title: RuntimeWarning: overflow encountered in double_scalars
body: <p>I get the error RuntimeWarning: overflow encountered in double_scalars and I am not sure what it means (internet research did not help) and what double_scalars are.</p>
  
  <p>I am not dividing by zero, so could it be that the warning/error arrises as I have too many decimal points or because the numbers are to large?
  I do get inf for a lot of them.</p>
  
  <p>Is there a way I can get around this error?</p>
  
  <p>This part ist just importing and defining variable:</p>
  
  <pre><code>
  ## IMPORT PACKAGES
  import numpy as np
  import math
  import matplotlib.pyplot as plt
  
  
  ## DEFINITION AND VALUE OF PARAMETERS
  A = 10**-16       
  rho = 910                              
  g = 9.81                                           
  a = 1                               
  n = 3
  fact = A * ((rho * g)**n) 
  t_end = 10 
  dt = 1 
  dx = 100 
  L = 300000
  b = 0
  H_0 = 1000 
  </code></pre>
  
  <p>This part should be ok</p>
  
  <pre><code>
  ## Solve equation numerically
  
  # initialization
  xint = np.arange(-L, L+dx, dx) 
  H_old = []
  
  for xind in range(len(xint)):
      x = xint[xind]
      H_old.append(H_0 * (1 - abs(x)/L))
  H_new = H_old   
  result = [H_old]
  print(len(xint),len(H_old))
  </code></pre>
  
  <p>I think that this part causes troubles</p>
  
  <pre><code># Loops through the time-span
  for t in range(0, t_end+dt, dt):
      print(t,min(H_old),max(H_old)) 
  
      # Loops through the x-range
      for xind in range(1,len(xint)):
          x = xint[xind]
          if x &lt; L and x &gt; -L:
              dH1 = (H_old[xind]-H_old[xind-1])/dx
              H1 = H_old[xind]
              dH2 = (H_old[xind+1]-H_old[xind])/dx
              H2 = H_old[xind+1]
  
              v1 = - (2/4)/(n+1) * fact * ((abs(dH1))**(n-1)) * dH1 * H1**4 
              v2 = - (2/4)/(n+1) * fact * ((abs(dH2))**(n-1)) * dH2 * H2**4
              dH_dt = - (H2*v2-H1*v1)/dx + a 
              H_new[xind] = H_old[xind] + dt * dH_dt 
  
          else:                           
              H_new[xind] = 0.0
  
      H_old = H_new   
      result.append(H_old)
  
  
  
  
  Thanks
  </code></pre>