1 files changed, 48 insertions, 0 deletions
diff --git a/buch/papers/laguerre/scripts/integrand.py b/buch/papers/laguerre/scripts/integrand.py
new file mode 100644
index 0000000..43fc1bf
--- /dev/null
+++ b/buch/papers/laguerre/scripts/integrand.py
@@ -0,0 +1,48 @@
+#!/usr/bin/env python3
+# -*- coding:utf-8 -*-
+"""Plot for integrand of gamma function with shifting terms."""
+
+import os
+from pathlib import Path
+
+import matplotlib.pyplot as plt
+import numpy as np
+
+EPSILON = 1e-12
+xlims = np.array([-3, 3])
+
+root = str(Path(__file__).parent)
+img_path = f"{root}/../images"
+os.makedirs(img_path, exist_ok=True)
+
+t = np.logspace(*xlims, 1001)[:, None]
+
+z = np.array([-4.5, -2, -1, -0.5, 0.0, 0.5, 1, 2, 4.5])
+r = t ** z
+
+fig, ax = plt.subplots(num=1, clear=True, constrained_layout=True, figsize=(6, 4))
+ax.semilogx(t, r)
+ax.set_xlim(*(10.0 ** xlims))
+ax.set_ylim(1e-3, 40)
+ax.set_xlabel(r"$t$")
+ax.set_ylabel(r"$t^z$")
+ax.grid(1, "both")
+labels = [f"$z={zi:.1f}$" for zi in np.squeeze(z)]
+ax.legend(labels, ncol=2, loc="upper left")
+fig.savefig(f"{img_path}/integrands.pgf")
+
+z2 = np.array([-1, -0.5, 0.0, 0.5, 1, 2, 3, 4, 4.5])
+r2 = t**z2 * np.exp(-t)
+
+fig2, ax2 = plt.subplots(num=2, clear=True, constrained_layout=True, figsize=(6, 4))
+ax2.semilogx(t, r2)
+# ax2.plot(t,np.exp(-t))
+ax2.set_xlim(10**(-2), 20)
+ax2.set_ylim(1e-3, 10)
+ax2.set_xlabel(r"$t$")
+ax2.set_ylabel(r"$t^z e^{-t}$")
+ax2.grid(1, "both")
+labels = [f"$z={zi:.1f}$" for zi in np.squeeze(z2)]
+ax2.legend(labels, ncol=2, loc="upper left")
+fig2.savefig(f"{img_path}/integrands_exp.pgf")
+plt.show()