Comment line and comment paragraph 
////////////////////////////////
A good comment would make your program more readable


Method 1:Anything after # will be a command

   > pv=10   # pv is for present value

Method II: a pair of double quotation marks

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3 ways to assign a value/values and how to show its value
////////////////////////////////
Three methods: 

  Method I:  >pv=100

  Method II: >r<-0.1

  Method III:>10->n 

  To show the value of a variable, type its name

    > pv=100
    > pv
      [1] 100

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Use up and down arrow keys to recall the previous commands 
////////////////////////////////

 We could use up and down arrow keys to recall 
    our previous commands. 

 Thus, we could save time by recalling the previous command and modify it a little bit. 

  > pv= 100
  > r = 0.1
  > n = 2
  > fv_f(pv,r,n)
     [1] 121

  > pv= 200
  > fv_f(pv,r,n)
    [1] 242
  > 
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R is case sensitive 
////////////////////////////////
Case sensitive means that pv is different from PV

  > pv=100

  > PV
    Error: object 'PV' not found

  > 

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Links 
///////////////////////////////////////////////
 Downoad git to your computer
    https://git-scm.com/downloads
    https://git-scm.com/download/win
 Documentation
    https://git-scm.com/doc
    https://git-scm.com/documentation

  https://git-scm.com/book/en/v2/Git-Basics-Getting-a-Git-Repository
  git help (git >t.txt)

c:\Users\pyan\AppData\Local\Programs\Git\bin\git.exe version
git version 2.39.0.windows.2
///////////////////////////////////////////////

Links 
////////////////////////////////
R download:
    http://r-project.org
RStudio download
   https://posit.co/download/rstudio-desktop/

My website          http://datayyy.com/webs/R.shtml
An Introduction to R 
      http://datayyy.com/doc_pdf/R-intro.pdf
R Language Definition 
      http://datayyy.com/doc_pdf/R-lang.pdf
One programming language:
      http://canisius.edu/~yany/doc/one_language.pdf
R, Python or SAS: Which one should you learn first?
      https://www.edvancer.in/r-python-or-sas-which-one-should-you-learn-first/
      http://canisius.edu/~yany/doc/whichonefirst.pdf
SAS vs. R (vs. Python)
      https://www.analyticsvidhya.com/blog/2014/03/sas-vs-vs-python-tool-learn/
      http://canisius.edu/~yany/doc/comparion_02.pdf
My slides for week 1
    http://datayyy.com/doc_pdf/fmur1.pdf
    or
    http://canisius.edu/~yany/doc/fmur1.pdf
Old syllabus
    http://datayyy.com/doc_pdf/syllabus694.pdf
chapter 1
   http://datayyy.com/doc_pdf/chapter01.pdf
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