opiTemporalStimulus: Stimulus parameter list

In OPI: Open Perimetry Interface

Stimulus parameter list

Description

List containing stimulus parameters with an S3 class attribute of opiTemporalStimulus

Usage

"See details"

Details

The list should be of class opiTemporalStimulus and contain the following elements.

• x coordinate of the center of stimulus in degrees relative to fixation

• y coordinate of the center of stimulus in degrees relative to fixation

• image an image to display in a machine specific format

• lut if is.na(image) then this is a lookup table (vector) for stimulus level at each step of rate Hz in cd/\mbox{m}^2. If image is specified, then this is a list of images, in the same format as image, that is stepped through at rate Hz.

• size diameter of target in degrees, or scaling factor for image if specified

• color machine specific stimulus color settings (ignored if !is.na(image))

• rate frequency with which lut is processed in Hz

• durationtotal length of stimulus flash in milliseconds. There is no guarantee that duration %% length(lut)/rate == 0. That is, the onus is on the user to ensure the duration is a multiple of the period of the stimuli.

• responseWindow maximum time (>= 0) in milliseconds to wait for a response from the onset of the stimulus presentation

• ... machine specific parameters

Octopus 900

x and y are in degrees, with precision to one decimal place recognised.

image is not possible on an Octopus 900.

lut is not possible on an Octopus 900. Stimulus is at 0 dB.

rate is in Hz, with precision to one decimal place recognised.

color is ignored. Use opiSetBackground() to alter stimulus color.

Kowa AP7000

Not supported.

Compass

Not implemented.

See Also

opiSetBackground, opiStaticStimulus, opiKineticStimulus

Examples

# A Size III flickering with a 10Hz square wave at location (7,7) with luminance
# 10 dB (HFA) 
stim <- list(x=7, y=7, size=0.43, color="white",
             rate=20,        # one lut step per 50 ms
             lut=c(0,318),   # so one full lut per 100 ms == 10Hz
             duration=400,   # and 4 cycles per stimulus
             responseWindow=1500)
class(stim) <- "opiTemporalStimulus"

OPI documentation built on Nov. 7, 2023, 9:06 a.m.