[Proposal] Support 1D search space in CMA-ES

cmaes/_cma.py

@@ -87,7 +87,7 @@ def __init__(
         ), f"Abs of all elements of mean vector must be less than {_MEAN_MAX}"
 
         n_dim = len(mean)
-        assert n_dim > 1, "The dimension of mean must be larger than 1"
+        assert n_dim > 0, "The dimension of mean must be positive"
 
         if population_size is None:
             population_size = 4 + math.floor(3 * math.log(n_dim))  # (eq. 48)

tests/test_fuzzing.py

@@ -10,7 +10,7 @@ class TestFuzzing(unittest.TestCase):
         data=st.data(),
     )
     def test_cma_tell(self, data):
-        dim = data.draw(st.integers(min_value=2, max_value=100))
+        dim = data.draw(st.integers(min_value=1, max_value=100))
         mean = data.draw(npst.arrays(dtype=float, shape=dim))
         sigma = data.draw(st.floats(min_value=1e-16))
         n_iterations = data.draw(st.integers(min_value=1))