[Python] Handle removal of numpy.trapz

Numpy 2.4.0 will remove trapz. To maintain compatibility with Numpy 1.x for now,
we need to dynamically select the correct function.

samples/python/onedim/diffusion_flame_continuation.py

@@ -26,6 +26,10 @@ logger = logging.getLogger(__name__)
 logger.setLevel(logging.INFO)
 logging.basicConfig(stream=sys.stdout)
 
+# Workaround to support both Numpy 1.x and 2.4.0+
+# TODO: Replace when dropping Numpy 1.x support
+trapezoid = getattr(np, "trapezoid", None) or np.trapz
+
 # %%
 # Flame Initialization
 # --------------------
@@ -162,7 +166,7 @@ for i in range(n_max):
     data.append({
         'T_max': max(f.T),
         'strain_rate': strain_rate,
-        'heat_release_rate': np.trapz(f.heat_release_rate, f.grid),
+        'heat_release_rate': trapezoid(f.heat_release_rate, f.grid),
         'n_points': len(f.grid),
         'flame_width': width,
         'Tc_increment': temperature_increment,

samples/python/onedim/premixed_counterflow_twin_flame.py

@@ -25,6 +25,9 @@ from pathlib import Path
 import numpy as np
 import cantera as ct
 
+# Workaround to support both Numpy 1.x and 2.4.0+
+# TODO: Replace when dropping Numpy 1.x support
+trapezoid = getattr(np, "trapezoid", None) or np.trapz
 
 # Differentiation function for data that has variable grid spacing Used here to
 # compute normal strain-rate
@@ -63,7 +66,7 @@ def compute_consumption_speed(opposed_flame):
 
     integrand = opposed_flame.heat_release_rate / opposed_flame.cp
 
-    total_heat_release = np.trapz(integrand, opposed_flame.grid)
+    total_heat_release = trapezoid(integrand, opposed_flame.grid)
     Sc = total_heat_release / (Tb - Tu) / rho_u
 
     return Sc

samples/python/reactors/ic_engine.py

@@ -17,6 +17,10 @@ import numpy as np
 
 import matplotlib.pyplot as plt
 
+# Workaround to support both Numpy 1.x and 2.4.0+
+# TODO: Replace when dropping Numpy 1.x support
+trapezoid = getattr(np, "trapezoid", None) or np.trapz
+
 #########################################################################
 # Input Parameters
 #########################################################################
@@ -252,13 +256,13 @@ plt.show()
 ######################################################################
 
 # heat release
-Q = np.trapz(states.heat_release_rate * states.V, t)
+Q = trapezoid(states.heat_release_rate * states.V, t)
 output_str = '{:45s}{:>4.1f} {}'
 print(output_str.format('Heat release rate per cylinder (estimate):',
                         Q / t[-1] / 1000., 'kW'))
 
 # expansion power
-W = np.trapz(states.dWv_dt, t)
+W = trapezoid(states.dWv_dt, t)
 print(output_str.format('Expansion power per cylinder (estimate):',
                         W / t[-1] / 1000., 'kW'))
 
@@ -268,6 +272,6 @@ print(output_str.format('Efficiency (estimate):', eta * 100., '%'))
 
 # CO emissions
 MW = states.mean_molecular_weight
-CO_emission = np.trapz(MW * states.mdot_out * states('CO').X[:, 0], t)
-CO_emission /= np.trapz(MW * states.mdot_out, t)
+CO_emission = trapezoid(MW * states.mdot_out * states('CO').X[:, 0], t)
+CO_emission /= trapezoid(MW * states.mdot_out, t)
 print(output_str.format('CO emission (estimate):', CO_emission * 1.e6, 'ppm'))