Dark (version 0.9.4)

Start: Start

Description

A function to build an array of starting parameters from a dark object.

Usage

Start(obj, Reps)

Arguments

obj

A dark object

Reps

The number of rows in the array.

Value

• Output is an array of seven columns and number of rows = 'Reps'.

Details

The array of starting parameters is built from the time and threshold data in the object, obj.

Each parameter is assumed to have a possible range given the data.

Each range is constructed as follows; the time points; alpha (cone-rod transition $\alpha$ minutes) and beta (rod-rod transition $\beta$ minutes) are assumed to fall in the first and second halves of the time data respectively (obj$time).

The cone threshold is assumed to be in the upper half of the threshold data (obj$thrs log units). The cone coefficient (log units) or threshold at time zero is presumed to be positive and the same values are used for the time constants ($tau$ minutes).

The rate of rod recovery S2, and the combined parameter -(S2 + S3) are ranged between -0.6 and 0 log units/minute.

These ranges of possible values are complied into an array by sampling without replacement from each range for each parameter.

Examples

set.seed(1234)
tmp<-TestData(0:20)
Start(tmp, 10)