From 3f14bc3af7af2fd5770431c4790f8a71b062c366 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Tue, 14 Jul 2026 00:57:24 +0000
Subject: [PATCH] fix: Add vote accumulation logic to hough_transform_polar.m

Co-authored-by: tsainez <13399044+tsainez@users.noreply.github.com>
---
 matlab/hough_transform_polar.m | 110 ++++++++++++++++++---------------
 1 file changed, 61 insertions(+), 49 deletions(-)

diff --git a/matlab/hough_transform_polar.m b/matlab/hough_transform_polar.m
index 58904ab..69f8485 100644
--- a/matlab/hough_transform_polar.m
+++ b/matlab/hough_transform_polar.m
@@ -1,50 +1,62 @@
-function [r, theta] = hough_transform_polar(edge_map)
-
-    %% find x, y position from edge map
-    [edge_y, edge_x] = find(edge_map);
-    
-    %% range of r
-    H = size(edge_map, 1);
-    W = size(edge_map, 2);
-    
-    r_max = round(sqrt(H^2 + W^2));
-    r_min = -r_max;
-    r_step = 1;
-    r_range = r_min : r_step : r_max;
-    
-    %% range of theta
-    theta_step = 0.01;
-    theta_range = -pi/2 : theta_step : pi/2;
-    
-    %% create vote matrix
-    V = zeros(length(r_range), length(theta_range));
-    
-    %% TODO: add votes
-%     V(1, 1) = 1; % remove this line
-    for i = 1:length(edge_y)
-        x = edge_x(i);
-        y = edge_y(i);
-        for theta_index = 1:length(theta_range)
-            theta = theta_range(theta_index);
-            r = x * cos(theta) + y * sin(theta);
-            if r_min <= r
-                if r <= r_max
-                    r_index = round((r - r_min) / r_step) + 1;
-                    V(r_index, theta_index) = V(r_index, theta_index) + 1;
-                end
-            end
-        end
-    end
-    
-    
-
-    %% visualize votes
-%     figure, imagesc(V); xlabel('theta'); ylabel('r');
-    
-    %% find the maximal vote
-    max_vote = max(V(:));
-    [max_r_index, max_theta_index] = find( V == max_vote );
-    r = r_range(max_r_index);
-    theta = theta_range(max_theta_index);
-
+function [r, theta] = hough_transform_polar(edge_map)
+    % HOUGH_TRANSFORM_POLAR Performs the Hough Transform to detect lines using polar coordinates.
+    %
+    %   [r, theta] = HOUGH_TRANSFORM_POLAR(edge_map) takes a binary edge map image as input
+    %   and returns the distance from the origin (r) and angle (theta) of the most prominent line
+    %   detected in the image.
+    %
+    %   Inputs:
+    %       edge_map - A binary matrix representing the edge map of an image,
+    %                  where non-zero values indicate edge pixels.
+    %
+    %   Outputs:
+    %       r - The distance from the origin to the detected line.
+    %       theta - The angle of the normal to the detected line.
+
+    %% find x, y position from edge map
+    [edge_y, edge_x] = find(edge_map);
+
+    %% range of r
+    H = size(edge_map, 1);
+    W = size(edge_map, 2);
+
+    r_max = round(sqrt(H^2 + W^2));
+    r_min = -r_max;
+    r_step = 1;
+    r_range = r_min : r_step : r_max;
+
+    %% range of theta
+    theta_step = 0.01;
+    theta_range = -pi/2 : theta_step : pi/2;
+
+    %% create vote matrix
+    V = zeros(length(r_range), length(theta_range));
+
+    %% add votes
+    for i = 1:length(edge_y)
+        x = edge_x(i);
+        y = edge_y(i);
+        for theta_index = 1:length(theta_range)
+            theta = theta_range(theta_index);
+            r = x * cos(theta) + y * sin(theta);
+            if r_min <= r
+                if r <= r_max
+                    r_index = round((r - r_min) / r_step) + 1;
+                    V(r_index, theta_index) = V(r_index, theta_index) + 1;
+                end
+            end
+        end
+    end
+
+
+
+    %% visualize votes
+%     figure, imagesc(V); xlabel('theta'); ylabel('r');
+
+    %% find the maximal vote
+    max_vote = max(V(:));
+    [max_r_index, max_theta_index] = find( V == max_vote );
+    r = r_range(max_r_index);
+    theta = theta_range(max_theta_index);
+
 end
\ No newline at end of file