text: import matplotlib.pyplot as plt
  import pandas as pd
  import numpy as np
  
  import sys
  cmdargs = str(sys.argv)
  
  snpden = str(sys.argv[1])
  vcf_file= str(sys.argv[1])
  coverage = str(sys.argv[1])
  
  def SNPdensity(snpden):
      density_data =  np.array(pd.read_csv(snpden, sep='\t'))
      plt.bar(density_data[:,1],density_data[:,2],color='Red',align='edge',width=1)
      plt.xticks(np.arange(min(density_data[:,1]), max(density_data[:,1]), 10000))
      plt.xticks(rotation=90)
      plt.show()
  
  def SNPquality(vcf_file):
      vcf_data = np.array(pd.read_csv(vcf_file, sep='\t', comment='#'))
      plt.bar(vcf_data[:,0], vcf_data[:,6], color='Blue')
      plt.xticks(np.arange(min(vcf_data[:,1]), max(vcf_data[:,1])+1000, 10000))
      plt.show()
  
  def Coverage(coverage):
      density_data =  np.array(pd.read_csv(coverage, sep='\t'))
      plt.bar(density_data[:,1],density_data[:,2],color='Red',align='edge',width=1)
      #plt.xticks(np.arange(min(density_data[:,0]), max(density_data[:,1]), 10000))
      plt.xticks(rotation=90)
      plt.show()
  
  if (str(sys.argv[2])=="snpden"):
      SNPdensity(snpden)
  elif (str(sys.argv[2])=="quality"):
      SNPquality(vcf_file)
  elif (str(sys.argv[2])=="coverage"):
      Coverage(coverage)