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Python Functions

The following tutorial is an introduction to built-in Python functions such as average, standard deviation, maximum, minimum, and conditional counting.

Python Source Code

 import random
 y = [random.random()*100.0 for i in range(10)]
 print("Print y")
 print(y)

 print("Sorted List")
 for i in range(len(y)):
     print("%.2f" % y[i])

 def avg(x):
     return sum(x) / len(x)

 print("Avg: " + str(avg(y)))
 print("Max: " + str(max(y)))
 print("Min: " + str(min(y)))
 z = sum(1 if i<50.0 else 0 for i in y)
 print("Number Below 50: " + str(z))

 # another method with NumPy
 import numpy as np
 print(np.mean(y))
 print(np.average(y))
 print(np.std(y))
 print(np.median(y))

Data statistics can also be completed with a spreadsheet program like Microsoft Excel and MATLAB where the data sets are arrays or matrices instead of tables in a spreadsheet. Click on the appropriate link for additional information and source code.

Non-Ideal Gas Function Example

Source Code

 def P_RK_IG(V, T, do_ideal_gas=False):
    R = 0.0821  # L-atm/K
    Pc = 37.2   # atm
    Tc = 132.5  # K

    a = 0.427 * pow(R,2) * pow(Tc,2.5) / Pc
    b = 0.0866 * R * Tc / Pc

    # Compute in atm
    P_ig = R * T / V
    P_rk = R * T / (V-b) - a/(V*(V+b)*pow(T,0.5))

    # Convert to Pascals
    if do_ideal_gas:
       return P_ig * 101325
    else:
       return P_rk * 101325

 for T in range(490,511,10):
    V = 4.0
    while V < 8:
       print("----- Temperature: " + str(T) + " K")
       print("P_ig: " + str(P_RK_IG(V,T,True)) + " Pa")
       print("P_rk: " + str(P_RK_IG(V,T)) + " Pa")
       V = V + 2.0

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