diff --git a/src/backscattering_analyzer/analyzer.py b/src/backscattering_analyzer/analyzer.py
index 1d7525c..5bdb7e6 100644
--- a/src/backscattering_analyzer/analyzer.py
+++ b/src/backscattering_analyzer/analyzer.py
@@ -15,6 +15,7 @@ from scipy.signal import welch as psd
 from scipy.interpolate import CubicSpline
 from scipy.fft import fft, ifft, fftfreq
 
+
 class Analyzer:
     """
     Utility class to study backscattering light in VIRGO
@@ -128,7 +129,7 @@ class Analyzer:
             ]
         )
         self.movement[1] -= mean(self.movement[1])
-        self.movement = self.movement[:,:-500000]
+        self.movement = self.movement[:, :-500000]
 
     def psd_signal(self, signal, fft_length=10):
         """
@@ -257,8 +258,10 @@ class Analyzer:
                 ]
             )
 
-            factor_n, coupling_n, factor_d, coupling_d = self.interpolate(
-                (factor_n, coupling_n, factor_d, coupling_d)
+            factor_n, coupling_n, factor_d, coupling_d = (
+                self.interpolate(
+                    (factor_n, coupling_n, factor_d, coupling_d)
+                )
             )
 
             frequencies = factor_n[0]
@@ -283,9 +286,9 @@ class Analyzer:
         """
         Cut higher frequencies than cutoff for a given temporal signal
         """
-        sample_spacing = signal[0,1] - signal[0,0]
-        freq_signal = fft(signal[1])
+        sample_spacing = signal[0, 1] - signal[0, 0]
+        freq_signal = array(fft(signal[1]))
         frequencies = fftfreq(signal[1].shape[0], sample_spacing)
         index_to_remove = where(abs(frequencies) > cutoff)
         freq_signal[index_to_remove] = 0
-        return array([signal[0], real(ifft(freq_signal))])
+        return array([signal[0], real(array(ifft(freq_signal)))])