test(transforms): add tests for Exp, Identity, Logistic and Softplus

tspooner · Mar 4, 2019 · 0d269a0 · 0d269a0
1 parent 5aa8c6b
commit 0d269a0
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Showing 4 changed files with 99 additions and 1 deletion.
diff --git a/src/transforms/exponential.rs b/src/transforms/exponential.rs
@@ -9,6 +9,33 @@ impl Transform<f64> for Exp {
     }
 
     fn grad(&self, x: f64) -> f64 {
-        x * self.transform(x)
+        self.transform(x)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use quickcheck::quickcheck;
+    use std::f64::consts::E;
+    use super::{Exp, Transform};
+
+    #[test]
+    fn test_f64() {
+        assert!((Exp.transform(0.0) - 1.0).abs() < 1e-7);
+        assert!((Exp.transform(1.0) - E).abs() < 1e-7);
+        assert!((Exp.transform(2.0) - E * E).abs() < 1e-7);
+
+        assert!((Exp.transform(0.0) - Exp.grad(0.0)).abs() < 1e-7);
+        assert!((Exp.transform(1.0) - Exp.grad(1.0)).abs() < 1e-7);
+        assert!((Exp.transform(2.0) - Exp.grad(2.0)).abs() < 1e-7);
+    }
+
+    #[test]
+    fn test_f64_positive() {
+        fn prop_positive(x: f64) -> bool {
+            Exp.transform(x).is_sign_positive()
+        }
+
+        quickcheck(prop_positive as fn(f64) -> bool);
     }
 }
diff --git a/src/transforms/identity.rs b/src/transforms/identity.rs
@@ -26,3 +26,19 @@ impl Transform<Vector<f64>> for Identity {
         x
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::{Identity, Transform};
+
+    #[test]
+    fn test_f64() {
+        assert_eq!(Identity.transform(0.0), 0.0);
+        assert_eq!(Identity.transform(1.0), 1.0);
+        assert_eq!(Identity.transform(2.0), 2.0);
+
+        assert_eq!(Identity.grad(0.0), 1.0);
+        assert_eq!(Identity.grad(1.0), 1.0);
+        assert_eq!(Identity.grad(2.0), 1.0);
+    }
+}
diff --git a/src/transforms/logistic.rs b/src/transforms/logistic.rs
@@ -15,3 +15,30 @@ impl Transform<f64> for Logistic {
         exp_x / exp_x_plus_1 / exp_x_plus_1
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use quickcheck::quickcheck;
+    use std::f64::consts::E;
+    use super::{Logistic, Transform};
+
+    #[test]
+    fn test_f64() {
+        assert!((Logistic.transform(0.0) - 0.5).abs() < 1e-7);
+        assert!((Logistic.transform(1.0) - 1.0 / (1.0 + 1.0 / E)).abs() < 1e-7);
+        assert!((Logistic.transform(2.0) - 1.0 / (1.0 + 1.0 / E / E)).abs() < 1e-7);
+
+        assert!((Logistic.grad(0.0) - 0.25).abs() < 1e-5);
+        assert!((Logistic.grad(1.0) - 0.196612).abs() < 1e-5);
+        assert!((Logistic.grad(2.0) - 0.104994).abs() < 1e-5);
+    }
+
+    #[test]
+    fn test_f64_positive() {
+        fn prop_positive(x: f64) -> bool {
+            Logistic.transform(x).is_sign_positive()
+        }
+
+        quickcheck(prop_positive as fn(f64) -> bool);
+    }
+}
diff --git a/src/transforms/softplus.rs b/src/transforms/softplus.rs
@@ -12,3 +12,31 @@ impl Transform<f64> for Softplus {
         Logistic.transform(x)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::transforms::Logistic;
+    use quickcheck::quickcheck;
+    use std::f64::consts::E;
+    use super::{Softplus, Transform};
+
+    #[test]
+    fn test_f64() {
+        assert!((Softplus.transform(0.0) - 0.693147).abs() < 1e-5);
+        assert!((Softplus.transform(1.0) - 1.31326).abs() < 1e-5);
+        assert!((Softplus.transform(2.0) - 2.12693).abs() < 1e-5);
+
+        assert!((Softplus.grad(0.0) - Logistic.transform(0.0)).abs() < 1e-7);
+        assert!((Softplus.grad(1.0) - Logistic.transform(1.0)).abs() < 1e-7);
+        assert!((Softplus.grad(2.0) - Logistic.transform(2.0)).abs() < 1e-7);
+    }
+
+    #[test]
+    fn test_f64_positive() {
+        fn prop_positive(x: f64) -> bool {
+            Softplus.transform(x).is_sign_positive()
+        }
+
+        quickcheck(prop_positive as fn(f64) -> bool);
+    }
+}