Dividing rows of a dataset by a column value

Here i wish to divide the value in each row by the corresponding daily (each row is a day) maximum value, how would i do this? Finding it tricky as i dont want to divide the first 2 columns of the data by this. Data snipet below;

so i want to divide each of the values in each row by the max in each row but avoiding the date and substation

Date         Substation `00:00` `00:10` `00:20` `00:30` `00:40` `00:50` `01:00` `01:10` `01:20`   max
 <date>          <int>   <dbl>   <dbl>   <dbl>   <dbl>   <dbl>   <dbl>   <dbl>   <dbl>   <dbl>   <dbl>
 1 2013-01-03     511016   257.   259.    264.    263.    248.     239.   243.     230.   228.    264.  
 2 2013-01-03     511029    96    111.    116.     99.0   123.     128.   130.     126.   116.    130.  
 3 2013-01-03     511030   138.   129.    127.    124.    119.     126.   125.     121.   112.    138.  
 4 2013-01-03     511033   172.   165.    167.    170.    171.     173.   173.     166.   157.    173.  
 5 2013-01-03     511034   302.   298.    302.    290.    291.     287.   280.     291.   277.    302.  
 6 2013-01-03     511035   116.   131.    130.    121.    116.     108.   106.     112.   109.    131.

>Solution :

With pmax and do.call:

df[-c(1, 2)] / do.call(pmax, df[-c(1, 2)])

Or, you can apply a function, x / max(x), for each rows (MARGIN = 1) of your selected columns (df[-c(1, 2)]) using apply.

t(apply(df[-c(1, 2)], 1, function(x) x / max(x)))