Fix experiment

Author: tgross35

src/math/generic/ceil.rs

@@ -25,15 +25,15 @@ pub fn ceil<F: Float>(x: F) -> F {
 
         // Otherwise, raise an inexact exception.
         force_eval!(x + F::MAX);
-        if x.is_sign_negative() {
+        if x.is_sign_positive() {
             ix += m;
         }
         ix &= !m;
     } else {
         // No integer part, raise an inexact exception since truncation will happen.
         force_eval!(x + F::MAX);
 
-        if x.is_sign_positive() {
+        if x.is_sign_negative() {
             return F::NEG_ZERO;
         } else if ix << 1 != zero {
             return F::ONE;