Data update

Task/Statistics-Normal-distribution/Yabasic/statistics-normal-distribution.basic

@@ -0,0 +1,73 @@
+normalStats(100)
+print
+normalStats(1000)
+print
+normalStats(10000)
+print
+normalStats(100000)
+end
+
+sub randomNormal()
+    local u1, u2
+	u1 = ran()
+    u2 = ran()
+    return cos(2 * pi * u1) * sqrt(-2 * log(u2))
+end sub
+
+sub normalStats(n)
+    local r(n), h(11)
+    local i, sum, hSum, mean, sd, scale, stars
+	sum = 0
+    hSum = 0
+
+    // Generate samples: mean 0.5, std 0.25
+    for i = 1 to n
+        r(i) = 0.5 + randomNormal() / 4
+        sum = sum + r(i)
+
+        if r(i) < 0 then
+            h(0) = h(0) + 1
+        elsif r(i) >= 1 then
+            h(11) = h(11) + 1
+        else
+            h(int(r(i)*10)+1) = h(int(r(i)*10)+1) + 1
+        fi
+    next i
+
+    for i = 0 to 11
+        hSum = hSum + h(i)
+    next i
+
+    mean = sum / n
+
+    // Standard deviation
+    sum = 0
+    for i = 1 to n
+        sum = sum + (r(i) - mean)^2
+    next i
+    sd = sqrt(sum / n)
+
+    print "Sample size ", n
+    print
+    print "  Mean ", mean using("#.######");
+    print "  SD ", sd using("#.######")
+    print
+
+    // Histogram (scale for large samples)
+    scale = 1
+    if n > 300  scale = 300 / n
+
+    for i = 0 to 11
+        if i = 0 then
+            print "< 0.00  : ", h(0) using("#####"), " ";
+        elsif i = 11 then
+            print ">=1.00  : ", h(1) using("#####");
+        else
+            //print using("  #.##  : ##### ", (i-1)/10); h(i);
+			print "  ", (i-1)/10 using("#.##"), "  : ", h(i) using("#####"), " ";
+        fi
+
+        stars = int(h(i) * scale + 0.5)
+        print string$(stars, "*")
+    next i
+end sub