Q: is it possible to specify a dtype for random numbers when I create them.
A: No it isn’t. randn accepts the shape only as randn(d0, d1, …, dn)
Simply try this:
x = np.random.randn(10, 10).astype('f')
Or define a new function like
np.random.randn2 = lambda *args, dtype=np.float64: np.random.randn(*args).astype(dtype)
x = np.random.randn2(10, 10, dtype="f")
If you have to use your code on the post, try this code instead
x = np.zeros((10, 10), dtype="f")
x[:] = np.random.randn(*x.shape)
This assigns the results of randn to the memory allocated by np.zeros