Question

I’m having a dataframe as like below. I need to extract AveElapsed or Runtime from the dataframe based on the region

    >avg_data
    region  SN      value   AveElapsed      Runtime
    beta    1       32      1372            943.668
    alpha   2       44      1408            966.495
    beta    3       55      1384            951.091
    beta    4       60      1390            954.929
    atp     5       22      1442            924.381

I need to take “AveElapsed” column or “Runtime” column based on the argument.

Below command is working fine. But how I can

    >avg_data[avg_data$region =="beta", "AveElapsed"]
    [1] 1372 1408 1384 1390 1442

But when I use function

    newfun(z, h)
    {
            avg_data[avg_data$region == z, h]
    }

When I call this function

    newfun(beta, AveElapsed)

I’m getting error like this.. Please advise.

    Error in "[.data.frame"(avg_data, avg_data$region == z, h) :
             object "beta" not found

Also When I tried using as like below it is not working..

    M=AveElapsed
    avg_data[avg_data$region == "beta", M]

Answer 1

That’s because object beta doesn’t exist.

Try this:

newfun("beta", "AveElapsed")

That passes a character object containing the string “beta” rather than the contents of a (non-existent) object called beta. Same goes for “AveElapsed” as @BenBarnes points out.