add seq-stat: terminal histogram generator for number sequences

Generates ASCII histograms using Unicode block characters for sequences
of numbers provided via command line arguments or STDIN input.

1 files changed, 115 insertions, 0 deletions

diff --git a/cmd/seq-stat/main.go b/cmd/seq-stat/main.go
new file mode 100644
index 0000000..75bb0a3
--- /dev/null
+++ b/cmd/seq-stat/main.go
@@ -0,0 +1,115 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+var ticks = []rune{'▁', '▂', '▃', '▄', '▅', '▆', '▇', '█'}
+
+func histogram(sequence []float64) []rune {
+	if len(sequence) == 0 {
+		return []rune{}
+	}
+
+	minVal := sequence[0]
+	maxVal := sequence[0]
+
+	for _, v := range sequence {
+		if v < minVal {
+			minVal = v
+		}
+		if v > maxVal {
+			maxVal = v
+		}
+	}
+
+	scale := (maxVal - minVal) * 256 / float64(len(ticks)-1)
+	if scale < 1 {
+		scale = 1
+	}
+
+	result := make([]rune, len(sequence))
+	for i, v := range sequence {
+		index := int(((v - minVal) * 256) / scale)
+		if index >= len(ticks) {
+			index = len(ticks) - 1
+		}
+		result[i] = ticks[index]
+	}
+
+	return result
+}
+
+func parseNumbers(input string) ([]float64, error) {
+	fields := strings.Fields(input)
+	numbers := make([]float64, 0, len(fields))
+
+	for _, field := range fields {
+		num, err := strconv.ParseFloat(field, 64)
+		if err != nil {
+			return nil, fmt.Errorf("invalid number: %s", field)
+		}
+		numbers = append(numbers, num)
+	}
+
+	return numbers, nil
+}
+
+func readFromStdin() ([]float64, error) {
+	var numbers []float64
+	scanner := bufio.NewScanner(os.Stdin)
+
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if line == "" {
+			continue
+		}
+
+		lineNumbers, err := parseNumbers(line)
+		if err != nil {
+			return nil, err
+		}
+		numbers = append(numbers, lineNumbers...)
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, fmt.Errorf("error reading from stdin: %v", err)
+	}
+
+	return numbers, nil
+}
+
+func main() {
+	var numbers []float64
+	var err error
+
+	if len(os.Args) > 1 {
+		numbers = make([]float64, 0, len(os.Args)-1)
+		for _, arg := range os.Args[1:] {
+			num, parseErr := strconv.ParseFloat(arg, 64)
+			if parseErr != nil {
+				fmt.Fprintf(os.Stderr, "Invalid number: %s\n", arg)
+				os.Exit(1)
+			}
+			numbers = append(numbers, num)
+		}
+	} else {
+		numbers, err = readFromStdin()
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+			os.Exit(1)
+		}
+
+		if len(numbers) == 0 {
+			fmt.Fprintln(os.Stderr, "No numbers provided")
+			os.Exit(1)
+		}
+	}
+
+	h := histogram(numbers)
+	fmt.Println(string(h))
+}