usl (version 1.2.2)

plot,USL-method: Plot the scalability function from a USL model

Description

Create a line plot for the scalability functionh of a Universal Scalability Law model.

Usage

## S3 method for class 'USL':
plot(x, from = NULL, to = NULL, xlab = NULL,
  ylab = NULL, bounds = FALSE, sigma, kappa, ...)

Arguments

x

The USL object to plot.

from

The start of the range over which the scalability function will be plotted.

to

The end of the range over which the scalability function will be plotted.

xlab

A title for the x axis: see title.

ylab

A title for the y axis: see title.

bounds

Add the bounds of scalability to the plot.

sigma

Optional parameter to be used for evaluation instead of the parameter computed for the model.

kappa

Optional parameter to be used for evaluation instead of the parameter computed for the model.

...

Other graphical parameters passed to plot (see par, plot.function).

Details

plot creates a plot of the scalability function for the model represented by the argument x.

If from is not specified then the range starts at the minimum value given to define the model. An unspecified value for to will lead to plot ending at the maximum value from the model. For add = TRUE the defaults are taken from the limits of the previous plot.

xlab and ylab can be used to set the axis titles. The defaults are the names of the regressor and response variables used in the model.

If the parameter bounds is set to TRUE then the plot also shows dotted lines for the theoretical bounds of scalability. These are the linear scalability for small loads and Amdahl's asymptote for the limit of scalability as load approaches infinity.

The parameters sigma or kappa are useful to do a what-if analysis. Setting these parameters override the model parameters and show how the system would behave with a different contention or coherency delay parameter.

See Also

usl, plot.function

Examples

require(usl)

data(raytracer)

## Plot result from USL model for demo dataset
plot(usl(throughput ~ processors, raytracer))