update examples &c

README.md

@@ -1,33 +1,83 @@
 # A minimalist calculator for fermi estimation
 
-This project contains a minimalist calculator for Fermi estimation. Right now, it just multiplies lognormals.
+This project contains a minimalist command-line calculator for Fermi estimation. For now, it just multiplies lognormals.
 
 ## Motivation
 
 Sometimes, [Squiggle](https://github.com/quantified-uncertainty/squiggle), [simple squiggle](https://git.nunosempere.com/quantified.uncertainty/simple-squiggle) or [squiggle.c](https://git.nunosempere.com/personal/squiggle.c) are still too complicated and un-unix-like.
 
-## An example
+## Usage
 
+Here is an example
 
+```
+$ go run f.go
+5000000 12000000
+=> 5000000.0 12000000.0
+0.002 0.01
+=> 13859.5 86583.4
+30 180
+=> 706832.8 9167656.0
+/ 48 52
+=> 14139.1 183614.7
+/ 5 6
+=> 2573.1 33632.0
+/ 6 8
+=> 368.4 4893.5
+/ 60 60
+=> 6.1 81.6
+```
 
-Perhaps this example might be clearer with comment
+Perhaps this example is more understandable with comments and better units:
 
+```
+$ sed -u "s|#.*||" | sed -u 's|M|000000|g' | go run f.go
+5M 12M # number of people living in Chicago
+=> 5000000.0 12000000.0
+0.002 0.01 # fraction of people that have a piano
+=> 13859.5 86583.4
+30 180 # minutes it takes to tune a piano, including travel time
+=> 706832.8 9167656.0
+/ 48 52 # weeks a year that piano tuners work for
+=> 14139.1 183614.7
+/ 5 6 # days a week in which piano tuners work
+=> 2573.1 33632.0
+/ 6 8 # hours a day in which piano tuners work
+=> 368.4 4893.5
+/ 60 60 # minutes to an hour
+=> 6.1 81.6
+# ^ piano tuners in Chicago
+```
 
-## 
+## Installation
 
-To do:
+```
+make build
+sudo make install
+f # rather than the previous go run f.go
+```
 
-- [ ] Write README
-- [ ] Add show more info version
-- [ ] Add division?
-- [ ] Read from file?
-- [ ] Save to file?
+Why use make instead of the built-in go commands? Because the point of make is to be able to share command-line recipes. 
+
+## Usage together with standard Linux utilities
+
+```
+f
+ed -u "s|#.*||" | sed -u 's|M|000000|g' | f
+cat more/piano-tuners.f | f
+cat more/piano-tuners-commented.f | sed -u "s|#.*||" | sed -u 's|M|000000|g' | f
+tee -a input.log | go run f.go | tee -a output.log
+tee -a io.log | go run f.go | tee -a io.log
+```
+
+## Roadmap 
+
+- [x] Write README
+- [x] Add division?
+- [x] Read from file?
+- [x] Save to file?
+- [x] Allow comments?
+  - [x] Use a sed filter? 
+- [x] Add show more info version
 - [ ] Program into a small device, like a calculator?
-- [ ] Allow comments?
-  - Use a sed filter? 
 - [ ] Think of some way of calling bc
-
-
-go run main.go < model.f
-sed 's|//||' model.f | go run main.go
-

f.go

@@ -41,31 +41,33 @@ func combineBounds(old_low, old_high, new_low, new_high float64) (float64, float
 }
 
 func main() {
-	reader := bufio.NewReader(os.Stdin)
 	var old_low, old_high float64
 
+	reader := bufio.NewReader(os.Stdin)
 	input, _ := reader.ReadString('\n')
 	input = strings.TrimSpace(input)
-
 	tokens := strings.Split(input, " ")
+	error_msg_start := "Please enter two floats separated by a space, like: 1 10"
 	if len(tokens) != 2 {
-		fmt.Println("Please enter two floats separated by a space")
+		fmt.Println(error_msg_start)
 		return
 	}
 	old_low, err1 := strconv.ParseFloat(tokens[0], 64)
 	old_high, err2 := strconv.ParseFloat(tokens[1], 64)
 	if err1 != nil || err2 != nil {
-		fmt.Println("Invalid input. Please ensure you enter two floats.")
+		fmt.Println(error_msg_start)
 		return
 	}
 
 	fmt.Printf("=> %.1f %.1f\n", old_low, old_high)
 
+	error_msg_cont := "Please enter two floats separated by a space, like: 1 10, or two floats preceded by a division, like: / 2 20. Or enter i to get the logmean and logstd"
+EventForLoop:
 	for {
 		// fmt.Println("Enter another two floats separated by a space:")
 		input, _ = reader.ReadString('\n')
 		if strings.TrimSpace(input) == "" {
-			break // Exit if no input is given
+			continue EventForLoop
 		}
 
 		tokens := strings.Split(strings.TrimSpace(input), " ")
@@ -74,15 +76,20 @@ func main() {
 		var new_low, new_high float64
 		switch len(tokens) {
 		case 0:
-			continue
+			continue EventForLoop
 		case 1:
-			continue
+			if tokens[0] == "i" {
+				fmt.Printf("=> %.1f %.1f\n", old_low, old_high)
+				logmean_old, logstd_old := boundsToLogParams(old_low, old_high)
+				fmt.Printf("=> Lognormal, with logmean: %.1f, logstd: %.1f\n", logmean_old, logstd_old)
+			}
+			continue EventForLoop
 		case 2:
 			new_low, err1 = strconv.ParseFloat(tokens[0], 64)
 			new_high, err2 = strconv.ParseFloat(tokens[1], 64)
 			if err1 != nil || err2 != nil {
-				fmt.Println("Invalid input. Please ensure you enter two floats.")
-				continue
+				fmt.Println(error_msg_cont)
+				continue EventForLoop
 			}
 		case 3:
 			switch tokens[0] {
@@ -90,23 +97,26 @@ func main() {
 				new_low, err1 = strconv.ParseFloat(tokens[1], 64)
 				new_high, err2 = strconv.ParseFloat(tokens[2], 64)
 				if err1 != nil || err2 != nil {
-					fmt.Println("Invalid input. Please ensure you enter two floats.")
-					continue
+					fmt.Println(error_msg_cont)
+					continue EventForLoop
 				}
 			case "/":
 				new_low, err1 = strconv.ParseFloat(tokens[1], 64)
 				new_high, err2 = strconv.ParseFloat(tokens[2], 64)
 				if err1 != nil || err2 != nil {
-					fmt.Println("Invalid input. Please ensure you enter two floats.")
-					continue
+					fmt.Println(error_msg_cont)
+					continue EventForLoop
 				}
 				tmp_low := new_low
 				new_low = 1.0 / new_high
 				new_high = 1.0 / tmp_low
 			default:
-				continue
+				fmt.Println(error_msg_cont)
+				continue EventForLoop
 			}
-
+		default:
+			fmt.Println(error_msg_cont)
+			continue EventForLoop
 		}
 		// Use the abstracted function for combining floats
 		old_low, old_high = combineBounds(old_low, old_high, new_low, new_high)

more/piano-tuners-commented.f

@@ -0,0 +1,9 @@
+5M 12M # number of people living in Chicago
+0.002 0.01 # fraction of people that have a piano
+30 180 # minutes it takes to tune a piano, including travel time
+/ 48 52 # weeks a year that piano tuners work for
+/ 5 6 # days a week in which piano tuners work
+/ 6 8 # hours a day in which piano tuners work
+/ 60 60 # minutes to an hour
+# ^ piano tuners in Chicago
+

more/piano-tuners.f

@@ -0,0 +1,7 @@
+5000000 12000000
+0.002 0.01
+30 180
+/ 48 52
+/ 5 6
+/ 6 8
+/ 60 60