inprogress

[jalview.git] / forester / java / src / org / forester / evoinference / matrix / distance / BasicSymmetricalDistanceMatrix.java

diff --git a/forester/java/src/org/forester/evoinference/matrix/distance/BasicSymmetricalDistanceMatrix.java b/forester/java/src/org/forester/evoinference/matrix/distance/BasicSymmetricalDistanceMatrix.java
index 616a91c..fdf2ec4 100644 (file)
--- a/forester/java/src/org/forester/evoinference/matrix/distance/BasicSymmetricalDistanceMatrix.java
+++ b/forester/java/src/org/forester/evoinference/matrix/distance/BasicSymmetricalDistanceMatrix.java
@@ -110,6 +110,9 @@ public final class BasicSymmetricalDistanceMatrix implements DistanceMatrix {
 
     @Override
     public final void setValue( final int col, final int row, final double d ) {
+        if ( d < 0 ) {
+            throw new IllegalArgumentException( "negative distance value" );
+        }
         if ( ( col == row ) && ( d != 0.0 ) ) {
             throw new IllegalArgumentException( "attempt to set a non-zero value on the diagonal of a symmetrical distance matrix" );
         }