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Task/Statistics-Basic/Go/statistics-basic-1.go

@@ -0,0 +1,41 @@
+package main
+
+import (
+    "fmt"
+    "math"
+    "math/rand"
+    "strings"
+)
+
+func main() {
+    sample(100)
+    sample(1000)
+    sample(10000)
+}
+
+func sample(n int) {
+    // generate data
+    d := make([]float64, n)
+    for i := range d {
+        d[i] = rand.Float64()
+    }
+    // show mean, standard deviation
+    var sum, ssq float64
+    for _, s := range d {
+        sum += s
+        ssq += s * s
+    }
+    fmt.Println(n, "numbers")
+    m := sum / float64(n)
+    fmt.Println("Mean:  ", m)
+    fmt.Println("Stddev:", math.Sqrt(ssq/float64(n)-m*m))
+    // show histogram
+    h := make([]int, 10)
+    for _, s := range d {
+        h[int(s*10)]++
+    }
+    for _, c := range h {
+        fmt.Println(strings.Repeat("*", c*205/int(n)))
+    }
+    fmt.Println()
+}