From c60430fc1c5d90ae06d1fd019257474c8f395bef Mon Sep 17 00:00:00 2001
From: Jaron Kent-Dobias <jaron@kent-dobias.com>
Date: Fri, 5 Nov 2021 17:31:10 +0100
Subject: Lots of progress towards Hessian implementation.

---
 tensor.hpp | 12 ++++++++++++
 1 file changed, 12 insertions(+)

(limited to 'tensor.hpp')

diff --git a/tensor.hpp b/tensor.hpp
index 1d90c78..aa33069 100644
--- a/tensor.hpp
+++ b/tensor.hpp
@@ -123,3 +123,15 @@ Matrix<Scalar> contractDown(const Tensor<Scalar, r>& J, const Vector<Scalar>& z)
   Tensor<Scalar, r - 1> Jz = J.contract(zT, ip00);
   return contractDown(Jz, z);
 }
+
+template <int f, class Scalar>
+Tensor<Scalar, f> contractDownTo(const Tensor<Scalar, f>& J, const Vector<Scalar>& z) {
+  return J;
+}
+
+template <int f, class Scalar, int r>
+Tensor<Scalar, f> contractDownTo(const Tensor<Scalar, r>& J, const Vector<Scalar>& z) {
+  Tensor<Scalar, 1> zT = Eigen::TensorMap<Tensor<const Scalar, 1>>(z.data(), {z.size()});
+  Tensor<Scalar, r - 1> Jz = J.contract(zT, ip00);
+  return contractDownTo<f>(Jz, z);
+}
-- 
cgit v1.2.3-54-g00ecf