Draft: Streamline data model

TODO:

• phi convention documentation
• Maybe introduce TrackerHitInfo etc utility classes for links
• Time resolution in tracker hit
• Use 4-vector + 4D diagonal covariance for tracker hit
• Remove redundant "polar" components - could be moved to Info utility class if useful
• Remove most of the ExtraCode for explicit constructors - this should either be a main Podio flag, but won't be necessary in the presence of the Info utility classes
• Rename RICHCluster to RingImage or similar
• Simplify some of the ExtraCode to make yams file look less scary
• Better name for the ImagingXXX classes
• Add momentum to ReconstructedParticle
• Add type to ECAL cluster
• Add weight to ReconstructedParticle

source/include/eicd/helpers.h

 #ifndef EICD_HELPERS_HH
 #define EICD_HELPERS_HH
 
-
 #include <algorithm>
 #include <cmath>
 #include <exception>
@@ -11,33 +10,36 @@
 
 #include <Math/Vector4D.h>
 
-#include "eicd/TrackParametersCollection.h"
 #include "eicd/ReconstructedParticleCollection.h"
 #include "eicd/ReconstructedParticleData.h"
+#include "eicd/TrackParametersCollection.h"
 
 namespace eicd::helpers {
 
-  /** Four momentum from track and mass.
-   * Get a vector of 4-momenta from raw tracking info, using an externally
-   * provided particle mass assumption. 
-   */
-  inline auto momenta_from_tracking(const std::vector<eic::TrackParametersData>& tracks,
-                                    const double                                 mass)
-  {
-    std::vector<ROOT::Math::PxPyPzMVector> momenta{tracks.size()};
-    // transform our raw tracker info into proper 4-momenta
-    std::transform(tracks.begin(), tracks.end(), momenta.begin(), [mass](const auto& track) {
-      // make sure we don't divide by zero
-      if (fabs(track.qOverP) < 1e-9) {
-        return ROOT::Math::PxPyPzMVector{};
-      }
-      const double p  = fabs(1. / track.qOverP);
-      const double px = p * cos(track.phi) * sin(track.theta);
-      const double py = p * sin(track.phi) * sin(track.theta);
-      const double pz = p * cos(track.theta);
-      return ROOT::Math::PxPyPzMVector{px, py, pz, mass};
-    });
-    return momenta;
-  }
+/** Four momentum from track and mass.
+ * Get a vector of 4-momenta from raw tracking info, using an externally
+ * provided particle mass assumption.
+ */
+inline auto
+momenta_from_tracking(const std::vector<eic::TrackParametersData>& tracks,
+                      const double mass) {
+  std::vector<ROOT::Math::PxPyPzMVector> momenta{tracks.size()};
+  // transform our raw tracker info into proper 4-momenta
+  std::transform(
+      tracks.begin(), tracks.end(), momenta.begin(), [mass](const auto& track) {
+        // make sure we don't divide by zero
+        if (fabs(track.qOverP) < 1e-9) {
+          return ROOT::Math::PxPyPzMVector{};
+        }
+        const double p = fabs(1. / track.qOverP);
+        const double px =
+            p * cos(track.direction.phi) * sin(track.direction.theta);
+        const double py =
+            p * sin(track.direction.phi) * sin(track.direction.theta);
+        const double pz = p * cos(track.direction.theta);
+        return ROOT::Math::PxPyPzMVector{px, py, pz, mass};
+      });
+  return momenta;
+}
 } // namespace eicd::helpers
 #endif