diff --git a/src/chainable.h b/src/chainable.h
index 9fe6d208..885efdbd 100644
--- a/src/chainable.h
+++ b/src/chainable.h
@@ -17,6 +17,8 @@ struct Chainable {
     virtual void set_zero_adjoint() { }
 
     virtual void allocate(size_t) = 0;
+    virtual std::string graphviz() = 0;
+
     
     virtual const Shape& shape() = 0;
     virtual DataType &val() = 0;
diff --git a/src/expression_graph.h b/src/expression_graph.h
index f0d5f233..7a766679 100644
--- a/src/expression_graph.h
+++ b/src/expression_graph.h
@@ -50,6 +50,18 @@ class ExpressionGraph {
         v->forward();    
     }
     
+    std::string graphviz() {
+      std::stringstream ss;
+      ss << "digraph ExpressionGraph {" << std::endl;
+      ss << "rankdir=BT" << std::endl;
+      
+      typedef typename ChainableStack::reverse_iterator It;
+      for(It it = stack_->rbegin(); it != stack_->rend(); ++it)
+        ss << (*it)->graphviz();
+      ss << "}" << std::endl;
+      return ss.str();
+    }
+    
     void backward() {
       for(auto&& v : *stack_)
         v->set_zero_adjoint();
diff --git a/src/node_operators.h b/src/node_operators.h
index e5cf2110..8620a645 100644
--- a/src/node_operators.h
+++ b/src/node_operators.h
@@ -22,6 +22,13 @@ struct InputNode : public Node {
 
   void forward() {}
   void backward() {}
+  
+  virtual std::string graphviz() {
+    std::stringstream ss;
+    ss << "\"" << this << "\" [shape=\"parallelogram\", label=\"input\", style=\"filled\", fillcolor=\"lawngreen\"]" << std::endl << std::endl;
+    return ss.str();
+  };
+
 };
 
 struct ConstantNode : public Node {
@@ -35,6 +42,13 @@ struct ConstantNode : public Node {
 
   void forward() {}
   void backward() {}
+
+  virtual std::string graphviz() {
+    std::stringstream ss;
+    ss << "\"" << this << "\" [shape=\"diamond\", label=\"const\"]" << std::endl << std::endl;
+    return ss.str();
+  };
+
 };
 
 struct ParamNode : public Node {
@@ -60,6 +74,13 @@ struct ParamNode : public Node {
     }
   }
 
+  virtual std::string graphviz() {
+    std::stringstream ss;
+    ss << "\"" << this << "\" [shape=\"hexagon\", label=\"param\", style=\"filled\", fillcolor=\"orangered\"]" << std::endl << std::endl;
+    return ss.str();
+  };
+
+  
   private:
     std::function<void(Tensor)> init_;
     bool initialized_;
@@ -89,6 +110,14 @@ struct LogitNodeOp : public UnaryNodeOp {
     Element(_1 += _2 * _3 * (1 - _3),
             a_->grad(), adj_, val_);
   }
+
+  virtual std::string graphviz() {
+    std::stringstream ss;
+    ss << "\"" << this << "\" [shape=\"box\", label=\"logit\", style=\"filled\", fillcolor=\"yellow\"]" << std::endl;
+    ss << "\"" << &*a_ << "\" -> \"" << this << "\"" << std::endl << std::endl;
+    return ss.str();
+  };
+
 };
 
 struct TanhNodeOp : public UnaryNodeOp {
@@ -105,6 +134,14 @@ struct TanhNodeOp : public UnaryNodeOp {
     Element(_1 += _2 * (1 - _3 * _3),
             a_->grad(), adj_, val_);
   }
+
+  virtual std::string graphviz() {
+    std::stringstream ss;
+    ss << "\"" << this << "\" [shape=\"box\", label=\"tanh\", style=\"filled\", fillcolor=\"yellow\"]" << std::endl;
+    ss << "\"" << &*a_ << "\" -> \"" << this << "\"" << std::endl << std::endl;
+    return ss.str();
+  };
+
 };
 
 // @TODO, make this numerically safe(r):
@@ -131,6 +168,14 @@ struct SoftmaxNodeOp : public UnaryNodeOp {
     SubtractMean(&result, val_);
     Element(_1 += _2 *  _3, a_->grad(), val_, result);
   }
+
+  virtual std::string graphviz() {
+    std::stringstream ss;
+    ss << "\"" << this << "\" [shape=\"box\", label=\"softmax\", style=\"filled\", fillcolor=\"yellow\"]" << std::endl;
+    ss << "\"" << &*a_ << "\" -> \"" << this << "\"" << std::endl << std::endl;
+    return ss.str();
+  };
+
 };
 
 struct LogNodeOp : public UnaryNodeOp {
@@ -146,6 +191,14 @@ struct LogNodeOp : public UnaryNodeOp {
     Element(_1 += _2 * 1.f / _3,
             a_->grad(), adj_, a_->val());
   }
+  
+  virtual std::string graphviz() {
+    std::stringstream ss;
+    ss << "\"" << this << "\" [shape=\"box\", label=\"log\", style=\"filled\", fillcolor=\"yellow\"]" << std::endl;
+    ss << "\"" << &*a_ << "\" -> \"" << this << "\"" << std::endl << std::endl;
+    return ss.str();
+  };
+
 };
 
 struct ExpNodeOp : public UnaryNodeOp {
@@ -161,6 +214,14 @@ struct ExpNodeOp : public UnaryNodeOp {
     Element(_1 += _2 * Exp(_3),
             a_->grad(), adj_, a_->val());
   }
+  
+  virtual std::string graphviz() {
+    std::stringstream ss;
+    ss << "\"" << this << "\" [shape=\"box\", label=\"exp\", style=\"filled\", fillcolor=\"yellow\"]" << std::endl;
+    ss << "\"" << &*a_ << "\" -> \"" << this << "\"" << std::endl << std::endl;
+    return ss.str();
+  };
+
 };
 
 struct NegNodeOp : public UnaryNodeOp {
@@ -175,6 +236,14 @@ struct NegNodeOp : public UnaryNodeOp {
   void backward() {
     Element(_1 += -_2, a_->grad(), adj_);
   }
+  
+  virtual std::string graphviz() {
+    std::stringstream ss;
+    ss << "\"" << this << "\" [shape=\"box\", label=\"-\", style=\"filled\", fillcolor=\"yellow\"]" << std::endl;
+    ss << "\"" << &*a_ << "\" -> \"" << this << "\"" << std::endl << std::endl;
+    return ss.str();
+  };
+
 };
 
 /******************************************************/
@@ -220,6 +289,15 @@ struct DotNodeOp : public BinaryNodeOp {
     Prod(a_->grad(), adj_, b_->val(), false, true, 1.0);
     Prod(b_->grad(), a_->val(), adj_, true, false, 1.0);
   }
+  
+  virtual std::string graphviz() {
+    std::stringstream ss;
+    ss << "\"" << this << "\" [shape=\"box\", label=\"×\", style=\"filled\", fillcolor=\"orange\"]" << std::endl;
+    ss << "\"" << &*a_ << "\" -> \"" << this << "\"" << std::endl;
+    ss << "\"" << &*b_ << "\" -> \"" << this << "\"" << std::endl << std::endl;
+    return ss.str();
+  };
+
 };
 
 struct PlusNodeOp : public BinaryNodeOp {
@@ -238,6 +316,15 @@ struct PlusNodeOp : public BinaryNodeOp {
     Element(_1 += _2,
             b_->grad(), adj_);
   }
+
+  virtual std::string graphviz() {
+    std::stringstream ss;
+    ss << "\"" << this << "\" [shape=\"box\", label=\"+\", style=\"filled\", fillcolor=\"yellow\"]" << std::endl;
+    ss << "\"" << &*a_ << "\" -> \"" << this << "\"" << std::endl;
+    ss << "\"" << &*b_ << "\" -> \"" << this << "\"" << std::endl << std::endl;
+    return ss.str();
+  };
+
 };
 
 struct MinusNodeOp : public BinaryNodeOp {
@@ -256,6 +343,15 @@ struct MinusNodeOp : public BinaryNodeOp {
     Element(_1 -= _2,
             b_->grad(), adj_);
   }
+  
+  virtual std::string graphviz() {
+    std::stringstream ss;
+    ss << "\"" << this << "\" [shape=\"box\", label=\"-\", style=\"filled\", fillcolor=\"yellow\"]" << std::endl;
+    ss << "\"" << &*a_ << "\" -> \"" << this << "\"" << std::endl;
+    ss << "\"" << &*b_ << "\" -> \"" << this << "\"" << std::endl << std::endl;
+    return ss.str();
+  };
+
 };
 
 struct MultNodeOp : public BinaryNodeOp {
@@ -274,6 +370,15 @@ struct MultNodeOp : public BinaryNodeOp {
     Element(_1 += _2 * _3,
             b_->grad(), adj_, a_->val());
   }
+  
+  virtual std::string graphviz() {
+    std::stringstream ss;
+    ss << "\"" << this << "\" [shape=\"box\", label=\"•\", style=\"filled\", fillcolor=\"yellow\"]" << std::endl;
+    ss << "\"" << &*a_ << "\" -> \"" << this << "\"" << std::endl;
+    ss << "\"" << &*b_ << "\" -> \"" << this << "\"" << std::endl << std::endl;
+    return ss.str();
+  };
+
 };
 
 struct DivNodeOp : public BinaryNodeOp {
@@ -291,7 +396,16 @@ struct DivNodeOp : public BinaryNodeOp {
             a_->grad(), adj_, b_->val());
     Element(_1 -= _2 * _3 / (_4 * _4),
             b_->grad(), adj_, a_->val(), b_->val());
-  }  
+  }
+  
+  virtual std::string graphviz() {
+    std::stringstream ss;
+    ss << "\"" << this << "\" [shape=\"box\", label=\"÷\", style=\"filled\", fillcolor=\"yellow\"]" << std::endl;
+    ss << "\"" << a_ << "\" -> \"" << this << "\"" << std::endl;
+    ss << "\"" << b_ << "\" -> \"" << this << "\"" << std::endl << std::endl;
+    return ss.str();
+  };
+
 };
 
 }
diff --git a/src/test.cu b/src/test.cu
index d27591be..f3bcef11 100644
--- a/src/test.cu
+++ b/src/test.cu
@@ -75,6 +75,8 @@ int main(int argc, char** argv) {
     Y[t] = Yt;
   }
 
+  std::cout << g.graphviz() << std::endl;
+  
   g.forward(batch_size);
   g.backward();
 
diff --git a/src/validate_mnist.cu b/src/validate_mnist.cu
index cbd3e0a3..f71be921 100644
--- a/src/validate_mnist.cu
+++ b/src/validate_mnist.cu
@@ -47,7 +47,7 @@ ExpressionGraph build_graph() {
 
 int main(int argc, char** argv) {
   
-  cudaSetDevice(1);
+  cudaSetDevice(0);
     
   std::cerr << "Loading test set...";
   std::vector<float> testImages = datasets::mnist::ReadImages("../examples/mnist/t10k-images-idx3-ubyte", BATCH_SIZE, IMAGE_SIZE);
@@ -62,6 +62,8 @@ int main(int argc, char** argv) {
   g["x"] = (xt << testImages);
   g["y"] = (yt << testLabels);
   
+  std::cout << g.graphviz() << std::endl;
+  
   g.forward(BATCH_SIZE);
  
   std::vector<float> results;