🔒 RuntimeWarning: overflow encountered in scalar multiply

[eternal bridge]

complete newbie when it comes to python, no idea how to fix it

[fervent roost]

@eternal bridge

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[eternal bridge]

  alpha=0.67
  beta=67*10^(-5)
  gamma=-1
  delta=-5*10^(-4) 
  def LV(t,MT:np.ndarray):
   x=MT[0]
   y=MT[1]
   dx=x*(alpha-beta*y)
   dy=y*(gamma-delta*x)
   R=[dx,dy]
   return (R)```

the relevant code

  dx=x*(alpha-beta*y)
<ipython-input-61-d661bbf27121>:13: RuntimeWarning: overflow encountered in scalar multiply
  dy=y*(gamma-delta*x)```

and the warning

[indigo lintel]

What is the output of print(MT.dtype)?

[eternal bridge]

AttributeError: 'list' object has no attribute 'dtype'

  import scipy
  alpha=0.67
  beta=67*10^(-5)
  gamma=-1
  delta=-5*10^(-4) 
  t=np.arange(0.,10.+dt,dt)
  def LV(t,MT:np.ndarray):
   x=MT[0]
   y=MT[1]
   dx=x*(alpha-beta*y)
   dy=y*(gamma-delta*x)
   R=[dx,dy]
   alpha=0.67
   beta=67*10^(-5)
   gamma=-1
   delta=-5*10^(-4) 
   print(MT.dtype)
   return (R)
  a=0
  b=1
  c=7
  No0=1000+100*a-50*b
  Ni0=300+30*a-15*c
  N0=np.array([No0,Ni0])
  RKT=scipy.integrate.solve_ivp(LV ,t_span=(0,10), y0=N0, method='RK45',t_eval=t)
  nomax=max(RKT.y[0])
  nomin=min(RKT.y[0])
  nimax=max(RKT.y[1])
  nimin=min(RKT.y[1])
  return np.array([nomax,nomin,nimax,nimin])``` also heres the full thing

[indigo lintel]

That's not good, since that means while you have MT:np.ndarray, MT is actually a list, so your types are wrong. Aside from that, what is print(x.dtype, y.dtype)?

[eternal bridge]

ints

[indigo lintel]

Ok, but what int more specifically?

[eternal bridge]

AttributeError: 'int' object has no attribute 'dtype'

[eternal bridge]

actually nvm i got it, i think it was showing the warning cause of the "MT:np.ndarray". ran without it, all 3 are float64 + no warning

!solved

[fervent roost]

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