Short Break from Research

This is my little angel.

She is born in November 2013.

And she said, “Papa. Can you stop doing your research and play with me a while?”2013-11-16 14.01.28


Linux Mint Maya KDE – Hibernation Issue in Dell Vostro 3450

Hibernation is a must-have feature in a laptop. I can work on my programming, then hibernate the machine in 30 seconds, take a nap and resume the machine to the state before it hibernates in 30 seconds and continue my work — I can just continue my work from I stop seamlessly. However, the hibernation function seems to be missing in Linux Mint Maya (KDE) in my Dell Vostro 3450. The followings are the patches to overcome this issue.

The patches include:
1. Prepare the scripts to hibernate.
2. Make an hibernation icon in the start menu.
3. Solve the noisy fan issue (due to the hybrid card) after resume from hibernation.

Continue reading “Linux Mint Maya KDE – Hibernation Issue in Dell Vostro 3450”

Solving Simultaneous Equations with Python

I own a very old fashion scientific calculator and it can’t solve any simultaneous equations like those new calculators (not even 2×2!). The situation goes worst when I try to do my Circuit Theory tutorial, in which I need to solve many simultaneous equations. Can’t I just concentrate on forming the equations and let someone to solve them for me?

Well! Let the Python do it!

All you have to do is forming the proper equations. Then, fire up the following script. Key in the proper coefficients of each equation when Python asks.

Please feel free to copy and use it anywhere you like.


import numpy as np

print 'How many variables ?'
print '>> ',
total_variable = int(raw_input())

# User key in all the variable numbers

equation_list = []

for i in range(total_variable):
    print 'Please enter the coefficients of the #%d equation.' % (i+1)
    print 'For example: (1)*x0 + (2)*x1 = (3) ---> "1 2 3"'
    print '>> ',
    user_input = raw_input()
    user_token_str = user_input.split()
    assert (len(user_token_str)== (total_variable +1))
    user_token = [float(u) for u in user_token_str]

equation_arr = np.array(equation_list)

# A * X = Y
# Given A and Y, we need to find X.

Y_arr = equation_arr[:, -1:]
A_arr = equation_arr[:, :-1]

print 'Y_arr:' , Y_arr
print 'A_arr:' , A_arr

X_arr = np.linalg.solve(A_arr, Y_arr)

print 'Answer:'
for i, x in enumerate (X_arr):
    print 'x%d value: %f' % (i, x)