Add empty columns to a dataframe with specified names from a vector

Question

I have a dataframe  df  with a a number of columns of data already  I have a vector  namevector  full of strings  I need empty columns added to df with the names of the columns from namevector  I am trying to add columns with this for loop  iterating over each string in namevector  for  i in length namevector       df   i   lt - NA    but am left with this error   Error in   lt - data frame  tmp     i  value   NA    new columns would leave holes after existing columns  Alternatively  I have thought of creating an empty dataframe with the correct names  then cbind-ing the two dataframes together but am not sure how to go about coding this  How would I go about resolving this

User · Answer

Maybe   df  lt - do call  cbind   list df  rep list NA  length namevector     colnames df  -1  1  ncol df  - length namevector      lt - namevector

User · Answer

The problem with your code is in the line   for i in length namevector     You need to ask yourself  what is length namevector   It s one number  So essentially you re saying   for i in 11  df  i   lt - NA   Or more simply   df  11   lt - NA   That s why you re getting an error  What you want is   for i in namevector      df  i   lt - NA   Or more simply   df  namevector   lt - NA

User · Answer

set seed 1  example  lt - data frame col1   rnorm 10  0  1   col2   rnorm 10  2  3   namevector  lt - c  col3    col4   example    namevector   lt - NA  example            col1       col2 col3 col4   1  -0 6264538  6 5353435   NA   NA   2   0 1836433  3 1695297   NA   NA   3  -0 8356286  0 1362783   NA   NA   4   1 5952808 -4 6440997   NA   NA   5   0 3295078  5 3747928   NA   NA   6  -0 8204684  1 8651992   NA   NA   7   0 4874291  1 9514292   NA   NA   8   0 7383247  4 8315086   NA   NA   9   0 5757814  4 4636636   NA   NA   10 -0 3053884  3 7817040   NA   NA

User · Answer

The below works for me  dataframe   newName    lt - NA   Make sure to add    for new name string

[r] Add empty columns to a dataframe with specified names from a vector

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