add -h flag and document flags

README.md

@@ -90,6 +90,8 @@ help
     exit
 ```
 
+You can see real life examples [here](https://x.com/NunoSempere/status/1831106442721452312), [here](https://x.com/NunoSempere/status/1829525844169248912), [here](https://x.com/NunoSempere/status/1818810770932568308), [here](https://x.com/NunoSempere/status/1816605190415401100), [here](https://x.com/NunoSempere/status/1816604386703081894), [here](https://x.com/NunoSempere/status/1815169781907042504)
+
 ## Tips & tricks
 
 - It's conceptually clearer to have all the multiplications first and then all the divisions

fermi.go

@@ -65,7 +65,8 @@ func (fs FilledSamples) Samples() []float64 {
 }
 
 /* Constants */
-const HELP_MSG = "  Operation | Variable assignment | Special\n" +
+const HELP_MSG = "1. Grammar:\n" +
+	"  Operation | Variable assignment | Special\n" +
 	"    Operation:                             operator operand\n" +
 	"          operator:                        (empty) | * | / | + | -\n" +
 	"          operand:                         scalar | lognormal | beta | variable\n" +
@@ -73,8 +74,9 @@ const HELP_MSG = "  Operation | Variable assignment | Special\n" +
 	"            beta:                          beta alpha beta\n" +
 	"    Variable assignment:                   =: variable_name\n" +
 	"    Variable assignment and clear stack:   =. variable_name\n" +
-	"    Special: \n" +
+	"    Special commands: \n" +
 	"         Comment:                          # this is a comment\n" +
+	"         Summary stats:                    stats\n" +
 	"         Clear stack:                      clear | c | .\n" +
 	"         Print debug info:                 debug | d\n" +
 	"         Print help message:               help  | h\n" +
@@ -98,7 +100,16 @@ const HELP_MSG = "  Operation | Variable assignment | Special\n" +
 	"    1 10\n" +
 	"    + beta 1 100\n" +
 	"    )\n" +
-	"    exit\n"
+	"    exit\n" +
+	"\n" +
+	"2. Command flags:\n" +
+	"  -echo\n" +
+	"        Specifies whether inputs should be echoed back. Useful if reading from a file\n." +
+	"  -f string\n" +
+	"        Specifies a file with a model to run\n" +
+	"  -n int\n" +
+	"        Specifies the number of samples to draw when using samples (default 100000)\n" +
+	"  -h    Shows help message\n"
 
 const NORMAL90CONFIDENCE = 1.6448536269514727
 const INIT_DIST Scalar = Scalar(1)
@@ -122,14 +133,15 @@ func prettyPrintDist(dist Dist) {
 		pretty.PrettyPrintFloat(w)
 		fmt.Println()
 	case FilledSamples:
-		sorted_xs := make([]float64, N_SAMPLES)
+		n := len(v.xs)
+		sorted_xs := make([]float64, n)
 		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]
+		low := sorted_xs[int(math.Round(float64(n)*0.05))]
-		high := sorted_xs[N_SAMPLES*19/20]
+		high := sorted_xs[int(math.Round(float64(n)*0.95))]
 		fmt.Printf("=> ")
 		pretty.PrettyPrint2Floats(low, high)
 
@@ -144,10 +156,50 @@ func prettyPrintDist(dist Dist) {
 
 func printAndReturnErr(err_msg string) error {
 	fmt.Println(err_msg)
-	fmt.Println(HELP_MSG)
+	// fmt.Println(HELP_MSG)
+	fmt.Println("Type \"help\" (without quotes) to see a pseudogrammar and examples")
 	return errors.New(err_msg)
 }
 
+func prettyPrintStats(dist Dist) {
+	xs := dist.Samples()
+	n := len(xs)
+
+	mean := 0.0
+	for i := 0; i < n; i++ {
+		mean += xs[i]
+	}
+	mean /= float64(n)
+	fmt.Printf("Mean:   %f\n", mean)
+
+	stdev := 0.0
+	for i := 0; i < n; i++ {
+		stdev += math.Pow(xs[i]-mean, 2)
+	}
+	stdev = math.Sqrt(stdev / float64(n))
+	fmt.Printf("Stdev:  %f\n", stdev)
+
+	sorted_xs := make([]float64, n)
+	copy(sorted_xs, xs)
+	sort.Slice(sorted_xs, func(i, j int) bool {
+		return sorted_xs[i] < sorted_xs[j]
+	})
+	print_ci := func(ci float64, prefix string) {
+		x := sorted_xs[int(math.Round(float64(n)*ci))]
+		fmt.Printf("%s%f\n", prefix, x)
+	}
+	print_ci(0.01, "ci 1%:  ")
+	print_ci(0.05, "ci 5%:  ")
+	print_ci(0.10, "ci 10%: ")
+	print_ci(0.25, "ci 25%: ")
+	print_ci(0.50, "ci 50%: ")
+	print_ci(0.75, "ci 75%: ")
+	print_ci(0.90, "ci 90%: ")
+	print_ci(0.95, "ci 95%: ")
+	print_ci(0.99, "ci 99%: ")
+
+}
+
 /* Operations */
 // Generic operations with samples
 func operateDistsAsSamples(dist1 Dist, dist2 Dist, op string) (Dist, error) {
@@ -171,6 +223,9 @@ func operateDistsAsSamples(dist1 Dist, dist2 Dist, op string) (Dist, error) {
 			zs[i] = xs[i] + ys[i]
 		case "-":
 			zs[i] = xs[i] - ys[i]
+		default:
+			fmt.Println("Error: Operation not recognized")
+			return nil, errors.New("Operation not recognized")
 		}
 	}
 
@@ -209,8 +264,6 @@ func multiplyDists(old_dist Dist, new_dist Dist) (Dist, error) {
 				return multiplyLogDists(o, n), nil
 			case Scalar:
 				return multiplyLogDists(o, Lognormal{low: float64(n), high: float64(n)}), nil
-			default:
-				return operateDistsAsSamples(old_dist, new_dist, "*")
 			}
 		}
 	case Scalar:
@@ -223,20 +276,15 @@ func multiplyDists(old_dist Dist, new_dist Dist) (Dist, error) {
 				return multiplyLogDists(Lognormal{low: float64(o), high: float64(o)}, n), nil
 			case Scalar:
 				return Scalar(float64(o) * float64(n)), nil
-			default:
-				return operateDistsAsSamples(old_dist, new_dist, "*")
 			}
 		}
 	case Beta:
 		switch n := new_dist.(type) {
 		case Beta:
 			return multiplyBetaDists(o, n), nil
-		default:
-			return operateDistsAsSamples(old_dist, new_dist, "*")
 		}
-	default:
-		return operateDistsAsSamples(old_dist, new_dist, "*")
 	}
+	return operateDistsAsSamples(old_dist, new_dist, "*")
 }
 
 func divideDists(old_dist Dist, new_dist Dist) (Dist, error) {
@@ -257,8 +305,6 @@ func divideDists(old_dist Dist, new_dist Dist) (Dist, error) {
 					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, "/")
 			}
 		}
 	case Scalar:
@@ -272,13 +318,10 @@ func divideDists(old_dist Dist, new_dist Dist) (Dist, error) {
 					return nil, errors.New("Error: division by zero scalar")
 				}
 				return Scalar(float64(o) / float64(n)), nil
-			default:
-				return operateDistsAsSamples(old_dist, new_dist, "/")
 			}
 		}
-	default:
-		return operateDistsAsSamples(old_dist, new_dist, "/")
 	}
+	return operateDistsAsSamples(old_dist, new_dist, "/")
 }
 
 // Generic distribution operations
@@ -389,6 +432,8 @@ replForLoop:
 		case words[0] == "clear" || words[0] == "c" || words[0] == ".":
 			stack.old_dist = INIT_DIST
 			fmt.Println()
+		case words[0] == "stats" || words[0] == "s":
+			prettyPrintStats(stack.old_dist)
 		/* Variable assignment */
 		case words[0] == "=:" && len(words) == 2:
 			stack.vars[words[1]] = stack.old_dist
@@ -416,8 +461,12 @@ func main() {
 	num_samples_flag := flag.Int("n", N_SAMPLES, "Specifies the number of samples to draw when using samples")
 	filename := flag.String("f", "", "Specifies a file with a model to run")
 	echo_flag := flag.Bool("echo", false, "Specifies whether inputs should be echoed back. Useful if reading from a file.")
+	help_flag := flag.Bool("h", false, "Shows help message")
 	flag.Parse()
 	N_SAMPLES = *num_samples_flag
+	if *help_flag {
+		fmt.Println(HELP_MSG)
+	}
 
 	var reader *bufio.Reader = nil
 	if *filename != "" {