Merge pull request #1 from davidg238/master

min/max, changes + tests

Author: Informaticore

src/ringbuffer.toit

@@ -17,22 +17,34 @@ class RingBuffer:
     head = (head + 1) % size_
     count = min (count + 1) size_
 
-  min value1 value2:
-    if value1 < value2:
-      return value1
-    return value2
+  is_empty -> bool:
+    return count == 0
+
+  reduce [block]:
+    if is_empty: throw "Not enough elements"
+    result := null
+    is_first := true
+    for i := 0; i < count; i++:
+      if is_first: result = buffer[i]; is_first = false
+      else: result = block.call result buffer[i]
+    return result
+
+  minimum -> float:
+    return reduce : | a b | min a b
+
+  maximum -> float:
+    return reduce : | a b | max a b
 
   average -> float:
-    average := 0.0
-    for i := 0; i <= count - 1; i++:
-      average += buffer[i]
-    return average/count
+    sum := reduce : | a b | a + b
+    return sum / count
 
   std_deviation -> float:
-    variance := 0.0
-    for i := 0; i < count; i++:
-      variance += math.pow (buffer[i] - average) 2
-    
+    if is_empty: throw "Not enough elements"
+    if count < 2:
+      return 0.0 //if there is only one entry return 0.0
+    avg := average
+    variance := reduce : | a b | a += math.pow (b - avg) 2
     return math.sqrt variance / size_
 
   get_last -> float:

test/test_ringbuffer.toit

@@ -4,7 +4,14 @@ import ringbuffer show *
 class TestRingbuffer implements TestCase:
 
   run:
+    test_ringbuffer_average_on_empty_exception
+    test_ringbuffer_minimum_on_empty_exception
+    test_ringbuffer_maximum_on_empty_exception
+    test_ringbuffer_deviation_on_empty_exception
+    test_ringbuffer_one_element
     test_ringbuffer_average
+    test_ringbuffer_minimum
+    test_ringbuffer_maximum
     test_ringbuffer_max
     test_ringbuffer_limit
     test_ringbuffer_get_last
@@ -13,6 +20,39 @@ class TestRingbuffer implements TestCase:
   name -> string:
     return "TestRingbuffer"
 
+  test_ringbuffer_average_on_empty_exception:
+    ringbuffer := RingBuffer 3
+    exception := catch:
+      ringbuffer.average //average
+    assertException exception
+
+  test_ringbuffer_minimum_on_empty_exception:
+    ringbuffer := RingBuffer 3
+    exception := catch:
+      ringbuffer.minimum //minimum
+    assertException exception
+  
+  test_ringbuffer_maximum_on_empty_exception:
+    ringbuffer := RingBuffer 3
+    exception := catch:
+      ringbuffer.maximum //maximum
+    assertException exception
+
+  test_ringbuffer_deviation_on_empty_exception:
+    ringbuffer := RingBuffer 3
+    exception := catch:
+      ringbuffer.std_deviation //std_deviation
+    assertException exception
+
+  test_ringbuffer_one_element:
+    ringbuffer := RingBuffer 3
+    ringbuffer.append 2.3
+    assertEquals 2.3 ringbuffer.average 
+    assertEquals 2.3 ringbuffer.minimum 
+    assertEquals 2.3 ringbuffer.maximum 
+    assertEquals 0.0 ringbuffer.std_deviation
+
+
   test_ringbuffer_average:
     ringbuffer := RingBuffer 3
     ringbuffer.append 1.0
@@ -23,6 +63,24 @@ class TestRingbuffer implements TestCase:
     ringbuffer.append 3.0
     assertEquals 3.0 ringbuffer.average "RingBuffer average function test OK"
 
+  test_ringbuffer_minimum:
+    ringbuffer := RingBuffer 3
+    ringbuffer.append 1.0
+    ringbuffer.append 2.0
+    ringbuffer.append 3.0
+    assertEquals 1.0 ringbuffer.minimum "RingBuffer minimum function test OK"
+    ringbuffer.append 4.0
+    assertEquals 2.0 ringbuffer.minimum "RingBuffer minimum function test OK"
+
+  test_ringbuffer_maximum:
+    ringbuffer := RingBuffer 3
+    ringbuffer.append 1.0
+    ringbuffer.append 2.0
+    ringbuffer.append 3.0
+    assertEquals 3.0 ringbuffer.maximum "RingBuffer maximum function test OK"
+    ringbuffer.append -3.0
+    assertEquals 3.0 ringbuffer.maximum "RingBuffer maximum function test OK"
+
   test_ringbuffer_max:
     ringbuffer := RingBuffer 5
     ringbuffer.append 1.0
@@ -36,7 +94,7 @@ class TestRingbuffer implements TestCase:
   test_ringbuffer_limit:
     exception := catch:
       ringbuffer := RingBuffer -1
-    assertException "RingBuffer size must be larger then 0" 
+    assertException exception
 
   test_ringbuffer_get_last:
     ringbuffer := RingBuffer 5