From 2f68ab112d8ef389766505887ed291b39c9ec9ef Mon Sep 17 00:00:00 2001
From: Paul Romano <paul.k.romano@gmail.com>
Date: Fri, 19 Jul 2019 09:09:59 -0500
Subject: [PATCH] Update use of xtensor within code

---
 src/eigenvalue.cpp    | 5 +++--
 src/mesh.cpp          | 4 ++--
 src/photon.cpp        | 9 +++------
 src/settings.cpp      | 3 +--
 src/tallies/tally.cpp | 6 ++----
 5 files changed, 11 insertions(+), 16 deletions(-)

diff --git a/src/eigenvalue.cpp b/src/eigenvalue.cpp
index a0b7f82c5f..894157c5b0 100644
--- a/src/eigenvalue.cpp
+++ b/src/eigenvalue.cpp
@@ -572,8 +572,9 @@ void ufs_count_sites()
     // distributed so that effectively the production of fission sites is not
     // biased
 
-    auto s = xt::view(simulation::source_frac, xt::all());
-    s = simulation::ufs_mesh->volume_frac_;
+    std::size_t n = simulation::ufs_mesh->n_bins();
+    double vol_frac = simulation::ufs_mesh->volume_frac_;
+    simulation::source_frac = xt::xtensor<double, 1>({n}, vol_frac);
 
   } else {
     // count number of source sites in each ufs mesh cell
diff --git a/src/mesh.cpp b/src/mesh.cpp
index 9e27fc4e6a..590df53e17 100644
--- a/src/mesh.cpp
+++ b/src/mesh.cpp
@@ -155,8 +155,8 @@ RegularMesh::RegularMesh(pugi::xml_node node)
     fatal_error("Must specify either <upper_right> and <width> on a mesh.");
   }
 
-  // TODO: Change to zero when xtensor is updated
-  if (shape_.size() > 1) {
+  // Make sure lower_left and dimension match
+  if (shape_.size() > 0) {
     if (shape_.size() != lower_left_.size()) {
       fatal_error("Number of entries on <lower_left> must be the same "
         "as the number of entries on <dimension>.");
diff --git a/src/photon.cpp b/src/photon.cpp
index 929822bfcf..a2365de5f3 100644
--- a/src/photon.cpp
+++ b/src/photon.cpp
@@ -181,8 +181,7 @@ PhotonInteraction::PhotonInteraction(hid_t group, int i_element)
   read_dataset(rgroup, "J", profile_pdf_);
 
   // Get Compton profile momentum grid. By deafult, an xtensor has a size of 1.
-  // TODO: Change to zero when xtensor is updated
-  if (data::compton_profile_pz.size() == 1) {
+  if (data::compton_profile_pz.size() == 0) {
     read_dataset(rgroup, "pz", data::compton_profile_pz);
   }
   close_group(rgroup);
@@ -213,8 +212,7 @@ PhotonInteraction::PhotonInteraction(hid_t group, int i_element)
     // Get energy grids used for bremsstrahlung DCS and for stopping powers
     xt::xtensor<double, 1> electron_energy;
     read_dataset(rgroup, "electron_energy", electron_energy);
-    // TODO: Change to zero when xtensor is updated
-    if (data::ttb_k_grid.size() == 1) {
+    if (data::ttb_k_grid.size() == 0) {
       read_dataset(rgroup, "photon_energy", data::ttb_k_grid);
     }
 
@@ -255,8 +253,7 @@ PhotonInteraction::PhotonInteraction(hid_t group, int i_element)
     }
 
     // Set incident particle energy grid
-    // TODO: Change to zero when xtensor is updated
-    if (data::ttb_e_grid.size() == 1) {
+    if (data::ttb_e_grid.size() == 0) {
       data::ttb_e_grid = electron_energy;
     }
 
diff --git a/src/settings.cpp b/src/settings.cpp
index 796a2862ad..b647d32e86 100644
--- a/src/settings.cpp
+++ b/src/settings.cpp
@@ -512,8 +512,7 @@ void read_settings_xml()
     if (!m) fatal_error("Only regular meshes can be used as an entropy mesh");
     simulation::entropy_mesh = m;
 
-    // TODO: Change to zero when xtensor is updated
-    if (m->shape_.size() == 1) {
+    if (m->shape_.size() == 0) {
       // If the user did not specify how many mesh cells are to be used in
       // each direction, we automatically determine an appropriate number of
       // cells
diff --git a/src/tallies/tally.cpp b/src/tallies/tally.cpp
index eea43989ef..852918a0cd 100644
--- a/src/tallies/tally.cpp
+++ b/src/tallies/tally.cpp
@@ -810,8 +810,7 @@ void Tally::init_results()
 void Tally::reset()
 {
   n_realizations_ = 0;
-  // TODO: Change to zero when xtensor is updated
-  if (results_.size() != 1) {
+  if (results_.size() != 0) {
     xt::view(results_, xt::all()) = 0.0;
   }
 }
@@ -1399,8 +1398,7 @@ openmc_tally_results(int32_t index, double** results, size_t* shape)
   }
 
   const auto& t {model::tallies[index]};
-  // TODO: Change to zero when xtensor is updated
-  if (t->results_.size() == 1) {
+  if (t->results_.size() == 0) {
     set_errmsg("Tally results have not been allocated yet.");
     return OPENMC_E_ALLOCATE;
   }