plot_correlations

import numpy as np
import matplotlib.pyplot as plt
import csv


# ----- Load xi and rho -----
xi_data = {}
rho_data = {}


with open("ising_1D_data.csv") as f:
   reader = csv.reader(f)
   next(reader)
   for row in reader:
       T = float(row[0])
       rho_data[T] = float(row[1])
       xi_data[T] = float(row[2])


# ----- Plot ξ vs T -----
plt.figure(figsize=(8,6))
plt.plot(list(xi_data.keys()), list(xi_data.values()), 'o-', color='red')
plt.xlabel("Temperature T")
plt.ylabel("Correlation Length ξ")
plt.title("1D Ising Correlation Length vs Temperature")
plt.grid(True)
plt.savefig("ising_1D_xi_vs_T.png", dpi=150)


# ----- Plot ρ vs T -----
plt.figure(figsize=(8,6))
plt.plot(list(rho_data.keys()), list(rho_data.values()), 'o-', color='green')
plt.xlabel("Temperature T")
plt.ylabel("Domain Wall Density ρ")
plt.title("1D Ising Domain Wall Density vs Temperature")
plt.grid(True)
plt.savefig("ising_1D_rho_vs_T.png", dpi=150)


plt.close("all")
print("Plots generated.")