summary | Study of Everything

Black-Scholes Model

SungjaeMay 18, 2016May 18, 2016

The Black-Scholes Equation $latex \frac{\partial V}{\partial t}+\frac{1}{2}\sigma^2 S^2 \frac{\partial^2 V}{\partial S^2}+rS\frac{\partial V}{\partial S}-rV=0 &s=3$ $latex S$: the price of the stock $latex V=V(S,t)$: the price of a derivative(e.g., option) $latex K$: the strike price of the option $latex r$: the annualized risk-free interest rate $latex \sigma$: the standard deviation of the stock’s return $latex […]

Start to Develop C Programs Using Eclipse in Ubuntu

SungjaeMarch 19, 2016

Installation Open the terminal. Ctrl+Alt+t Update apt-get program

sudo apt-get update

1	sudo apt-get update

enter the user password Yes-type ‘y’- to all the questions while the installation. Install Java JDK

sudo apt-get install openjdk-6-jdk

1	sudo apt-get install openjdk-6-jdk

(You can change jdk version by switching 6 to the version you want.) Yes-type ‘y’- to all the questions while the installation. Install Eclipse

sudo apt-get install eclipse

1	sudo apt-get install eclipse

Yes-type ‘y’- to all […]

The Empty String, the Empty List, and Zero All Evaluate to False

SungjaeMarch 3, 2016March 3, 2016

The empty string, the empty list, the empty dictionary, the empty set, and zero all evaluate to False.

bool('') # the empty string
Out[1]: False

bool('a non-empty string') # a non-emepty string
Out[2]: True

bool(list()) # the empty list
Out[3]: False

bool(['a non-empty list']) # a non-empty list
Out[4]: True

bool(dict()) # the empty dictionary
Out[5]: False

bool({'key':'value'}) # a non-empty dictionary
Out[6]: True

bool(set()) # the empty set
Out[7]: False

bool({'a non-empty set'}) # a non-empty set
Out[8]: True

bool(0) # zero
Out[9]: False

bool(1) # a non-zero
Out[10]: True

bool('') # the empty string

Out[1]: False

bool('a non-empty string') # a non-emepty string

Out[2]: True

bool(list()) # the empty list

Out[3]: False

bool(['a non-empty list']) # a non-empty list

Out[4]: True

bool(dict()) # the empty dictionary

Out[5]: False

bool({'key':'value'}) # a non-empty dictionary

Out[6]: True

bool(set()) # the empty set

Out[7]: False

bool({'a non-empty set'}) # a non-empty set

Out[8]: True

bool(0) # zero

Out[9]: False

bool(1) # a non-zero

Out[10]: True

Conversion Between Str and Bytes

SungjaeMarch 2, 2016March 2, 2016

Diagram: Conversion Between Str and Bytes Conversion to String

def to_str(bytes_or_str):
    if isinstance(bytes_or_str, bytes):
        # bytes_or_str is bytes.
        value = bytes_or_str.decode('utf-8')
    else:
        # bytes_or_str is not bytes, but str.
        value = bytes_or_str
    return value

def to_str(bytes_or_str):

if isinstance(bytes_or_str, bytes):

# bytes_or_str is bytes.

value = bytes_or_str.decode('utf-8')

else:

# bytes_or_str is not bytes, but str.

value = bytes_or_str

return value

>>> bytes_ex = b'This is a string.'
>>> str_ex = 'This is a string'
>>> to_str(bytes_ex)
'This is a string'
>>> to_str(str_ex)
'This is a string'

>>> bytes_ex = b'This is a string.'

>>> str_ex = 'This is a string'

>>> to_str(bytes_ex)

'This is a string'

>>> to_str(str_ex)

'This is a string'

Conversion To Bytes

def to_bytes(bytes_or_str):
    if isinstance(bytes_or_str, str):
        # bytes_or_str is str.
        value = bytes_or_str.encode('utf-8')
    else:
        # bytes_or_str is not str, but bytes
        value = bytes_or_str
    return value

def to_bytes(bytes_or_str):

if isinstance(bytes_or_str, str):

# bytes_or_str is str.

value = bytes_or_str.encode('utf-8')

else:

# bytes_or_str is not str, but bytes

value = bytes_or_str

return value

>>> bytes_ex = b'This is a string.'
>>> str_ex = 'This is a string'
>>> to_bytes(bytes_ex)
b'This is a string'
>>> to_bytes(str_ex)
b'This is a string'

>>> bytes_ex = b'This is a string.'

>>> str_ex = 'This is a string'

>>> to_bytes(bytes_ex)

b'This is a string'

>>> to_bytes(str_ex)

b'This is a string'

Write a?File in Write Binary Mode (‘wb’)

with open('binary.txt', 'wb') as f:
    f.write(to_bytes(str_ex))

with open('bytes.txt', 'wb') as f:
    f.write(to_bytes(bytes_ex))

with open('binary.txt', 'wb') as f:

f.write(to_bytes(str_ex))

with open('bytes.txt', 'wb') as f:

f.write(to_bytes(bytes_ex))

Write a?File in Write Character?Mode (‘w’)

with open('str.txt', 'w') as f:
    f.write(to_str(str_ex))

with open('str.txt', 'w') as f:
    f.write(to_str(bytes_ex))

with open('str.txt', 'w') as f:

f.write(to_str(str_ex))

with open('str.txt', 'w') as f:

f.write(to_str(bytes_ex))

How to Get and Change the Current Working Directory | Python

SungjaeMarch 1, 2016March 1, 2016

How to Get?the Current Working Directory

import os
os.getcwd()

1 2	import os os.getcwd()

How to Change?the Current Working Directory

import os
os.chdir("C:\\Users\\phoen\\datasci_course_materials\\assignment1")

1 2	import os os.chdir("C:\\Users\\phoen\\datasci_course_materials\\assignment1")

Summary for upcoming final exam | Data structure | CS

SungjaeDecember 10, 2014

This post is a summary for the upcoming final exam of Data structure in Computer Science course in Fall, 2014. Summary Range of the final exam Chapter 8?15 in the text book. About chapters Chapter 8: Queues *** Chapter 9: Recursive Thinking *** Chapter 10: Trees ****< Chapter 11: Tree Projects **** Chapter 12: Searching […]

Personality: What makes you the way you are

SungjaeSeptember 3, 2014

Nettle, D. (2009)?Personality: What makes you the way you are. Oxford University Press Key words personality, Big Five (personality traits), openness, conscientiousness, extraversion, agreeableness, neuroticism

ICM 2014 Summary | Programs I participated

SungjaeAugust 20, 2014