Add option to allow instructors to clamp maximum percentage score (#26)

* Added maximum percentage score option

* Simplify code, allow to work with sorted weights.

* updated new variable name to bucket_percentage_upper_clamp

gradeable.h

@@ -65,6 +65,7 @@ class Gradeable {
   // ACCESSORS
   int getCount() const { return count; }
   float getPercent() const { return percent; }
+  float getBucketPercentageUpperClamp() const { return this->bucket_percentage_upper_clamp; }
   float getMaximum() const { 
     if (maximums.size() == 0) return 0;
     assert (maximums.size() > 0);
@@ -162,6 +163,12 @@ class Gradeable {
     return index;
   }
 
+  // Set the max percentage that can be received for a gradeable type.
+  // If the value is less than 0, it should be ignored.
+  void setBucketPercentageUpperClamp(float bucket_percentage_upper_clamp) {
+    this->bucket_percentage_upper_clamp = bucket_percentage_upper_clamp;
+  }
+
   void setCorrespondenceName(const std::string& id, const std::string& name) {
     assert (hasCorrespondence(id));
     assert (correspondences[id].second == "");
@@ -215,6 +222,7 @@ class Gradeable {
   int count;
   float percent;
   int remove_lowest;
+  float bucket_percentage_upper_clamp;
   std::map<std::string,std::pair<int,std::string> > correspondences;
   std::map<std::string,float> maximums;
   std::map<std::string,float> scale_maximums;

main.cpp

@@ -559,6 +559,16 @@ void preprocesscustomizationfile(const std::string &now_string,
     GRADEABLES[g].setRemoveLowest(num);
     ALL_GRADEABLES.push_back(g);
 
+    // Used to clamp extra credit. For example, if there are 3 gradeables of a category, each worth 1/2
+    // percentage of a total score, a student could earn 1.5x the value for the gradeable category.
+    // We can clamp that by setting bucket_percentage_upper_clamp to a value less than 1.5.
+    nlohmann::json::iterator upper_clamp_itr = one_gradeable_type.find("bucket_percentage_upper_clamp");
+    float bucket_percentage_upper_clamp = -1;
+    if (upper_clamp_itr != one_gradeable_type.end()){
+        bucket_percentage_upper_clamp = upper_clamp_itr->get<float>();
+    }
+    GRADEABLES[g].setBucketPercentageUpperClamp(bucket_percentage_upper_clamp);
+
     //Parse out the min grade required for passing in this category
     float overall_cutoff = one_gradeable_type.value("overall_cutoff", 0.0);
     assert(0.0 <= overall_cutoff && overall_cutoff <= 1.0);

student.cpp

@@ -207,12 +207,12 @@ float Student::GradeablePercent(GRADEABLE_ENUM g) const {
     }
   }
 
-  if(GRADEABLES[g].hasSortedWeight()){
-      return 100*sum;
-  }
-  else {
-      return 100 * GRADEABLES[g].getPercent() * sum;
+  float percentage = GRADEABLES[g].hasSortedWeight() ? sum : GRADEABLES[g].getPercent() * sum;
+  float percentage_upper_clamp = GRADEABLES[g].getBucketPercentageUpperClamp();
+  if (percentage_upper_clamp > 0) {
+    percentage = std::min(percentage, percentage_upper_clamp);
   }
+  return 100 * percentage;
 }