change column values in list of dataframes in R
问题 I have a list of 12 dataframes. the name of the list is kvish_1_10t.tables . each data frame has a column "day_mean" (always the 7's column in all the dataframes). its impotant to say that all the dataframes look exacly the same. this is an example of one of the tables: X2014_kvish_1_10t kvish keta maslul yom nefah date day_mean 1 1 10 1 1 1936 2014-09-07 00:00:00 2910.958 2 1 10 1 1 966 2014-09-07 01:00:00 2910.958 3 1 10 1 1 737 2014-09-07 02:00:00 2910.958 4 1 10 1 1 596 2014-09-07 03:00