I have reached checkpoint #2.

I had the most trouble with the last 2. I just had to play around with
different formats of the same thing until I got the results I wanted. I was
able to complete this fairly quickly and didn't have much trouble.

transform.py

@@ -6,38 +6,69 @@
 
 def maximum(data):
     "Returns the largest number in data"
-    raise NotImplementedError
+    greatest=None
+    for number in data:
+        if greatest is None:
+            greatest=number
+        if number>greatest:
+            greatest=number
+    return greatest
 
 def minimum(data):
     "Returns the smallest number in data"
-    raise NotImplementedError
+    lowest=None
+    for number in data:
+        if lowest is None:
+            lowest=number
+        if number<lowest:
+            lowest=number
+    return lowest
 
 def bounds(data):
     "Returns a list of the smallest and largest numbers in data"
-    raise NotImplementedError
+    greatest=None
+    for number in data:
+        if greatest is None:
+            greatest=number
+        if number>greatest:
+            greatest=number
+    lowest=None
+    for number in data:
+        if lowest is None:
+            lowest=number
+        if number<lowest:
+            lowest=number
+    return [lowest, greatest]
 
 def clamp(value, low, high):
     """Clamps a value to a range from low to high. 
     Returns value if it is between low and high.
     If value is lower than low, returns low. If value is higher than high, returns high.
     """
-    raise NotImplementedError
+    if value<low: 
+        return low
+    if value>high:
+        return high
+    else:
+        return value
 
 def ratio(value, start, end):
     """Returns a number from 0.0 to 1.0, representing how far along value is from start to end.
     The return value is clamped to [0, 1], so even if value is lower than start, the return 
     value will not be lower than 0.0.
     """
-    raise NotImplementedError
+    r=(value-start)/(end-start)
+    return clamp(r, 0, 1)
 
 def scale(value, domain_min, domain_max, range_min, range_max):
     "Given a value within a domain, returns the scaled equivalent within range."
-    raise NotImplementedError
+    r=(value-domain_min)/(domain_max-domain_min)
+    return range_min+r*(range_max-range_min)
 
 def get_x_values(points):
     "Returns the first value for each point in points."
-    raise NotImplementedError
+    return [x for [x, y] in points]
-
 def get_y_values(points):
     "Returns the second value for each point in points."
-    raise NotImplementedError
+    return [y for [x, y] in points]
+