add spike-distance, PWL function (probably buggy)

1 files changed, 31 insertions, 2 deletions

diff --git a/pyspike/function.py b/pyspike/function.py
index c1de9cb..adf4dbb 100644
--- a/pyspike/function.py
+++ b/pyspike/function.py
@@ -44,8 +44,6 @@ class PieceWiseConstFunc:
         Returns:
         - the average a. 
         """
-        print(self.x)
-        print(self.y)
         return np.sum((self.x[1:]-self.x[:-1]) * self.y) / \
             (self.x[-1]-self.x[0])
 
@@ -58,3 +56,34 @@ class PieceWiseConstFunc:
         """
         return np.sum((self.x[1:]-self.x[:-1]) * np.abs(self.y)) / \
             (self.x[-1]-self.x[0])
+
+
+class PieceWiseLinFunc:
+    """ A class representing a piece-wise linear function. """
+    
+    def __init__(self, x, y1, y2):
+        """ Constructs the piece-wise linear function.
+        Params:
+        - x: array of length N+1 defining the edges of the intervals of the pwc
+        function.
+        - y1: array of length N defining the function values at the left of the 
+        intervals.
+        - y2: array of length N defining the function values at the right of the 
+        intervals.
+        """
+        self.x = x
+        self.y1 = y1
+        self.y2 = y2
+
+    def get_plottable_data(self):
+        """ Returns two arrays containing x- and y-coordinates for immeditate
+        plotting of the piece-wise function.
+        """
+        x_plot = np.empty(2*len(self.x)-2)
+        x_plot[0] = self.x[0]
+        x_plot[1::2] = self.x[1:]
+        x_plot[2::2] = self.x[1:-1]
+        y_plot = np.empty_like(x_plot)
+        y_plot[0::2] = self.y1
+        y_plot[1::2] = self.y2
+        return x_plot, y_plot