From 04c52c6c1a91716f4c3ca7d8a2f897a770505fe9 Mon Sep 17 00:00:00 2001
From: rykeenan <ryan.keenan@udacity.com>
Date: Sun, 4 Jun 2017 17:05:10 -0700
Subject: [PATCH] update rover_coords()

---
 code/Rover_Project_Test_Notebook.ipynb | 17 +++++++++--------
 code/perception.py                     |  6 +++---
 2 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/code/Rover_Project_Test_Notebook.ipynb b/code/Rover_Project_Test_Notebook.ipynb
index 67207cb4d6..de3bb2546d 100644
--- a/code/Rover_Project_Test_Notebook.ipynb
+++ b/code/Rover_Project_Test_Notebook.ipynb
@@ -5795,13 +5795,14 @@
     {
       "cell_type": "code",
       "source": [
+        "# Define a function to convert from image coords to rover coords\n",
         "def rover_coords(binary_img):\n",
         "    # Identify nonzero pixels\n",
         "    ypos, xpos = binary_img.nonzero()\n",
         "    # Calculate pixel positions with reference to the rover position being at the \n",
         "    # center bottom of the image.  \n",
-        "    x_pixel = np.absolute(ypos - binary_img.shape[0]).astype(np.float)\n",
-        "    y_pixel = -(xpos - binary_img.shape[0]).astype(np.float)\n",
+        "    x_pixel = -(ypos - binary_img.shape[0]).astype(np.float)\n",
+        "    y_pixel = -(xpos - binary_img.shape[1]/2 ).astype(np.float)\n",
         "    return x_pixel, y_pixel\n",
         "\n",
         "# Define a function to convert to radial coords in rover space\n",
@@ -9261,16 +9262,16 @@
       "display_name": "Python 3"
     },
     "language_info": {
-      "pygments_lexer": "ipython3",
+      "nbconvert_exporter": "python",
       "version": "3.5.2",
+      "file_extension": ".py",
       "name": "python",
-      "mimetype": "text/x-python",
+      "pygments_lexer": "ipython3",
       "codemirror_mode": {
-        "version": 3,
-        "name": "ipython"
+        "name": "ipython",
+        "version": 3
       },
-      "file_extension": ".py",
-      "nbconvert_exporter": "python"
+      "mimetype": "text/x-python"
     }
   },
   "nbformat": 4,
diff --git a/code/perception.py b/code/perception.py
index ed04437804..acf479ddab 100644
--- a/code/perception.py
+++ b/code/perception.py
@@ -17,14 +17,14 @@ def color_thresh(img, rgb_thresh=(160, 160, 160)):
     # Return the binary image
     return color_select
 
-# Define a function to convert to rover-centric coordinates
+# Define a function to convert from image coords to rover coords
 def rover_coords(binary_img):
     # Identify nonzero pixels
     ypos, xpos = binary_img.nonzero()
     # Calculate pixel positions with reference to the rover position being at the 
     # center bottom of the image.  
-    x_pixel = np.absolute(ypos - binary_img.shape[0]).astype(np.float)
-    y_pixel = -(xpos - binary_img.shape[0]).astype(np.float)
+    x_pixel = -(ypos - binary_img.shape[0]).astype(np.float)
+    y_pixel = -(xpos - binary_img.shape[1]/2 ).astype(np.float)
     return x_pixel, y_pixel