Sanskrit Text: “Arjuna uvacha : senayor ubhayor madhye ratham sthapaya me acchutha”

Meaning: Arjuna requests Lord Krishna to drive his chariot into center of the two armies

Senayo: – Of the armies  – referring to the armies of Pandavas and Kauravas
Ubhayo – of both
Madhye – in the middle
Ratham – chariot
Sthapaya – stop
Me – My
Acchutha – the infallible

Interpretation:
With no intention of fighting against his own kins, Arjuna requests his Sarathi to take him into the center of two armies. But, the question here is why he wants to move into the center of the army?

May be he wants to be a spectator and see what is going on against Pandavas or he is so curious to see the kins and relatives who turned against them.

In this world, we come across the same situation many times, when we have to make a decision and we are so confused on which side we should fall. Only way we can get clarity on situation is by standing in the middle and weighing with the pros and cons of the situation. May be thats what Arjuna is trying to do.

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Learning L shaped OLL

Posted: July 24, 2017 in Uncategorized

There are 6 L shaped OLLs . In that first two can be easily memorized as one is mirror case of another . 

For the faster recognition I always write oll algorithm in notebook with a 2D notation.

First case is pretty easy to recognize. The hyphen in the outer layer denotes the yellow color . And “T” is RUR’U’.

Second case is easy to execute . But for faster recognition it would be easy to memorize it as third diagram. 

Double pawn in Ruy Lopez

Posted: July 24, 2017 in Uncategorized

Learning of the day :

This is the tactics that I learnt today to eliminate double pawn position while playing as black against Spanish Opening( screenshot given below)

img_0196
We need to play the move Nge7(knight e7) after white plays bishop b5.

img_0192
If white decides to capture the knight ,we can win back using the other knight. But , what if white doesnt trade and decides to castle ? By moving knight to e7 we blocked our dark square Bishop and king couldn’t castle.

We can play the move a6 which will threaten white bishop to move back. Now bishop moves back to A4. black plays b5 to put more pressure. White bishop settles in the square B3

img_0193
As the threat against the knight is eliminated, we can move Knight g6. However , black needs to keep in mind that white is eying on the f7 pawn.

img_0194
Now black can think about moving his dark square bishop and castle on kings side. And then place light squared bishop to b7.

img_0195
Played couple of games today with this position and felt comfortable than having double pawn .

Good luck !!!

Many of us would have encountered this situation where we need to run some script which takes hours together to complete.

And most of the time the shell goes inactive and it becomes really hard to track what has happened.

One simple solution for that is to run the script in background.\

For example:

./run_my_script.sh &

Oh.. But where are my logs.. Yes, its difficult for us to track what has happened, unless we redirect our output to some specific file .

Anyhow, we have a posix command in linux which can do this stuff. Its nohub.

Checkout the wikipedia link for it here

https://en.wikipedia.org/wiki/Nohup

all you need is to add nohup parameter before your script

nohup run_my_script.sh

Even if the shell goes down, doesnt matter.. We will have the process running in the background. And we can track the logs from nohub.out file . This file will be autocreated in the directory where we ran the script.

For installing python releated packages we need to use pip. Hence installing pip in our server is our first task.

the package name for pip is “python-pip”. Hence the straight forward approach to install pip would be

apt-get install python-pip

But, if the source list is not updated properly , we will end up with older version of pip (in my case i got 1.5.3 however, 8.1.1 is the latest one). Hence to avoid this issue , we need to follow the approach given in wikipedia

i.e  to download the package from internet via this url . Hence we use the curl command

curl https://bootstrap.pypa.io/get-pip.py

Once get-pip.py gets downloaded. run the python file to install pip

python get-pip.py

Even beyond this, if we need to install pip package without internet .

Download the source from https://pypi.python.org/pypi/pip

wget https://pypi.python.org/pypi?:action=show_md5&digest=6b86f11841e89c8241d689956ba99ed7

extract the folder

tar -xvzf pip-8.1.1.tar.gz

Move inside the folder and install it

cd pip-8.1.1; python setup.py install

Square Root Algorithm

Posted: March 17, 2016 in Uncategorized

There are N number of ways to compute square root of a number

we can use the existing library (math) in python to compute the square root

However, there is a constrain in number of decimal digits . Hence, we need an algorithm which can compute a square root and provide n decimal digits .

The following algorithm uses Digit by digit calculation from this wikipedia link

Square Root Computation Algorithms

I have created a python script which will compute square root of 2 with 100 decimal digits .

And i verified the digits from this link

First 100 Digits for SQRT of 2 – Verification

The algorithm is not optimized. However, it gives me the result quickly for first 100 digits

For multiple irrational number , populate the irr list (by default contains 2)

To control number of digits after decimal change decimal variable (by default set to 100)

<br data-mce-bogus="1">
import time
import math

starttime = time.time()

global flag, start, end, decimal
flag = True
start = 0
end = 1
decimal = 100


def main():

answer = 0
irr = [2]

# for each irrational number
for num in irr:

# Step - 1 : Converting number to string and appending 200 zeros
str_num = str(num)
for i in range(0, 210):
str_num = str_num + "0"

# Step - 2: Setting Flag : if lenght of the number is odd we need to take one digit or else two digits
if len(str_num) % 2 != 0:
flag = True
else:
flag = False

start = 0
end = 0
ap_new_dig = 0

# Step - 3: Logic to take one or 2 digits
if flag:
start = 0
end = 1

else:
start = 0
end = 2

temp_num = str_num[start:end]
temp_int_num = int(temp_num)

# Step - 4 : Calculate the initial quotiend and remainder

quo = int(math.sqrt(temp_int_num))
rem = temp_int_num - int(quo ** 2)

# Step - 5 : Here is the main logic to iterate the steps
counter = 0
while counter < decimal - 1 :

# Step - 6 : Bring down the digits
if flag:
start = start + 1
end = start + 2
flag = False
else:
start = start + 2
end = start + 2
new_dig = str_num[start:end]

# Step -7 : Add the digits with previous remainder
ap_new_dig = str(rem) + new_dig

# Step - 8 : Compute a number less than max ap_new_digit
double_num = quo * 2
max_val = 0
t = 0
for i in range(1, 10):
if int( str(double_num) + str(i) ) * i <= int(ap_new_dig):
t = int( str(double_num) + str(i) ) * i
max_val = i
else:
break

# Step - 9 : Find new quotient and remainder
quo = int ( str(quo) + str(max_val) )
rem = int(ap_new_dig) - t

counter = counter + 1

# Final Quotient will be the answer
print "Square Root of N is" , quo



main()

print "Time taken ", time.time() - starttime

Excecution:
 

>>>
Square Root of N is 1414213562373095048801688724209698078569671875376948073176679737990732478462107038850387534327641572
Time taken  0.0269999504089

 

 

I believe Bhagavad Gita is one of the best text where we can enjoy the essence of Story, Situation, Interpretation, Divinity and knowledge for life.

When we re-iterate the verses in our mind, every time a new interpretation for the verse pops up. The same happened today and hence i am writing this.

I am not writing something new. I heard these from different sources and all i am doing it to wrap it into a single text. Here you go.

Chapter -1 , First sloka –

http://www.bhagavad-gita.org/Gita/verse-01-01.html

The verse explains about the conversation between Dhritarashtra and Sanjaya where Dhritarashtra is asking about the current situation prevailing in the battle field.

  1. The first word describing about the Battle field – kurukshetra hints us the result. Dharma Kshetre – The land of righteousness. Author picked the right word in the situation, which clearly insights the victory of Pandavas over Kauravas. Author could have used any adjective about bravery , beauty or situation about the battle field , however, Righteousness was the right pick.
  2. Why does the author picks Dhritarashtra to be the first person to speak in bhagavad gita ? May be, those who are weak in mind and having evil thoughts will have very less things to be spoken. And so, the author picked him to be the first.
  3.  Evenhough Dhritarashtra is aware about the present scenario, his weak minded intuition triggers him to ask about the events happening in Kurukshetra. When two powerful teams are in battle, there will always be a win and lose. His low confidence about his team’s status triggers him to ask , “what they are doing in the battle field” – whole intention behind the statement was to know – “who is winning the war”.
  4.  He could have mentioned the team names to be Kauravas and Pandavas . But, he utters “My sons and Pandu’s sons ” which clearly establishes the difference he had in his mind for pandu and his team. Eventhough Pandu is his own brother
  5. And the whole verse not only explains about the battle field of Kurukshetra, it signifies about our own mind , where there is always a fight between good and an evil. We need to be aware that we may have less number of good qualities in our mind, we should never allow them to be taken over by evil .

 

     After all life is nothing but the war between a good and an evil.