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I want to get the minimum of two columns and create a column in the same data.frame. How can I do that?
For example:
ID Parm1 Parm2 1 1 2 2 0 1 3 2 1 4 1 0 5 2 0 Desired output :
ID Parm1 Parm2 Min 1 1 2 1 2 0 1 0 3 2 1 1 4 1 0 0 5 2 0 0 
512
with ID/Col as the primary key (and possibly Col as an extra key, depending on your needs). Then your query becomes a simple select min(val) from tbl and you can still treat the individual 'old columns' separately by using where col = 2 in your other queries.
a) Find the minimum value among rows and columns :Dataframe. min() : This function returns the minimum of the values in the given object. If the input is a series, the method will return a scalar which will be the minimum of the values in the series.
To find the minimum value of a column, use the MIN() aggregate function; it takes as its argument the name of the column for which you want to find the minimum value. If you have not specified any other columns in the SELECT clause, the minimum will be calculated for all records in the table.
You want the parallel minimum implemented in function pmin(). For example using your data:
dat <- read.table(text = "ID Parm1 Parm2 1 1 2 2 0 1 3 2 1 4 1 0 5 2 0", header = TRUE) you can use transform() to add the min column as the output of pmin(Parm1, Parm2) and access the elements of dat without indexing:
dat <- transform(dat, min = pmin(Parm1, Parm2)) This gives:
> dat ID Parm1 Parm2 min 1 1 1 2 1 2 2 0 1 0 3 3 2 1 1 4 4 1 0 0 5 5 2 0 0 If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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