Fix 'variable z_ already defined' error in loop












1















My code in Stata initially opens each file using a foreach loop that imports the files while erasing the first line for each file (not shown here).



Once this part is done, my 901 files have the following structure:



 v1 v2  v3  v4  v5  ...
id 798 578 948 421
2000 4567 8673 4806 9405
2001 5867 9001 5893 8790
2002 6878 9233 5712 7678
...


Then, I use this nested foreach loop, which was provided as an answer to a previous question of mine, to rename variables:



ds v*
local i 0
foreach var in `r(varlist)' {
local ++i
tostring v`i', replace
local varname = strtoname(v`i'[1])
rename v`i' z`varname'
}


However, I get this error message:




'variable z_ already defined'.




I ran a set trace on command to make sure that the problem is with the rename command (because z_ cannot already be defined). The problem is indeed with this command. The same code worked perfectly fine before with another group of files so I don't understand.



I want my code to take the first line, to add z_ as a prefix to the number on the first line and to rename my variables (zid for v1, z_798 for v3, z_578 for v3 and so on).





EDIT:



It seems that the problem would be in one specific file:



v1  v2  v3  v4  v5   …
Id 576 . 568 . …
2000 5958 937 949 161
2001 8471 1059 767 234



v3 would become z_ and v5 would become also z_ but it cannot since ‘variable z_ already defined’. It seems that some id numbers are missing.



Any suggestions to fix the code/data?










share|improve this question





























    1















    My code in Stata initially opens each file using a foreach loop that imports the files while erasing the first line for each file (not shown here).



    Once this part is done, my 901 files have the following structure:



     v1 v2  v3  v4  v5  ...
    id 798 578 948 421
    2000 4567 8673 4806 9405
    2001 5867 9001 5893 8790
    2002 6878 9233 5712 7678
    ...


    Then, I use this nested foreach loop, which was provided as an answer to a previous question of mine, to rename variables:



    ds v*
    local i 0
    foreach var in `r(varlist)' {
    local ++i
    tostring v`i', replace
    local varname = strtoname(v`i'[1])
    rename v`i' z`varname'
    }


    However, I get this error message:




    'variable z_ already defined'.




    I ran a set trace on command to make sure that the problem is with the rename command (because z_ cannot already be defined). The problem is indeed with this command. The same code worked perfectly fine before with another group of files so I don't understand.



    I want my code to take the first line, to add z_ as a prefix to the number on the first line and to rename my variables (zid for v1, z_798 for v3, z_578 for v3 and so on).





    EDIT:



    It seems that the problem would be in one specific file:



    v1  v2  v3  v4  v5   …
    Id 576 . 568 . …
    2000 5958 937 949 161
    2001 8471 1059 767 234



    v3 would become z_ and v5 would become also z_ but it cannot since ‘variable z_ already defined’. It seems that some id numbers are missing.



    Any suggestions to fix the code/data?










    share|improve this question



























      1












      1








      1








      My code in Stata initially opens each file using a foreach loop that imports the files while erasing the first line for each file (not shown here).



      Once this part is done, my 901 files have the following structure:



       v1 v2  v3  v4  v5  ...
      id 798 578 948 421
      2000 4567 8673 4806 9405
      2001 5867 9001 5893 8790
      2002 6878 9233 5712 7678
      ...


      Then, I use this nested foreach loop, which was provided as an answer to a previous question of mine, to rename variables:



      ds v*
      local i 0
      foreach var in `r(varlist)' {
      local ++i
      tostring v`i', replace
      local varname = strtoname(v`i'[1])
      rename v`i' z`varname'
      }


      However, I get this error message:




      'variable z_ already defined'.




      I ran a set trace on command to make sure that the problem is with the rename command (because z_ cannot already be defined). The problem is indeed with this command. The same code worked perfectly fine before with another group of files so I don't understand.



      I want my code to take the first line, to add z_ as a prefix to the number on the first line and to rename my variables (zid for v1, z_798 for v3, z_578 for v3 and so on).





      EDIT:



      It seems that the problem would be in one specific file:



      v1  v2  v3  v4  v5   …
      Id 576 . 568 . …
      2000 5958 937 949 161
      2001 8471 1059 767 234



      v3 would become z_ and v5 would become also z_ but it cannot since ‘variable z_ already defined’. It seems that some id numbers are missing.



      Any suggestions to fix the code/data?










      share|improve this question
















      My code in Stata initially opens each file using a foreach loop that imports the files while erasing the first line for each file (not shown here).



      Once this part is done, my 901 files have the following structure:



       v1 v2  v3  v4  v5  ...
      id 798 578 948 421
      2000 4567 8673 4806 9405
      2001 5867 9001 5893 8790
      2002 6878 9233 5712 7678
      ...


      Then, I use this nested foreach loop, which was provided as an answer to a previous question of mine, to rename variables:



      ds v*
      local i 0
      foreach var in `r(varlist)' {
      local ++i
      tostring v`i', replace
      local varname = strtoname(v`i'[1])
      rename v`i' z`varname'
      }


      However, I get this error message:




      'variable z_ already defined'.




      I ran a set trace on command to make sure that the problem is with the rename command (because z_ cannot already be defined). The problem is indeed with this command. The same code worked perfectly fine before with another group of files so I don't understand.



      I want my code to take the first line, to add z_ as a prefix to the number on the first line and to rename my variables (zid for v1, z_798 for v3, z_578 for v3 and so on).





      EDIT:



      It seems that the problem would be in one specific file:



      v1  v2  v3  v4  v5   …
      Id 576 . 568 . …
      2000 5958 937 949 161
      2001 8471 1059 767 234



      v3 would become z_ and v5 would become also z_ but it cannot since ‘variable z_ already defined’. It seems that some id numbers are missing.



      Any suggestions to fix the code/data?







      stata






      share|improve this question















      share|improve this question













      share|improve this question




      share|improve this question








      edited Nov 20 '18 at 0:40









      Pearly Spencer

      10.9k173461




      10.9k173461










      asked Nov 19 '18 at 23:17









      windyboowindyboo

      315




      315
























          1 Answer
          1






          active

          oldest

          votes


















          1














          When you have missing values you can do the following:



          clear 

          input str10(v1 v2 v3 v4 v5)
          id 798 . 948 .
          2000 4567 8673 4806 9405
          2001 5867 9001 5893 8790
          2002 6878 9233 5712 7678
          end

          ds v*
          local i 0
          foreach var in `r(varlist)' {
          local ++i
          local varname = strtoname(v`i'[1])
          if "`varname'" == "_" local varname `i'
          rename v`i' z`varname'
          }

          list

          +------------------------------------+
          | zid z_798 z3 z_948 z5 |
          |------------------------------------|
          1. | id 798 . 948 . |
          2. | 2000 4567 8673 4806 9405 |
          3. | 2001 5867 9001 5893 8790 |
          4. | 2002 6878 9233 5712 7678 |
          +------------------------------------+


          Essentially, you replace the missing value with the value from the counter i.






          share|improve this answer


























          • You answers are always helpful and appreciated!

            – windyboo
            Nov 20 '18 at 1:07











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          1 Answer
          1






          active

          oldest

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          active

          oldest

          votes






          active

          oldest

          votes









          1














          When you have missing values you can do the following:



          clear 

          input str10(v1 v2 v3 v4 v5)
          id 798 . 948 .
          2000 4567 8673 4806 9405
          2001 5867 9001 5893 8790
          2002 6878 9233 5712 7678
          end

          ds v*
          local i 0
          foreach var in `r(varlist)' {
          local ++i
          local varname = strtoname(v`i'[1])
          if "`varname'" == "_" local varname `i'
          rename v`i' z`varname'
          }

          list

          +------------------------------------+
          | zid z_798 z3 z_948 z5 |
          |------------------------------------|
          1. | id 798 . 948 . |
          2. | 2000 4567 8673 4806 9405 |
          3. | 2001 5867 9001 5893 8790 |
          4. | 2002 6878 9233 5712 7678 |
          +------------------------------------+


          Essentially, you replace the missing value with the value from the counter i.






          share|improve this answer


























          • You answers are always helpful and appreciated!

            – windyboo
            Nov 20 '18 at 1:07
















          1














          When you have missing values you can do the following:



          clear 

          input str10(v1 v2 v3 v4 v5)
          id 798 . 948 .
          2000 4567 8673 4806 9405
          2001 5867 9001 5893 8790
          2002 6878 9233 5712 7678
          end

          ds v*
          local i 0
          foreach var in `r(varlist)' {
          local ++i
          local varname = strtoname(v`i'[1])
          if "`varname'" == "_" local varname `i'
          rename v`i' z`varname'
          }

          list

          +------------------------------------+
          | zid z_798 z3 z_948 z5 |
          |------------------------------------|
          1. | id 798 . 948 . |
          2. | 2000 4567 8673 4806 9405 |
          3. | 2001 5867 9001 5893 8790 |
          4. | 2002 6878 9233 5712 7678 |
          +------------------------------------+


          Essentially, you replace the missing value with the value from the counter i.






          share|improve this answer


























          • You answers are always helpful and appreciated!

            – windyboo
            Nov 20 '18 at 1:07














          1












          1








          1







          When you have missing values you can do the following:



          clear 

          input str10(v1 v2 v3 v4 v5)
          id 798 . 948 .
          2000 4567 8673 4806 9405
          2001 5867 9001 5893 8790
          2002 6878 9233 5712 7678
          end

          ds v*
          local i 0
          foreach var in `r(varlist)' {
          local ++i
          local varname = strtoname(v`i'[1])
          if "`varname'" == "_" local varname `i'
          rename v`i' z`varname'
          }

          list

          +------------------------------------+
          | zid z_798 z3 z_948 z5 |
          |------------------------------------|
          1. | id 798 . 948 . |
          2. | 2000 4567 8673 4806 9405 |
          3. | 2001 5867 9001 5893 8790 |
          4. | 2002 6878 9233 5712 7678 |
          +------------------------------------+


          Essentially, you replace the missing value with the value from the counter i.






          share|improve this answer















          When you have missing values you can do the following:



          clear 

          input str10(v1 v2 v3 v4 v5)
          id 798 . 948 .
          2000 4567 8673 4806 9405
          2001 5867 9001 5893 8790
          2002 6878 9233 5712 7678
          end

          ds v*
          local i 0
          foreach var in `r(varlist)' {
          local ++i
          local varname = strtoname(v`i'[1])
          if "`varname'" == "_" local varname `i'
          rename v`i' z`varname'
          }

          list

          +------------------------------------+
          | zid z_798 z3 z_948 z5 |
          |------------------------------------|
          1. | id 798 . 948 . |
          2. | 2000 4567 8673 4806 9405 |
          3. | 2001 5867 9001 5893 8790 |
          4. | 2002 6878 9233 5712 7678 |
          +------------------------------------+


          Essentially, you replace the missing value with the value from the counter i.







          share|improve this answer














          share|improve this answer



          share|improve this answer








          edited Nov 20 '18 at 0:41

























          answered Nov 20 '18 at 0:27









          Pearly SpencerPearly Spencer

          10.9k173461




          10.9k173461













          • You answers are always helpful and appreciated!

            – windyboo
            Nov 20 '18 at 1:07



















          • You answers are always helpful and appreciated!

            – windyboo
            Nov 20 '18 at 1:07

















          You answers are always helpful and appreciated!

          – windyboo
          Nov 20 '18 at 1:07





          You answers are always helpful and appreciated!

          – windyboo
          Nov 20 '18 at 1:07




















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