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Looping through data error

7 messages · jim holtman, Rui Barradas, e-mail ma015k3113 +1 more

Original
e-mail ma015k3113
# 
Dear All,I have a dataframe with 4 variables and I am trying to calculate how many shares can be purchased with ?100 in the first year when the company was listed

The data looks like:

COMPANY_NUMBER YEAR_END_DATE CLOSE_SHARE_PRICE  NUMBER_OF_SHARES
22705                                30/09/2002                          NA                                 0
22705                                30/09/2004                         NA                                  0
22705                                30/09/2005                        6.55                                 0
22705                                30/09/2006                        7.5                                   0
22705                                30/09/2007                        9.65                                 0
22705                                30/09/2008                        6.55                                 0
1091347                            31/01/2010                        8.14                                 0
1091347                             31/01/2011                      11.38                                 0
11356069                           30/06/2019                      1.09                                   0
SC192761                         31/01/2000                         NA                                   0
SC192761                         31/01/2001                         NA                                   0
SC192761                          31/01/2002                        NA                                   0
SC192761                         31/01/2004                         NA                                   0
SC192761                         31/01/2005                         NA                                   0
SC192761                          31/01/2006                      1.09                                   0
SC192761                          31/01/2008                      1.24                                   0
SC192761                          31/01/2009                       0.9                                    0
SC192761                          31/01/2010                     1.14                                    0
SC192761                           31/01/2011                    1.25                                    0
SC192761                          31/01/2012                     1.29                                    0


The code I have written is

i <- 0

for (i in 1:(nrow(PLC_Return)-1))
if (i == 1)
{
NUMBER_OF_SHARES[i] = 100/is.na(CLOSE_SHARE_PRICE[i])
} else if
(is.na(PLC_Return[i, 1]) == is.na(PLC_Return[i + 1, 1])
{
NUMBER_OF_SHARES[i]=0
} else
{
NUMBER_OF_SHARES[i] = 100/is.na(CLOSE_SHARE_PRICE[i])
}


The error I get is Error: unexpected 'else' in:

" NUMBER_OF_SHARES[i] = 0
} else"
Error: unexpected '}' in "}"


Don't know how to fix it-any help will be appreciated.


Kind regards


Ahson
jim holtman
# 
Your code was formatted incorrectly.  There is always a problem with the
'else' statement after an 'if' since in R there is no semicolon to mark the
end of a line.  Here might be a better format for your code.  I would
recommend the liberal use of "{}"s when using 'if/else'



i <- 0

for (i in 1:(nrow(PLC_Return) - 1)) {
  if (i == 1) {
    NUMBER_OF_SHARES[i] = 100 / is.na(CLOSE_SHARE_PRICE[i])
  } else {
    if (is.na(PLC_Return[i, 1]) == is.na(PLC_Return[i + 1, 1]) {
      NUMBER_OF_SHARES[i] = 0
    } else {
      NUMBER_OF_SHARES[i] = 100 / is.na(CLOSE_SHARE_PRICE[i])
    }
  }
}


Jim Holtman
*Data Munger Guru*


*What is the problem that you are trying to solve?Tell me what you want to
do, not how you want to do it.*


On Tue, Apr 13, 2021 at 5:51 AM e-mail ma015k3113 via R-help <
r-help at r-project.org> wrote:

            

      
      
      
    

        

      
      
    

        

  
  


  


      

    

    

      
      

        


  

        

      Rui Barradas
    

    

      
      #
    

  


  

      
Hello,

A close parenthesis is missing in the nd if.


for (i in 1:(nrow(PLC_Return)-1)){
   if (i == 1){
     NUMBER_OF_SHARES[i] = 100/is.na(CLOSE_SHARE_PRICE[i])
   } else if(is.na(PLC_Return[i, 1]) == is.na(PLC_Return[i + 1, 1])){
     NUMBER_OF_SHARES[i]=0
   } else {
     NUMBER_OF_SHARES[i] = 100/is.na(CLOSE_SHARE_PRICE[i])
   }
}


Hope this helps,

Rui Barradas

?s 13:51 de 13/04/21, e-mail ma015k3113 via R-help escreveu:

            

      
      
      
    

        

      
      
    

  
  


  


      

    

    

      
      

        


  

        

      Rui Barradas
    

    

      
      #
    

  


  

      
Hello,

Typo, inline.

?s 17:06 de 13/04/21, Rui Barradas escreveu:

            

      
      
      
    

        
Should be "the 2nd if".

Rui Barradas

            

      
      
      
    

        

      
      
    

            

      
      
      
    

        

      
      
    

  
  


  


      

    

    

      
      

        


  

        

      e-mail ma015k3113
    

    

      
      #
    

  


  

      
Jim, thanks for taking the time to look into this. Yes, these if else statements are so confusing.

I tried your amended scode and it does not work. The error are as follows:


Error: unexpected '}' in " }"

            

      
      
      
    

        
Error: unexpected '}' in " }"

            

      
      
      
    

        
Error: unexpected '}' in " }"

            

      
      
      
    

        
Error: unexpected '}' in "}"

            

      
      
      
    

        
I have spent so much time on this-hopefully I will come to grips sooner or later. In the mean time any further suggestion?


Kind regards


Ahson

            

      
      
      
    

        

      
      
    

        

  
  


  


      

    

    

      
      

        


  

        

      e-mail ma015k3113
    

    

      
      #
    

  


  

      
Rui, excellent diagnosis and suggestion. It worked but my damn logic is still not delivering what I want-will spend more time on it tomorrow.


Kind regards

Ahson

            

      
      
      
    

        

      
      
    

  
  


  


      

    

    

      
      

        


  

        

      Bert Gunter
    

    

      
      #
    

  


  

      
Well, if I understand your query, wouldn't the following simple approach
suffice -- it assumes that the results for each company are ordered by
year, as your example seems to show:

## test is your example data
## first remove NA's
test2 <- na.omit(test)

## Now just use tapply():

            

      
      
      
    

        
+                       FUN =function(x)100 /x[1]))

            

      
      
      
    

        
1091347 11356069    22705 SC192761
12.28501 91.74312 15.26718 91.74312
## essentially a labelled vector
##You can use  %/% if you only want the whole number of shares that can be
purchased

It's somewhat messier if the results are not ordered by date within company
-- you could use by() and POSIXct to order the dates within company to get
the right one.

Cheers,

Bert Gunter

"The trouble with having an open mind is that people keep coming along and
sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


On Tue, Apr 13, 2021 at 11:34 AM e-mail ma015k3113 via R-help <

        
r-help at r-project.org> wrote: