diff --git a/latex/thesis/common.tex b/latex/thesis/common.tex
index 762b755..91e89b0 100644
--- a/latex/thesis/common.tex
+++ b/latex/thesis/common.tex
@@ -65,6 +65,15 @@
                 \def\pgfmathresult{inf}
             \fi
         }
+    },
+    discard if lt/.style 2 args={
+        x filter/.append code={
+            \edef\tempa{\thisrow{#1}}
+            \edef\tempb{#2}
+            \ifdim\tempa pt < \tempb pt
+                \def\pgfmathresult{inf}
+            \fi
+        }
     }
 }