Dark (version 0.9.4)

TestData: Data that can be used to test other scripts.

Description

This script creates data in the form of a dark object from specified times, parameters, and level of variability. It is used for testing and developing other scripts.

Usage

TestData(x, theta, sse, repeatable)

Arguments

x

the times at which observations are made.

theta

the parameters of the Mahroo Lamb Pugh model lccc{ theta : parameter default Units theta[1]: cone threshold -1 (log lum) theta[2]: cone coefficient 1 (log lum) theta[3]: cone time constant 1 (minutes) theta[4]: S2 -0.2

sse

the variability of the data

repeatable

a boolean flag that ensures that the function can return the same values each time it is called.

Value

• The function returns a dark object with the following components;
• call
  a label describing the last call the object was subject to
• time
  the time observations
• thrs
  thresholds
• resid
  residuals
• fit
  thresholds predicted in the absence of noise
• thet
  parameters passed to the function
• sse
  the sum of squared residuals value used to describe the variability in the data
• val
  the actual sse of the generated data
• data
  the name of the data source

Details

The parameters values chosen as defaults are entirely arbitrary. The sixth parameter is the negative sum of the rates of rod recovery called S2 and S3

References

L. Patryas, N. R. Parry, D. Carden, D. H. Baker, J. M. Kelly, T. Aslam, and I. J. Murray. Assessment of age changes and repeatability for computer-based rod dark adaptation. Graefe's Archive for Clinical and Experimental Ophthalmology, pages 1-7, 2013.

Examples

set.seed(1234)
x <- seq(0,20)
tmp <- TestData(x)
tmp