Divide broadcast

Author: cbovar

src/ConvNetSharp.Volume.GPU/Double/Kernels/div.cu

@@ -1,6 +1,12 @@
 extern "C" {
-    __global__ void Run(int n, double* __restrict left, double* __restrict right, double* __restrict output) {
+    __global__ void Run(int n, double* __restrict left, double* __restrict right, double* __restrict output, int rightIsScalar) {
 		int i = blockIdx.x*blockDim.x + threadIdx.x;
-		if (i < n) output[i] = left[i] / right[i];
+		if (i < n) {
+            if (rightIsScalar == 1) { 
+                output[i] = left[i] / right[0];
+            } else {
+                output[i] = left[i] / right[i];
+            }
+        }
 	}
 }

src/ConvNetSharp.Volume.GPU/Double/Volume.cs

@@ -406,7 +406,7 @@ public override void ConvolutionGradient(Volume<double> filters, Volume<double>
 
         public override void Divide(Volume<double> other, Volume<double> result)
         {
-            _kernelLoader.RunKernel("div", this, other, result);
+            _kernelLoader.RunKernel("div", this, other, result, other.Shape.TotalLength == 1 ? 1 : 0);
         }
 
         public override void Dropout(double dropProbability, Volume<double> result)

src/ConvNetSharp.Volume.GPU/Single/Kernels/div.cu

@@ -1,6 +1,12 @@
 extern "C" {
-    __global__ void Run(int n, float* __restrict left, float* __restrict right, float* __restrict output) {
+    __global__ void Run(int n, float* __restrict left, float* __restrict right, float* __restrict output, int rightIsScalar) {
 		int i = blockIdx.x*blockDim.x + threadIdx.x;
-		if (i < n) output[i] = left[i] / right[i];
+		if (i < n) {
+            if (rightIsScalar == 1) { 
+                output[i] = left[i] / right[0];
+            } else {
+                output[i] = left[i] / right[i];
+            }
+        }
 	}
 }

src/ConvNetSharp.Volume.GPU/Single/Volume.cs

@@ -414,7 +414,7 @@ public override void ConvolutionGradient(Volume<float> filters, Volume<float> ou
 
         public override void Divide(Volume<float> other, Volume<float> result)
         {
-            _kernelLoader.RunKernel("div", this, other, result);
+            _kernelLoader.RunKernel("div", this, other, result, other.Shape.TotalLength == 1 ? 1 : 0);
         }
 
         public override void Dropout(float dropProbability, Volume<float> result)

src/ConvNetSharp.Volume.Tests/VolumeTests.cs

@@ -61,6 +61,19 @@ public void Div1DInPlace()
             AssertNumber.AreEqual(0.3, left.Get(2), 1e-6);
         }
 
+        [TestMethod]
+        public void Div1DBroadcast()
+        {
+            var left = NewVolume(new[] { 1.0, 2.0, 3.0 }, new Shape(3));
+            var right = NewVolume(new[] { 2.0 }, new Shape(1));
+            var result = BuilderInstance<T>.Volume.SameAs(new Shape(3));
+
+            left.Divide(right, result);
+            AssertNumber.AreEqual(0.5, result.Get(0));
+            AssertNumber.AreEqual(1.0, result.Get(1));
+            AssertNumber.AreEqual(1.5, result.Get(2));
+        }
+
         [TestMethod]
         public void Add2D()
         {

src/ConvNetSharp.Volume/Double/Volume.cs

@@ -255,15 +255,7 @@ public override void ConvolutionGradient(Volume<double> filters, Volume<double>
 
         public override void Divide(Volume<double> other, Volume<double> result)
         {
-            if (this.Shape.Equals(other.Shape))
-            {
-                this.Storage.Map((left, right) => left / right, other.Storage, result.Storage);
-            }
-            else
-            {
-                //Todo: broadcast
-                throw new NotImplementedException();
-            }
+            this.Storage.MapEx((left, right) => left / right, other.Storage, result.Storage);
         }
 
         public override void Dropout(double dropProbability, Volume<double> result)

src/ConvNetSharp.Volume/Single/Volume.cs

@@ -255,15 +255,7 @@ public override void ConvolutionGradient(Volume<float> filters, Volume<float> ou
 
         public override void Divide(Volume<float> other, Volume<float> result)
         {
-            if (this.Shape.Equals(other.Shape))
-            {
-                this.Storage.Map((left, right) => left / right, other.Storage, result.Storage);
-            }
-            else
-            {
-                //Todo: broadcast
-                throw new NotImplementedException();
-            }
+            this.Storage.MapEx((left, right) => left / right, other.Storage, result.Storage);
         }
 
         public override void Dropout(float dropProbability, Volume<float> result)