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I have a couple of questions about microbenchmark and autoplot

Suppose this is my code:

library("ggplot2")
tm <- microbenchmark(rchisq(100, 0),rchisq(100, 1),rchisq(100, 2),rchisq(100, 3),rchisq(100, 5), times=1000L)
autoplot(tm)
  1. What are the units in tm$time? how can i convert that to seconds?
  2. How can I change the marks on the x axis to something like seq(from=0, to=100,by = 5)?

Thanks!

Ignacio
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1 Answers1

6

help(microbenchmark) gives:

1.  ‘time’ is the measured execution time
    of the expression in nanoseconds.

NANOseconds not milliseconds or microseconds.

So divide by 1000000000 to convert to seconds.

And for your second question, my first response is "why?". But its ggplot-based, so you can override bits by adding ggplot things:

 autoplot(tm) + scale_y_log10(name="seq(whatever)")

Note the plot is rotated so the x-axis is the y-scale....

I've just thought you really mean "tick marks"? Slightly different but doable, but not really appropriate given the log axis. You can force a non-log axis with specified tick marks:

 autoplot(tm) + scale_y_continuous(breaks=seq(0,10000,len=5),name="not a log scale")

You can keep the log scale and set the tick mark points:

 autoplot(tm) + scale_y_log10(breaks=c(50,200,500))
Spacedman
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  • can you please take a look at my question? https://stackoverflow.com/questions/65458335/r-using-microbenchmark-and-ggplot2-to-plot-runtimes thanks – stats_noob Dec 26 '20 at 16:27