updated combined gmm to return tree

src/main/java/gov/usgs/earthquake/nshmp/gmm/CombinedGmm.java

@@ -5,6 +5,7 @@ import static gov.usgs.earthquake.nshmp.gmm.Gmm.ASK_14;
 import static gov.usgs.earthquake.nshmp.gmm.Gmm.ASK_14_BASIN;
 import static gov.usgs.earthquake.nshmp.gmm.Gmm.ATKINSON_08_PRIME;
 import static gov.usgs.earthquake.nshmp.gmm.Gmm.ATKINSON_10;
+import static gov.usgs.earthquake.nshmp.gmm.Gmm.BCHYDRO_12_SLAB;
 import static gov.usgs.earthquake.nshmp.gmm.Gmm.BSSA_14;
 import static gov.usgs.earthquake.nshmp.gmm.Gmm.BSSA_14_BASIN;
 import static gov.usgs.earthquake.nshmp.gmm.Gmm.CAMPBELL_03;
@@ -23,12 +24,12 @@ import static gov.usgs.earthquake.nshmp.gmm.Gmm.SILVA_02;
 import static gov.usgs.earthquake.nshmp.gmm.Gmm.SOMERVILLE_01;
 import static gov.usgs.earthquake.nshmp.gmm.Gmm.TORO_97_MW;
 import static gov.usgs.earthquake.nshmp.gmm.Gmm.TP_05;
+import static gov.usgs.earthquake.nshmp.gmm.Gmm.WONG_15;
 
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.stream.Collectors;
 
-import com.google.common.collect.ImmutableMap;
-
 import gov.usgs.earthquake.nshmp.gmm.GmmInput.Constraints;
 import gov.usgs.earthquake.nshmp.tree.LogicTree;
 
@@ -41,44 +42,34 @@ import gov.usgs.earthquake.nshmp.tree.LogicTree;
 class CombinedGmm implements GroundMotionModel {
 
   private static final String NAME = "Combined: ";
-  private final Map<GroundMotionModel, Double> gmms;
+  private final Map<Gmm, Double> gmms;
+  private final Imt imt;
 
   /* Supply map of ground motion models initialized to the required IMT. */
   private CombinedGmm(Imt imt, Map<Gmm, Double> gmms) {
-    this.gmms = instancesForImt(imt, gmms);
+    this.gmms = gmms;
+    this.imt = imt;
   }
 
   @Override
   public LogicTree<GroundMotion> calc(GmmInput in) {
 
-    Map<GroundMotion, Double> sgms = gmms.entrySet().stream()
-        .collect(Collectors.toMap(
-            entry -> GroundMotions.combine(entry.getKey().calc(in)),
-            Map.Entry::getValue));
-
-    /*
-     * Mean values are converted to linear space for combining and returned to
-     * natural log space upon return.
-     */
-    double μ = sgms.entrySet().stream()
-        .collect(Collectors.summingDouble(
-            entry -> Math.exp(entry.getKey().mean()) * entry.getValue()));
-
-    double σ = sgms.entrySet().stream()
-        .collect(Collectors.summingDouble(
-            entry -> entry.getKey().sigma() * entry.getValue()));
-
-    return GroundMotions.createTree(Math.log(μ), σ);
+    LogicTree.Builder<GroundMotion> builder = LogicTree.builder(NAME);
+    gmms.keySet().forEach(key -> builder.addBranch(
+        key.name(),
+        GroundMotions.combine(key.instance(imt).calc(in)),
+        gmms.get(key)));
+    return builder.build();
   }
 
-  static Map<GroundMotionModel, Double> instancesForImt(
+  static Map<Gmm, GroundMotionModel> instancesForImt(
       Imt imt,
       Map<Gmm, Double> gmms) {
 
     return gmms.entrySet().stream()
         .collect(Collectors.toMap(
-            entry -> entry.getKey().instance(imt),
-            Map.Entry::getValue));
+            Entry::getKey,
+            entry -> entry.getKey().instance(imt)));
   }
 
   /*
@@ -87,11 +78,10 @@ class CombinedGmm implements GroundMotionModel {
    * intersection of all support IMTs.
    */
 
-  private static final Map<Gmm, Double> HI_DEEP_2021 = ImmutableMap.<Gmm, Double> builder()
-      .put(ATKINSON_10, 0.4)
-      .put(Gmm.BCHYDRO_12_SLAB, 0.4)
-      .put(Gmm.WONG_15, 0.2)
-      .build();
+  private static final Map<Gmm, Double> HI_DEEP_2021 = Map.of(
+      ATKINSON_10, 0.4,
+      BCHYDRO_12_SLAB, 0.4,
+      WONG_15, 0.2);
 
   static final class HawaiiDeep2021 extends CombinedGmm {
 
@@ -104,13 +94,12 @@ class CombinedGmm implements GroundMotionModel {
     }
   }
 
-  private static final Map<Gmm, Double> HI_SHALLOW_2021 = ImmutableMap.<Gmm, Double> builder()
-      .put(ATKINSON_10, 0.2)
-      .put(ASK_14, 0.2)
-      .put(BSSA_14, 0.2)
-      .put(CB_14, 0.2)
-      .put(CY_14, 0.2)
-      .build();
+  private static final Map<Gmm, Double> HI_SHALLOW_2021 = Map.of(
+      ATKINSON_10, 0.2,
+      ASK_14, 0.2,
+      BSSA_14, 0.2,
+      CB_14, 0.2,
+      CY_14, 0.2);
 
   static final class HawaiiShallow2021 extends CombinedGmm {
 
@@ -123,17 +112,16 @@ class CombinedGmm implements GroundMotionModel {
     }
   }
 
-  static final Map<Gmm, Double> CEUS_2014_FAULT = ImmutableMap.<Gmm, Double> builder()
-      .put(AB_06_PRIME, 0.22)
-      .put(ATKINSON_08_PRIME, 0.08)
-      .put(CAMPBELL_03, 0.11)
-      .put(FRANKEL_96, 0.06)
-      .put(PEZESHK_11, 0.15)
-      .put(SILVA_02, 0.06)
-      .put(SOMERVILLE_01, 0.1)
-      .put(TP_05, 0.11)
-      .put(TORO_97_MW, 0.11)
-      .build();
+  static final Map<Gmm, Double> CEUS_2014_FAULT = Map.of(
+      AB_06_PRIME, 0.22,
+      ATKINSON_08_PRIME, 0.08,
+      CAMPBELL_03, 0.11,
+      FRANKEL_96, 0.06,
+      PEZESHK_11, 0.15,
+      SILVA_02, 0.06,
+      SOMERVILLE_01, 0.1,
+      TP_05, 0.11,
+      TORO_97_MW, 0.11);
 
   /* Need to allow Vs30=3000 through for comparison plots. */
   private static final Constraints CEUS_2014_CONSTRAINTS = Constraints.builder()
@@ -160,10 +148,9 @@ class CombinedGmm implements GroundMotionModel {
   }
 
   /* 5.0 */
-  private static final Map<Gmm, Double> CEUS_2018 = ImmutableMap.<Gmm, Double> builder()
-      .put(NGA_EAST_USGS, 0.667)
-      .put(NGA_EAST_USGS_SEEDS, 0.333)
-      .build();
+  private static final Map<Gmm, Double> CEUS_2018 = Map.of(
+      NGA_EAST_USGS, 0.667,
+      NGA_EAST_USGS_SEEDS, 0.333);
 
   static final class Ceus2018 extends CombinedGmm {
 
@@ -177,10 +164,9 @@ class CombinedGmm implements GroundMotionModel {
   }
 
   /* 5.0 Gulf Coast */
-  private static final Map<Gmm, Double> CEUS_2018_CPA = ImmutableMap.<Gmm, Double> builder()
-      .put(NGA_EAST_USGS_CPA, 0.667)
-      .put(NGA_EAST_USGS_SEEDS_CPA, 0.333)
-      .build();
+  private static final Map<Gmm, Double> CEUS_2018_CPA = Map.of(
+      NGA_EAST_USGS_CPA, 0.667,
+      NGA_EAST_USGS_SEEDS_CPA, 0.333);
 
   static final class Ceus2018Cpa extends CombinedGmm {
 
@@ -193,13 +179,12 @@ class CombinedGmm implements GroundMotionModel {
     }
   }
 
-  private static final Map<Gmm, Double> WUS_2014_4P1 = ImmutableMap.<Gmm, Double> builder()
-      .put(ASK_14, 0.22)
-      .put(BSSA_14, 0.22)
-      .put(CB_14, 0.22)
-      .put(CY_14, 0.22)
-      .put(IDRISS_14, 0.12)
-      .build();
+  private static final Map<Gmm, Double> WUS_2014_4P1 = Map.of(
+      ASK_14, 0.22,
+      BSSA_14, 0.22,
+      CB_14, 0.22,
+      CY_14, 0.22,
+      IDRISS_14, 0.12);
 
   /* 4.1 */
   static final class Wus2014_4p1 extends CombinedGmm {
@@ -213,12 +198,11 @@ class CombinedGmm implements GroundMotionModel {
     }
   }
 
-  private static final Map<Gmm, Double> WUS_2014_4P2 = ImmutableMap.<Gmm, Double> builder()
-      .put(ASK_14, 0.25)
-      .put(BSSA_14, 0.25)
-      .put(CB_14, 0.25)
-      .put(CY_14, 0.25)
-      .build();
+  private static final Map<Gmm, Double> WUS_2014_4P2 = Map.of(
+      ASK_14, 0.25,
+      BSSA_14, 0.25,
+      CB_14, 0.25,
+      CY_14, 0.25);
 
   /* 4.2 */
   static final class Wus2014_4p2 extends CombinedGmm {
@@ -232,12 +216,11 @@ class CombinedGmm implements GroundMotionModel {
     }
   }
 
-  private static final Map<Gmm, Double> WUS_2018 = ImmutableMap.<Gmm, Double> builder()
-      .put(ASK_14_BASIN, 0.25)
-      .put(BSSA_14_BASIN, 0.25)
-      .put(CB_14_BASIN, 0.25)
-      .put(CY_14_BASIN, 0.25)
-      .build();
+  private static final Map<Gmm, Double> WUS_2018 = Map.of(
+      ASK_14_BASIN, 0.25,
+      BSSA_14_BASIN, 0.25,
+      CB_14_BASIN, 0.25,
+      CY_14_BASIN, 0.25);
 
   /* No Idriss. */
   static final class Wus2018 extends CombinedGmm {

src/main/java/gov/usgs/earthquake/nshmp/gmm/GroundMotions.java

@@ -49,7 +49,6 @@ class GroundMotions {
         .mapToDouble(Branch::weight)
         .toArray();
     double mean = DoubleData.weightedSumLn(means, weights);
-    // double sigma = DoubleData.weightedSum(sigmas, weights);
     double sigma = Maths.srssWeighted(sigmas, weights);
     return GroundMotion.create(mean, sigma);
   }