a float nor an assigned variable")
+		}
+	case 2:
+		new_low, err1 := strconv.ParseFloat(words[0], 64)
+		new_high, err2 := strconv.ParseFloat(words[1], 64)
+		if err1 != nil || err2 != nil {
+			return parseLineErr("Trying to operate by a distribution, but distribution is not specified as two floats")
+		}
+		dist = Lognormal{low: new_low, high: new_high}
+	case 3:
+		if words[0] == "beta" || words[0] == "b" {
+			a, err1 := strconv.ParseFloat(words[1], 64)
+			b, err2 := strconv.ParseFloat(words[2], 64)
+			if err1 != nil || err2 != nil {
+				return parseLineErr("Trying to specify a beta distribution? Try beta 1 2")
+			}
+			dist = Beta{a: a, b: b}
+		} else {
+			return parseLineErr("Input not understood or not implemented yet")
 		}
 	default:
-		fmt.Println("Can't combine distributions in this way")
+		return parseLineErr("Input not understood or not implemented yet")
 	}
-	return stack
+	return op, dist, nil
 
 }
 
-func runRepl(stack Stack, reader *bufio.Reader) Stack {
+/* Combine old dist and new line */
+// We want this as a function (rather than just be in main)
+// to be able to have parenthesis/recusion, possibly functions
 
+func runRepl(stack Stack, reader *bufio.Reader) Stack {
 replForLoop:
 	for {
 		new_line, _ := reader.ReadString('\n')
 		words := strings.Split(strings.TrimSpace(new_line), " ")
 		switch {
-		/* Empty line case */
+		case strings.TrimSpace(new_line) == "": /* Empty line case */
-		case strings.TrimSpace(new_line) == "":
-			continue replForLoop
 		/* Parenthesis */
 		case len(words) == 2 && (words[0] == "*" || words[0] == "+" || words[0] == "-" || words[0] == "/") && words[1] == "(":
-			new_stack := runRepl(Stack{old_dist: INIT_DIST, vars: stack.vars}, reader) // to do: think if I want to shadow variables or not (right now, variables persist, since I'm copying the map(.
+			new_stack := runRepl(Stack{old_dist: INIT_DIST, vars: stack.vars}, reader)
-			stack = operateStackWithDist(stack, new_stack.old_dist, words[0])
+			combined_dist, err := operateDists(stack.old_dist, new_stack.old_dist, words[0])
-			prettyPrintDist(stack.old_dist)
+			if err == nil {
+				stack.old_dist = combined_dist
+			}
 		case len(words) == 1 && words[0] == ")":
 			return stack
 		/* Special operations */
 		case words[0] == "exit" || words[0] == "e":
 			os.Exit(0)
 		case words[0] == "help" || words[0] == "h":
-			fmt.Println(GENERAL_ERR_MSG)
+			fmt.Println(HELP_MSG)
-			continue replForLoop
 		case words[0] == "debug" || words[0] == "d":
-			fmt.Printf("Old dist: %v\n", stack.old_dist)
+			fmt.Printf("%v", stack)
-			fmt.Printf("Vars: %v\n", stack.vars)
-			continue replForLoop
 		case words[0] == "clear" || words[0] == "c" || words[0] == ".":
 			stack.old_dist = INIT_DIST
 			fmt.Println()
-			continue replForLoop
 		/* Variable assignment */
 		case words[0] == "=:" && len(words) == 2:
 			stack.vars[words[1]] = stack.old_dist
 			fmt.Printf("%s ", words[1])
-			prettyPrintDist(stack.old_dist)
-			continue replForLoop
 		case words[0] == "=." && len(words) == 2:
 			stack.vars[words[1]] = stack.old_dist
 			fmt.Printf("%s ", words[1])
 			prettyPrintDist(stack.old_dist)
 			stack.old_dist = INIT_DIST
-			fmt.Println()
+			// fmt.Println()
-			continue replForLoop
+			// continue replForLoop
 		default:
 			op, new_dist, err := parseLineIntoOpAndDist(new_line, stack.vars)
 			if err != nil {
 				continue replForLoop
 			}
-			stack = operateStackWithDist(stack, new_dist, op)
+			combined_dist, err := operateDists(stack.old_dist, new_dist, op)
-			prettyPrintDist(stack.old_dist)
+			if err == nil {
+				stack.old_dist = combined_dist
 			}
 		}
+		prettyPrintDist(stack.old_dist)
+	}
 }
 
-/* Main event loop */
 func main() {
-
 	reader := bufio.NewReader(os.Stdin)
 	stack := Stack{old_dist: INIT_DIST, vars: make(map[string]Dist)}
 	runRepl(stack, reader)

pretty/pretty.go

@@ -48,5 +48,4 @@ func PrettyPrint2Floats(low float64, high float64) {
 	PrettyPrintFloat(low)
 	fmt.Printf(" ")
 	PrettyPrintFloat(high)
-	fmt.Printf("\n")
 }