I just want to select the max value from each column, so the dimension of the result will be same as the amount of column.
you can use apply(MY_DATA, 2, max)
for example with mtcars
a default dataset build into R
> apply(mtcars,2, max)
mpg cyl disp hp drat wt qsec vs am gear carb
33.900 8.000 472.000 335.000 4.930 5.424 22.900 1.000 1.000 5.000 8.000
The apply
function applies a function row-by-row (1
) or column-by-column (2
). Here I'm applying a function that returns the maximum on a column-by-column basis.