I have the following data frame which I called ozone:
Ozone Solar.R Wind Temp Month Day
1 41 190 7.4 67 5 1
2 36 118 8.0 72 5 2
3 12 149 12.6 74 5 3
4 18 313 11.5 62 5 4
5 NA NA 14.3 56 5 5
6 28 NA 14.9 66 5 6
7 23 299 8.6 65 5 7
8 19 99 13.8 59 5 8
9 8 19 20.1 61 5 9
I would like to extract the highest value from ozone
, Solar.R
, Wind
…
Also, if possible how would I sort Solar.R
or any column of this data frame in descending order
I tried
max(ozone, na.rm=T)
which gives me the highest value in the dataset.
I have also tried
max(subset(ozone,Ozone))
but got "subset" must be logical."
I can set an object to hold the subset of each column, by the following commands
ozone <- subset(ozone, Ozone >0)
max(ozone,na.rm=T)
but it gives the same value of 334, which is the max value of the data frame, not the column.
Any help would be great, thanks.
Best Answer
Similar to
colMeans
,colSums
, etc, you could write a column maximum function,colMax
, and a column sort function,colSort
.I use
...
in the second function in hopes of sparking your intrigue.Get your data:
Use
colMax
function on sample data:To do the sorting on a single column,
and over all columns use our
colSort
function,