opiStaticStimulus: Stimulus parameter list.

Description Details Author(s) References See Also Examples


List containing stimulus parameters with an S3 class attribute of opiStaticStimulus.


The list must 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

level stimulus level in cd/m^2 (ignored if !is.na(image))

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

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

duration total stimulus duration in milliseconds maximum

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

... machine specific parameters

SimHenson and SimGaussian

Only level is used. Duration and location are ignored, color is assumed "white" and size is assumed to be 26/60 (Goldmann III).

Octopus 900

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

image is not possible on an Octopus 900.

level is in cd/m^2, and is rounded to the nearest one tenth of a dB for display.

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

Octopus 900 F310 Controller

As for the Octopus 900, but a responseWindow of -1 means that the Octopus 900 server will wait until either the L and R button is pressed in the controller until returning.

Kowa AP 7000

x and y are in degrees. (precision?)

image is not possible on an Kowa AP 7000.

level are in cd/m^2 in the range 0.03 to 3183, nearest one tenth of a dB for display.

size is in degrees, but is rounded to the nearest Goldmann Size I..V for display.

color one of .KowaAP7000Env$COLOR_WHITE, .KowaAP7000Env$COLOR_GREEN, .KowaAP7000Env$COLOR_BLUE, and .KowaAP7000Env$COLOR_RED.


x, y, level, size, and color are not used.

image is a list of two matrices: the first for the right eye, the second for the left. Each image is a 1080x1080 matrix with each element in the range 0 to 80, which maps onto 0dB to 40dB in steps of 0.5dB. Thus 0 is 0dB, 3283.048 cd/m^2; 1 is 0.5dB; and 80 is 40dB, 10 cd/m^2.

tracking is TRUE if auto image placement to keep pupil centred is used, or FALSE to turn off imo auto-image placement to keep centred on pupil.


Andrew Turpin <[email protected]>


Please cite: A. Turpin, P.H. Artes and A.M. McKendrick "The Open Perimetry Interface: An enabling tool for clinical visual psychophysics", Journal of Vision 12(11) 2012.


See Also



    stim <- list(x=9, y=9, image=NA, 314, size=0.43, color="white", 
                duration=200, responseWindow=1500)
    class(stim) <- "opiStaticStimulus"

OPI documentation built on May 30, 2017, 12:35 a.m.