text: user7426: I model the following events: a rod-shaped cell with center $x$ grows symmetrically until it reaches a maximum length/age, it divides into two identical cells, and the process continues. At division, the direction angle $\varphi$ of the daughter cells changes randomly. 
  So, the growth rate is $l=\frac{l_{max}}{2}+\frac{a}{a_{max}}\frac{l_{max}}{2}$
  Is there any way of naively visualizing this? I found different cell modellers on GitHub but they were very complicated biologically speaking. I have some basic Python knowledge, but I have never done simulations. 
  
  user2108: I would recommend looking into Python's plotting utilities, for example here.
  I would recommend specifically looking at the examples that plot mathematical functions.
  The basic idea is that you create a function that computes your equation based on the different parameters as inputs ($a, a_{max}, l_{max}$) and then you can plug in a range of values for each parameter and plot e.g. with $a_{max}$ on the x axis, then different lines showing a range of values for $l_{max}$, or whatever makes sense for you.
  e.g. 
  import numpy as np
  import matplotlib.pyplot as plt
  
  def fn(a, amax, lmax):
    return lmax/2 + (a/amax) * (lmax/2)
  
  plt.figure()
  amax = np.arange(0.01, 1, .01)
  plt.plot(amax, fn(.005, amax, .1), "ro") ## red points
  plt.plot(amax, fn(.005, amax, .2), "go") ## green point
  plt.show()
  
  I have no idea if these parameter ranges are meaningful for you, you will have to figure that out for yourself. 
  
  
original_text: 7426: <p>I model the following events: a rod-shaped cell with center <span class="math-container">$x$</span> grows symmetrically until it reaches a maximum length/age, it divides into two identical cells, and the process continues. At division, the direction angle <span class="math-container">$\varphi$</span> of the daughter cells changes randomly. </p>
  
  <p>So, the growth rate is <span class="math-container">$l=\frac{l_{max}}{2}+\frac{a}{a_{max}}\frac{l_{max}}{2}$</span></p>
  
  <p>Is there any way of naively visualizing this? I found different cell modellers on GitHub but they were very complicated biologically speaking. I have some basic Python knowledge, but I have never done simulations. </p>
   2108: <p>I would recommend looking into Python's plotting utilities, for example <a href="https://matplotlib.org/tutorials/introductory/pyplot.html" rel="nofollow noreferrer">here</a>.</p>
  
  <p>I would recommend specifically looking at the examples that plot mathematical functions.</p>
  
  <p>The basic idea is that you create a function that computes your equation based on the different parameters as inputs (<span class="math-container">$a, a_{max}, l_{max}$</span>) and then you can plug in a range of values for each parameter and plot e.g. with <span class="math-container">$a_{max}$</span> on the x axis, then different lines showing a range of values for <span class="math-container">$l_{max}$</span>, or whatever makes sense for you.</p>
  
  <p>e.g. </p>
  
  <pre><code>import numpy as np
  import matplotlib.pyplot as plt
  
  def fn(a, amax, lmax):
    return lmax/2 + (a/amax) * (lmax/2)
  
  plt.figure()
  amax = np.arange(0.01, 1, .01)
  plt.plot(amax, fn(.005, amax, .1), "ro") ## red points
  plt.plot(amax, fn(.005, amax, .2), "go") ## green point
  plt.show()
  </code></pre>
  
  <p>I have no idea if these parameter ranges are meaningful for you, you will have to figure that out for yourself. </p>
  
  <p><a href="https://i.stack.imgur.com/Nc6FU.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Nc6FU.png" alt="enter image description here"></a></p>
  