Tukukkk

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?

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.