Merge fc8b32d into 6e25dc5

data.go

@@ -1,5 +1,11 @@
 package stats
 
+import (
+	"fmt"
+	"sort"
+	"strconv"
+)
+
 // Float64Data is a named type for []float64 with helper methods
 type Float64Data []float64
 
@@ -167,3 +173,63 @@ func (f Float64Data) Entropy() (float64, error) {
 func (f Float64Data) Quartiles() (Quartiles, error) {
 	return Quartile(f)
 }
+
+func (f Float64Data) Count() int {
+	return len(f)
+}
+
+// Describe generate descriptive statistics. Return an error only if FloatData is empty.
+func (f Float64Data) Describe(percentiles ...int) error {
+	mean, err := f.Mean()
+	if err != nil {
+		return err
+	}
+
+	// Indentation for readability.
+	const indent = 8
+
+	out := fmt.Sprintf("count %*s %d", indent-len("count"), "", f.Count())
+	fmt.Println(out)
+
+	out = fmt.Sprintf("mean %*s %f", indent-len("mean"), "", mean)
+	fmt.Println(out)
+
+	std, _ := f.StandardDeviation()
+	out = fmt.Sprintf("std %*s %f", indent-len("std"), "", std)
+	fmt.Println(out)
+
+	min, _ := f.Min()
+	out = fmt.Sprintf("min %*s %f", indent-len("min"), "", min)
+	fmt.Println(out)
+
+	// Percentiles.
+	mp := make(map[int]bool)
+	for _, p := range percentiles {
+		mp[p] = true
+	}
+
+	// check if defaults values are in the slice if not add them.
+	var pDefault = []int{25, 50, 75}
+	for _, d := range pDefault {
+		if _, ok := mp[d]; !ok {
+			percentiles = append(percentiles, d)
+		}
+	}
+	sort.Ints(percentiles)
+
+	for _, p := range percentiles {
+		v, _ := f.Percentile(float64(p))
+
+		out = fmt.Sprintf("%.d%% %*s %f", p, indent-len(strconv.FormatInt(int64(p), 10))-1, "", v)
+		fmt.Println(out)
+	}
+
+	max, _ := f.Max()
+	out = fmt.Sprintf("max %*s %f", indent-len("max"), "", max)
+	fmt.Println(out)
+
+	out = fmt.Sprintf("dtype %*s %T", indent-len("dtype"), "", f[0])
+	fmt.Println(out)
+
+	return nil
+}

data_test.go

@@ -1,6 +1,7 @@
 package stats_test
 
 import (
+	"errors"
 	"math"
 	"math/rand"
 	"reflect"
@@ -276,3 +277,23 @@ func TestQuartilesMethods(t *testing.T) {
 		t.Errorf("%s returned an error", getFunctionName(data1.Quartiles))
 	}
 }
+
+func TestDescribe(t *testing.T) {
+	df := stats.Float64Data{1, 2, 3, 4, 10, 80, 123, 83, 48, 30}
+	err := df.Describe()
+	if err != nil {
+		t.Errorf("%s returned an error", getFunctionName(data1.Quartiles))
+	}
+
+	err = df.Describe(1, 5, 10, 90)
+	if err != nil {
+		t.Errorf("%s returned an error", getFunctionName(data1.Quartiles))
+	}
+
+	df = stats.Float64Data{}
+	err = df.Describe()
+	if !errors.Is(err, stats.ErrEmptyInput) {
+		t.Errorf("error: %s ", err.Error())
+	}
+
+}