Millisecond Forums

add spatial gaussian noise

https://www.millisecond.com/forums/Topic29470.aspx

By nakayama - 7/21/2020

Hi, Dave
I wish to ask whether it is possible to add a gaussian distributed noise to the values. errordis which is defined as the distance between the clicked position and the start position.
For example, If the values.errordis is 500 pixel. I wish to add a gaussian noise centered on 500 pixel  with a standard deviation of 10 pixel.
So the final recorded value is, say, 505, due to the added noise.
My file is attached below.
Thank you for your attention.
By Dave - 7/21/2020

nakayama - 7/21/2020
Hi, Dave
I wish to ask whether it is possible to add a gaussian distributed noise to the values. errordis which is defined as the distance between the clicked position and the start position.
For example, If the values.errordis is 500 pixel. I wish to add a gaussian noise centered on 500 pixel  with a standard deviation of 10 pixel.
So the final recorded value is, say, 505, due to the added noise.
My file is attached below.
Thank you for your attention.

https://www.millisecond.com/support/docs/v5/html/language/functions/randgaussian.htm

I.e. something like this:

<data>
/ columns=[values.errordis values.errordis_plus_noise]
/ separatefiles = true
</data>

<values>
/ax=0
/ay=0
/errordis=0
/errordis_plus_noise=0
/ initialx=960
/ initialy=600
</values>



<trial click>
/ ontrialend = [trial.click.resetstimulusframes()]
/ validresponse = (screen)
/ stimulustimes = [0=screen,posx,posy,pose]
/ ontrialend = [values.errordis = sqrt(pow(trial.click.responsex-values.initialx,2)+pow(trial.click.responsey-values.initialy,2))]
/ ontrialend = [
    values.errordis_plus_noise = randgaussian(values.errordis, 10);
]

/ ontrialend = [values.ax=trial.click.responsex; values.ay=trial.click.responsey]
/ responseinterrupt = frames
/ inputdevice = mouse
/ screencapture = true
</trial>