I would like to limit the number of decimals of SNP array signal when a data frame is imported. My .txt input have 16 decimals to each row in collumn "Value". In a same collumns it can have numbers and strings (Non called intensities = NC), at same time. My dataframe look like that:

Value
0.202021561664556
0.202021561664556
0.202021561664556
0.202021561664556
NC
...

My expected dataframe

Value
0.20202156
0.20202156
0.20202156
0.20202156
NC
...

Real input (DF) that not works:

DF <- "NE001358.Log.R.Ratio
    -0.0970369274475688
    0.131893549586039
    0.0629266495860389
    0.299559132381831
    -0.0128804337656807
    0.0639743960526874
    0.0271669351886552
    0.322395363972391
    0.179591292893632
            NC"

DF <- read.table(text=DF, header = TRUE)