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Cheng ChengLuFred

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  • Stevens Institute of Technology
  • Hoboken
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@ChengLuFred
ChengLuFred / windows_configure.md
Last active September 14, 2021 09:24
[Windows] #Windows

Screen shot autosave

windows + PrintScreen

This command autosaves the current screen shot into C:\Users\cheng\Pictures\Screenshots

@ChengLuFred
ChengLuFred / Moment.md
Last active July 11, 2020 21:51
[Math Note] #Math

Moment for Gaussian distributed variable $X \sim \mathcal{N}\left(0, \sigma^{2}\right)$ $$E\left[X^{2 n}\right]=(2 n-1) ! ! \sigma^{2 n}$$

@ChengLuFred
ChengLuFred / quantmod.md
Last active April 3, 2020 21:18
[Quantmod] #R

Download Data

Download stock prices from yahoo finance

getSymbols.yahoo(Symbols = "MSFT",
                 env = globalenv(),
                 index.class  = 'Date',
                 from = "1980-01-01",
                 to = "2019-12-31",
                 periodicity = "daily")
@ChengLuFred
ChengLuFred / path.md
Last active June 25, 2020 19:59
[Path Management] #Python

check path validation

if not os.path.exists(OUTPUT_FILE_PATH):
            os.makedirs(OUTPUT_FILE_PATH)
            if verbose:
                print('Path: {0} created'.format(OUTPUT_FILE_PATH))
  • path containing number need double slash \\ before number



  


  




    


          
    

      

        
        

          

              @ChengLuFred
          

          

            
                ChengLuFred
                / read_data_r.md
            
            

              Created
              April 15, 2020 01:38
            

              
                [Read Data in R] read .csv etc. tables into R #R
              
          

        

      

        

  

      

    
row.names argument also can be number denoting which column to be used as index


data <- read.csv('homework05.csv', header = TRUE, row.names = c('DATE'))



  


  




    


          
    

      

        
        

          

              @ChengLuFred
          

          

            
                ChengLuFred
                / file_manage_python.md
            
            

              Last active
              December 1, 2020 19:54
            

              
                [File Management in Python]file combine, zip extract, etc. #Python
              
          

        

      

        

  

      

    
1. Quick way to read file using pandas


file_name = 'file_name.csv'
tickers_info = pd.read_csv(file_name,
                           sep = ",",			 # ',' for csv file and '\t' for text file
						   header = 0,			 # row number used as head
                           usecols=[1, 2], 		 # column index to be included
                           index_col = [0], 	 # column index which apdated above
 engine='c') # c engine is faster than python



  


  




    


          
    

      

        
        

          

              @ChengLuFred
          

          

            
                ChengLuFred
                / cheat sheet.md
            
            

              Last active
              June 21, 2020 02:30
            

              
                [Math Syntax in Latex] #Latex
              
          

        

      

        

  

      

    
<object data="http://yoursite.com/the.pdf" type="application/pdf" width="700px" height="700px">
    <embed src="http://yoursite.com/the.pdf">
        <p>This browser does not support PDFs. Please download the PDF to view it: <a href="http://yoursite.com/the.pdf">Download PDF</a>.</p>
    </embed>




  


  




    


          
    

      

        
        

          

              @ChengLuFred
          

          

            
                ChengLuFred
                / **kwarg.md
            
            

              Last active
              June 21, 2020 03:22
            

              
                [Pass variable number of parameters] #Python
              
          

        

      

        

  

      

    
*args pass a list of values or variables


**kwarg(key words arguments) pass a dictionary


def test_args_kwargs(arg1, arg2, arg3):
    print("arg1:", arg1)
    print("arg2:", arg2)
    print("arg3:", arg3)

# test *args



  


  




    


          
    

      

        
        

          

              @ChengLuFred
          

          

            
                ChengLuFred
                / cheat sheet.md
            
            

              Last active
              January 14, 2024 05:42
            

              
                [Markdown Cheat Sheet] #Markdown
              
          

        

      

        

  

      

    
    

  1. 

    Markdown
markdown
    

    2. 

  2. 

    R markdown
rmarkdown
    

    3. 




  


  




    


          
    

      

        
        

          

              @ChengLuFred
          

          

            
                ChengLuFred
                / cheat_sheet.md
            
            

              Last active
              June 23, 2020 17:30
            

              
                [Cheat Sheet for WSL] often used option #cmd
              
          

        

      

        

  

      

    
    

  • switch between WSL(Ubuntu) and CMD(Windows)
    • 



$ cmd.exe # to change to windows cmd
$ wsl.exe # to change to wsl ubuntu terminal