Fix positive_definite_matrices to actually use the dtype

Author: asmeurer

array_api_tests/hypothesis_helpers.py

@@ -127,15 +127,16 @@ def tuples(elements, *, min_size=0, max_size=None, unique_by=None, unique=False)
     .filter(lambda S: all(prod(i for i in shape if i) < MAX_ARRAY_SIZE for shape in S))
 
 @composite
-def positive_definite_matrices(draw, dtype=xps.floating_dtypes()):
+def positive_definite_matrices(draw, dtypes=xps.floating_dtypes()):
     # For now just generate stacks of identity matrices
     # TODO: Generate arbitrary positive definite matrices, for instance, by
     # using something like
     # https://github.com/scikit-learn/scikit-learn/blob/844b4be24/sklearn/datasets/_samples_generator.py#L1351.
     n = draw(integers(0))
     shape = draw(shapes) + (n, n)
     assume(prod(i for i in shape if i) < MAX_ARRAY_SIZE)
-    return broadcast_to(eye(n), shape)
+    dtype = draw(dtypes)
+    return broadcast_to(eye(n, dtype=dtype), shape)
 
 @composite
 def two_broadcastable_shapes(draw):