Data commit

Task/Random-numbers/Eiffel/random-numbers.e

@@ -0,0 +1,95 @@
+class
+	APPLICATION
+
+inherit
+	ARGUMENTS
+
+create
+	make
+
+feature {NONE} -- Initialization
+
+	l_time: TIME
+	l_seed: INTEGER
+	math:DOUBLE_MATH
+	rnd:RANDOM
+	Size:INTEGER
+		once
+			Result:= 1000
+		end
+
+	make
+			-- Run application.
+		local
+			ergebnis:ARRAY[DOUBLE]
+			tavg: DOUBLE
+			x: INTEGER
+			tmp: DOUBLE
+			text : STRING
+
+		do
+			-- initialize random generator
+			create l_time.make_now
+     		        l_seed := l_time.hour
+      		        l_seed := l_seed * 60 + l_time.minute
+      		        l_seed := l_seed * 60 + l_time.second
+      		        l_seed := l_seed * 1000 + l_time.milli_second
+      		        create rnd.set_seed (l_seed)
+
+			-- initialize random number container and math
+			create ergebnis.make_filled (0.0, 1, size)
+			tavg := 0;
+			create math
+
+			from
+				x := 1
+			until
+				x > ergebnis.count
+			loop
+				tmp := randomNormal / 2 + 1
+				tavg := tavg + tmp
+				ergebnis.enter (tmp , x)
+				x := x + 1
+			end
+
+			tavg := tavg / ergebnis.count
+			text := "Average: "
+			text.append_double (tavg)
+			text.append ("%N")
+			print(text)
+
+			tmp := 0
+			from
+				x:= 1
+			until
+				x > ergebnis.count
+			loop
+				tmp := tmp + (ergebnis.item (x) - tavg)^2
+				x := x + 1
+			end
+
+			tmp := math.sqrt (tmp / ergebnis.count)
+			text := "Standard Deviation: "
+			text.append_double (tmp)
+			text.append ("%N")
+			print(text)
+
+		end
+
+	randomNormal:DOUBLE
+
+		local
+
+      		        first: DOUBLE
+      		        second: DOUBLE
+
+		do
+                        rnd.forth
+                        first := rnd.double_item
+                        rnd.forth
+                        second := rnd.double_item
+
+                        Result := math.cosine (2 * math.pi * first) * math.sqrt (-2 * math.log (second))
+
+		end
+end