Question: I am having a trouble getting formula for bootstrap affix layout. [Please check image for layout](http://imgur.com/a/wfZyM).

All green sections height must be dynamic. Affix should move only in white region.

For top offset I use sections A height.
What formula should I use for bottom offset?

CSS side works fine (I guess).

Answer: 
I have started to learn **Matplotlib** and **Numpy** recently and found your question quite interesting. 

So, I spend time to create a combined graph of grouped-bar chart and line chart relevant to that grouped-bar chart. 

**Result**:
[![enter image description here](https://i.stack.imgur.com/pkPOg.png)](https://i.stack.imgur.com/pkPOg.png)

**Code:**

```
import numpy as np
import matplotlib.pyplot as plt

ind = np.arange(5)
avg_bar1 = (81191,79318,57965,60557,14793)
avg_bar2 = (26826,26615,31364,31088,55472)
avg_bar3 = (36232,38038,38615,39014,40812)
avg_bar4 = (26115,25879,25887,28326,27988)

rects1 = plt.bar(ind, avg_bar1, 0.15, color='#ff0000',label='bar1')
rects2 = plt.bar(ind + 0.15, avg_bar2, 0.15, color='#00ff00', label='bar2')
rects3 = plt.bar(ind + 0.30, avg_bar3, 0.15, color='#0000ff', label='bar3')
rects4 = plt.bar(ind + 0.45, avg_bar4, 0.15, color='#000000', label='bar4')

high_point_x = []
high_point_y = []    
for i in range(0,5):
    single_bar_group={rects1[i].get_height():rects1[i].get_x() + rects1[i].get_width()/2.0,
                      rects2[i].get_height():rects2[i].get_x() + rects2[i].get_width()/2.0,
                      rects3[i].get_height():rects3[i].get_x() + rects3[i].get_width()/2.0,
                      rects4[i].get_height():rects4[i].get_x() + rects4[i].get_width()/2.0}

    height_list = list(single_bar_group.keys())
    height_list.sort(reverse=True)
    for single_height in height_list:
        high_point_y.append(single_height)
        high_point_x.append(single_bar_group[single_height])
        break

trend_line = plt.plot(high_point_x,high_point_y,marker='o', color='#5b74a8', label='Trend Line')

plt.xlabel('Distributions')
plt.ylabel('ms')
plt.xticks(ind+0.15, ('50/50', '60/40', '70/30', '80/20', '90/10'))
plt.legend()
plt.show()

```
Thank you @arsho for your input. I have made it a little more compact. It fixed also the error on the last group of bars in your code. See comments in code. Hope this helps.

For those like me who are new to matplotlib: we can simple plot a line to the subplot, no matter if it already contains bars.

```
import numpy as np
import matplotlib.pyplot as plt

# fig, is the whole thing; ax1 is a subplot in the figure, 
# so we reference it to plot bars and lines there
fig, ax1 = plt.subplots()

ind = np.arange(3)
width = 0.15

# per dimension
colors = ['#00ff00', '#0000ff', '#ff00ff']
markers = ['x','o','v']
xticklabels = ['50/50', '60/40', '70/30']

# 
group1 = [12,6,5]
group2 = [6,8,12]
group3 = [2,4,9]

#
all_groups = [ group1, group2, group3 ]

# plot each group of bars; loop-variable bar_values contains values for bars
for i, bar_values in enumerate( all_groups ):

  # compute position for each bar
  bar_position = width*i
  ax1.bar( ind + bar_position, bar_values, width, color=colors[i] )

# plot line for each group of bars; loop-variable y_values contains values for lines
for i, y_values in enumerate( all_groups ):

  # moves the beginning of a line to the middle of the bar
  additional_space = (width*i) + (width/2);
  # x_values contains list indices plus additional space
  x_values = [ x + additional_space for x,_ in enumerate( y_values ) ]

  # simply plot the values in y_values
  ax1.plot( x_values, y_values, marker=markers[i], color=colors[i] )

plt.setp([ax1], xticks=ind + width, xticklabels=xticklabels)

plt.tight_layout()
plt.show()

```