feat: Initial version

csv.go

@@ -0,0 +1,49 @@
+package main
+
+import (
+	"encoding/csv"
+	"fmt"
+	"io"
+	"strconv"
+)
+
+type statsFunc func(data []float64) float64
+
+func sum(data []float64) float64 {
+	sum := 0.0
+	for _, v := range data {
+		sum += v
+	}
+	return sum
+}
+
+func avg(data []float64) float64 {
+	return sum(data) / float64(len(data))
+}
+
+func csv2float(r io.Reader, column int) ([]float64, error) {
+	cr := csv.NewReader(r)
+	if column < 1 {
+		return nil, fmt.Errorf("%w: please provide a valid column number", ErrInvalidColumn)
+	}
+	column--
+	allData, err := cr.ReadAll()
+	if err != nil {
+		return nil, fmt.Errorf("cannot read data from file: %w", err)
+	}
+	var data []float64
+	for i, row := range allData {
+		if i == 0 {
+			continue
+		}
+		if len(row) <= column {
+			return nil, fmt.Errorf("%w: File has only %d columns", ErrInvalidColumn, len(row))
+		}
+		v, err := strconv.ParseFloat(row[column], 64)
+		if err != nil {
+			return nil, fmt.Errorf("%w: %s", ErrNotNumber, err)
+		}
+		data = append(data, v)
+	}
+	return data, nil
+}