diff --git a/stim/cuda/conv2.cuh b/stim/cuda/conv2.cuh
index 4e778e5..a40fdd0 100644
--- a/stim/cuda/conv2.cuh
+++ b/stim/cuda/conv2.cuh
@@ -17,7 +17,7 @@ namespace stim{
 
 
 			//the radius of mask
-			unsigned r = (M - 1)/2;
+			int r = (M - 1)/2;
 
 
 			//calculate the 1D index for this thread
@@ -32,7 +32,7 @@ namespace stim{
 
 			if(i < w && j < h){
 
-				//copy[idx] = tex2D<float>(texObj, i, j);
+				//copy[idx] = tex2D<float>(texObj, i+100, j+100);
 				//return;
 
 				//tex2D<float>(texObj, i, j);
@@ -49,12 +49,12 @@ namespace stim{
 					for (int x = i - r; x <= i + r; x++){
 
 						//idx to mask cordinates(xx, yy)
-						unsigned int xx = x - (i - r);
-						unsigned int yy = y - (j - r);
+						int xx = x - (i - r);
+						int yy = y - (j - r);
 
 						//T temp = img[y * w + x] * mask[yy * M + xx];
 						//sum += img[y * w + x] * mask[yy * M + xx];
-						sum += tex2D<T>(texObj, x-50, y+100) * mask[yy * M + xx];
+						sum += tex2D<T>(texObj, x, y) * 1.0;//mask[yy * M + xx];
 					}		
 				}
 				copy[idx] = sum;
--
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