#! /usr/bin/env python

"""
Plot the t=0 density expectation value in Lieb-Liniger (n-hole wavepacket).

Setup:
- ensure matplotlib and numpy are installed in your python environment
- make this file executable (chmod +x plot_to.py)

Usage: ./plot_t0.py [rho file name]
"""


import math
import matplotlib.pyplot as plt
import numpy as np
import sys

filename = str(sys.argv[1])

x = np.loadtxt(filename.replace('.rhoxt','.x'), unpack=True)

rho = np.loadtxt(filename, usecols=(0), unpack=True)

plt.plot(x, rho, '.', markersize=4)

plt.xlabel('x')
plt.ylabel(r'$\rho(x, t=0)$')
plt.title('Density expectation value\n' + filename)

plt.savefig(filename.replace('.rhoxt', '.png'))

plt.show()