noise fix

src/scgenerator/noise.py

@@ -45,7 +45,7 @@ class NoiseMeasurement:
     def from_time_series(
         cls,
         signal: Sequence[float],
-        dt: float,
+        dt: float = 1.0,
         window: str | None = "Hann",
         num_segments: int = 1,
         force_no_dc: bool = True,

tests/test_noise.py

@@ -58,7 +58,7 @@ def test_time_and_back():
 def test_nyquist():
     """
     generating a time series and tranforming it back yields the same spectrum.
-    Using segements, the nyquist frequency at least is the same
+    Using segements, the nyquist frequency is exactly spread out over the frequency bin width
     """
     signal = np.cos(np.arange(1024) * np.pi)
 
@@ -66,7 +66,7 @@ def test_nyquist():
     n3 = sc.noise.NoiseMeasurement.from_time_series(signal, 1, None, 3)
     n15 = sc.noise.NoiseMeasurement.from_time_series(signal, 1, None, 15)
 
-    assert n1.psd[-1] == n3.psd[-1] == n15.psd[-1]
+    assert n1.psd[-1] == n3.psd[-1] * 2 == n15.psd[-1] * 8
 
 
 def test_sampling():