diff --git a/t_sne/returnCorrectSigma_sparse.m b/t_sne/returnCorrectSigma_sparse.m
index 4396c08..29fee51 100644
--- a/t_sne/returnCorrectSigma_sparse.m
+++ b/t_sne/returnCorrectSigma_sparse.m
@@ -30,7 +30,9 @@
     else
         test = true;
     end
-    
+    if isinf(sigma) || isnan(sigma)
+        error('Starting sigma is %0.02f, highGuess is %0.02f and lowGuess is %0.02f. This usually means there are zeros in wavelet amplitudes, could be present in trainingSet too.', sigma, highGuess, lowGuess)
+    end
     while test
         
         if P > perplexity
@@ -65,4 +67,4 @@
     
     
     
-    
\ No newline at end of file
+