Vector subtraction

aicis · Jan 10, 2019 · dbf642b · dbf642b
1 parent d86aaf9
commit dbf642b
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Showing 3 changed files with 32 additions and 1 deletion.
diff --git a/core/src/main/java/dk/alexandra/fresco/lib/real/DefaultLinearAlgebra.java b/core/src/main/java/dk/alexandra/fresco/lib/real/DefaultLinearAlgebra.java
@@ -148,6 +148,18 @@ public DRes<Matrix<DRes<SReal>>> sub(DRes<Matrix<DRes<SReal>>> a, Matrix<BigDeci
     });
   }
 
+  @Override
+  public DRes<Vector<DRes<SReal>>> subVectors(DRes<Vector<DRes<SReal>>> a, DRes<Vector<DRes<SReal>>> b) {
+    return builder.par(par -> {
+      Vector<DRes<SReal>> result = new Vector<>();
+      for (int i=0; i<a.out().size(); i++) {
+        DRes<SReal> element = par.realNumeric().sub(a.out().get(i), b.out().get(i));
+        result.add(element);
+      }
+      return () -> result;
+    });
+  }
+
   @Override
   public DRes<Matrix<DRes<SReal>>> mult(DRes<Matrix<DRes<SReal>>> a, Matrix<BigDecimal> b) {
     return builder.seq(seq -> {

diff --git a/core/src/main/java/dk/alexandra/fresco/lib/real/RealLinearAlgebra.java b/core/src/main/java/dk/alexandra/fresco/lib/real/RealLinearAlgebra.java
@@ -57,7 +57,12 @@ public interface RealLinearAlgebra extends ComputationDirectory {
    * @return A deferred result computing a-b
    */
   DRes<Matrix<DRes<SReal>>> sub(DRes<Matrix<DRes<SReal>>> a, Matrix<BigDecimal> n);
-
+
+  /**
+   * Subtracts two secret vectors.
+   */
+  DRes<Vector<DRes<SReal>>> subVectors(DRes<Vector<DRes<SReal>>> a, DRes<Vector<DRes<SReal>>> b);
+
   /**
    * Multiplies two secret values and returns the result.
    *

diff --git a/core/src/test/java/dk/alexandra/fresco/lib/real/LinearAlgebraTest.java b/core/src/test/java/dk/alexandra/fresco/lib/real/LinearAlgebraTest.java
@@ -159,6 +159,20 @@ public void testMatrixSubtraction() {
     }
   }
 
+  @Test
+  public void testVectorSubtraction() {
+    Vector<BigDecimal> a = new Vector<>(asList(valueOf(1.0), valueOf(2.0)));
+    Vector<BigDecimal> b = new Vector<>(asList(valueOf(0.3), valueOf(0.4)));
+    List<BigDecimal> output = run(root-> {
+      DRes<Vector<DRes<SReal>>> closedA = root.realLinAlg().input(a, 1);
+      DRes<Vector<DRes<SReal>>> closedB = root.realLinAlg().input(b, 1);
+      DRes<Vector<DRes<SReal>>> closedResult = root.realLinAlg().subVectors(closedA, closedB);
+      DRes<Vector<DRes<BigDecimal>>> opened = root.realLinAlg().openVector(closedResult);
+      return () -> unwrap(opened);
+    });
+    assertEqual(output, asList(valueOf(0.7), valueOf(1.6)), 15);
+  }
+
   @Test
   public void testMatrixScale() {
     // define input and output