Fix NumPy 2 compatibility

requirements.txt

@@ -1,4 +1,4 @@
-numpy==1.24.3
+numpy
 scipy
 scikit-learn
 matplotlib

ssmlearnpy/reduced_dynamics/shift_or_differentiate.py

@@ -1,6 +1,5 @@
 import logging
 import numpy as np
-#from ssmlearnpy.utils.finite_time_differences import finite_time_differences
 from findiff import FinDiff
 
 #logger = logging.getlogger("shift_or_differentiate")
@@ -20,8 +19,8 @@ def shift_or_differentiate(x, t, type, accuracy = 4):
         #logger.info("Differentiate data for continuous time dynamical system")
         X, y = [], []
         for i_traj in range(len(x)):
-           # create finite difference object    
-            fd = FinDiff(1, t[i_traj][1] - t[i_traj][0], 1, acc = accuracy) # first order differential with given accuracy
+            # create finite difference object    
+            fd = FinDiff(1, float(t[i_traj][1] - t[i_traj][0]), 1, acc=accuracy) # first order differential with given accuracy
             dx_dt_traj = fd(np.array(x[i_traj])) # findiff differentiates along axis 0.
             X.append(x[i_traj])
             y.append( dx_dt_traj)

ssmlearnpy/utils/ridge.py

@@ -2,7 +2,6 @@
 
 
 import numpy as np
-from numpy.lib.arraysetops import isin
 from sklearn.preprocessing import StandardScaler
 from sklearn.preprocessing import PolynomialFeatures, FunctionTransformer
 from sklearn.gaussian_process.kernels import Kernel