Millisecond Forums

+x

 

lukasg - 1/31/2022

/ hposition = 1px * (display.canvaswidth/2) - 10 * expressions.ratio_pxpermm

In search for a solution I came across previous entries on absolute stimuli sizes. However, I do not see how I can translate this to the present example. The recurring issue is that display.canvaswidth and others provide the total pixel width. Thus, the physical distance in cm will differ across screens?

e.g.:

/ hposition = 1px * (display.canvaswidth/2) - 10 * expressions.ratio_pxpermm

Instead, I would two letters to presented at a horizontal distance of 2cm, for instance.

+x

 

Dave - 1/31/2022

<block myblock>
/ onblockbegin = [
    values.c = 1mm*display.getmmx(display.width/2);
    values.l = values.c - 10mm;
    values.r = values.c + 10mm;
]

/ trials = [1 = mytrial]
</block>

<values>
/ c = 0
/ l = 0
/ r = 0
</values>


<trial mytrial>
/ stimulusframes = [1=center, left, right]
/ validresponse = (57)
</trial>

<text center>
/ items = ("0")
/ hposition = values.c
</text>

<text left>
/ items = ("-10")
/ hposition = values.l
</text>

<text right>
/ items = ("+10")
/ hposition = values.r
</text>

+x

 

lukasg - 1/31/2022

+x

 

Dave - 1/31/2022

<block myblock>
/ onblockbegin = [
    values.c = 1mm*display.getmmx(display.width/2);
    values.l = values.c - 10mm;
    values.r = values.c + 10mm;
]

/ trials = [1 = mytrial]
</block>

<values>
/ c = 0
/ l = 0
/ r = 0
</values>


<trial mytrial>
/ stimulusframes = [1=center, left, right]
/ validresponse = (57)
</trial>

<text center>
/ items = ("0")
/ hposition = values.c
</text>

<text left>
/ items = ("-10")
/ hposition = values.l
</text>

<text right>
/ items = ("+10")
/ hposition = values.r
</text>

Great, exactly what I was looking for. I do have a follow-up question. It appears the code takes the dimensions of my primary screen (laptop). As a result, the stimuli are shifted when presenting the experiment on an external monitor. Is there a way to ensure the mm dimensions are taken from the screen that the experiment is running on?

+x

 

Dave - 1/31/2022

+x

 

lukasg - 1/31/2022

+x

 

Dave - 1/31/2022

<block myblock>
/ onblockbegin = [
    values.c = 1mm*display.getmmx(display.width/2);
    values.l = values.c - 10mm;
    values.r = values.c + 10mm;
]

/ trials = [1 = mytrial]
</block>

<values>
/ c = 0
/ l = 0
/ r = 0
</values>


<trial mytrial>
/ stimulusframes = [1=center, left, right]
/ validresponse = (57)
</trial>

<text center>
/ items = ("0")
/ hposition = values.c
</text>

<text left>
/ items = ("-10")
/ hposition = values.l
</text>

<text right>
/ items = ("+10")
/ hposition = values.r
</text>

Great, exactly what I was looking for. I do have a follow-up question. It appears the code takes the dimensions of my primary screen (laptop). As a result, the stimuli are shifted when presenting the experiment on an external monitor. Is there a way to ensure the mm dimensions are taken from the screen that the experiment is running on?

The getmmx() function allows you to specify the monitor.

https://www.millisecond.com/support/docs/v6/html/language/functions/getmmx.htm

+x

 

lukasg - 1/31/2022

+x

 

Dave - 1/31/2022

+x

 

lukasg - 1/31/2022

+x

 

Dave - 1/31/2022

<block myblock>
/ onblockbegin = [
    values.c = 1mm*display.getmmx(display.width/2);
    values.l = values.c - 10mm;
    values.r = values.c + 10mm;
]

/ trials = [1 = mytrial]
</block>

<values>
/ c = 0
/ l = 0
/ r = 0
</values>


<trial mytrial>
/ stimulusframes = [1=center, left, right]
/ validresponse = (57)
</trial>

<text center>
/ items = ("0")
/ hposition = values.c
</text>

<text left>
/ items = ("-10")
/ hposition = values.l
</text>

<text right>
/ items = ("+10")
/ hposition = values.r
</text>

Great, exactly what I was looking for. I do have a follow-up question. It appears the code takes the dimensions of my primary screen (laptop). As a result, the stimuli are shifted when presenting the experiment on an external monitor. Is there a way to ensure the mm dimensions are taken from the screen that the experiment is running on?

The getmmx() function allows you to specify the monitor.

https://www.millisecond.com/support/docs/v6/html/language/functions/getmmx.htm

But there is no way of selecting the screen the experiment is being presented on? This may be the 1st screen for some participants and the 2nd or 3rd for others?

+x

 

Dave - 1/31/2022

+x

 

lukasg - 1/31/2022

/ hposition = 1px * (display.canvaswidth/2) - 10 * expressions.ratio_pxpermm

In search for a solution I came across previous entries on absolute stimuli sizes. However, I do not see how I can translate this to the present example. The recurring issue is that display.canvaswidth and others provide the total pixel width. Thus, the physical distance in cm will differ across screens?

e.g.:

/ hposition = 1px * (display.canvaswidth/2) - 10 * expressions.ratio_pxpermm

Instead, I would two letters to presented at a horizontal distance of 2cm, for instance.

<block myblock>
/ onblockbegin = [
    values.c = 1mm*display.getmmx(display.width/2);
    values.l = values.c - 10mm;
    values.r = values.c + 10mm;
]

/ trials = [1 = mytrial]
</block>

<values>
/ c = 0
/ l = 0
/ r = 0
</values>


<trial mytrial>
/ stimulusframes = [1=center, left, right]
/ validresponse = (57)
</trial>

<text center>
/ items = ("0")
/ hposition = values.c
</text>

<text left>
/ items = ("-10")
/ hposition = values.l
</text>

<text right>
/ items = ("+10")
/ hposition = values.r
</text>

+x

 

lukasg - 2/15/2022

+x

 

Dave - 1/31/2022

+x

 

lukasg - 1/31/2022

/ hposition = 1px * (display.canvaswidth/2) - 10 * expressions.ratio_pxpermm

In search for a solution I came across previous entries on absolute stimuli sizes. However, I do not see how I can translate this to the present example. The recurring issue is that display.canvaswidth and others provide the total pixel width. Thus, the physical distance in cm will differ across screens?

e.g.:

/ hposition = 1px * (display.canvaswidth/2) - 10 * expressions.ratio_pxpermm

Instead, I would two letters to presented at a horizontal distance of 2cm, for instance.

<block myblock>
/ onblockbegin = [
    values.c = 1mm*display.getmmx(display.width/2);
    values.l = values.c - 10mm;
    values.r = values.c + 10mm;
]

/ trials = [1 = mytrial]
</block>

<values>
/ c = 0
/ l = 0
/ r = 0
</values>


<trial mytrial>
/ stimulusframes = [1=center, left, right]
/ validresponse = (57)
</trial>

<text center>
/ items = ("0")
/ hposition = values.c
</text>

<text left>
/ items = ("-10")
/ hposition = values.l
</text>

<text right>
/ items = ("+10")
/ hposition = values.r
</text>

Hello,

To obtain the physical center of the screen and place stimuli at a set distance (in mm) I have used the following code:

</values>
/ center = 0
/ left = 0
/ right = 0
</values>

<list t_x>
/ items = (values.center, values.left, values.right)
/ poolsize = 60
</list>

<list d_x>
/ items = (values.center, values.left, values.right)
/ selectionrate = always
/ not = (values.t_x)
</list>

<text t>
/ items = targets
/ select = values.t
/ hposition = values.t_x
/ txcolor = values.t_color
/ erase = false
/ fontstyle = ("Arial", 1.05cm, false, false, false, false, 5, 0)
</text>

<text d1>
/ items = distractors
/ select = values.d1
/ hposition = values.d1_x
/ txcolor = values.d1_color
/ erase = false
/ fontstyle = ("Arial", 1.05cm, false, false, false, false, 5, 0)
</text>

<text d2>
/ items = distractors
/ select = values.d2
/ hposition = values.d2_x
/ txcolor = values.d2_color
/ erase = false
/ fontstyle = ("Arial", 1.05cm, false, false, false, false, 5, 0)
</text>

<text dig1>
/ items = digits
/ select = values.dig1
/ hposition = values.center - 25mm
/ txcolor = black
/ erase = false
/ fontstyle = ("Arial", 1.05cm, false, false, false, false, 5, 0)
</text>

<text dig2>
/ items = digits
/ select = values.dig2
/ hposition = values.center + 25mm
/ txcolor = black
/ erase = false
/ fontstyle = ("Arial", 1.05cm, false, false, false, false, 5, 0)
</text>



/ onexptbegin = [
    defaults.finishpage = "INSERT PROLIFIC LINK";
    
//values.center = 1mm*display.getmmx(display.width/2);
    values.center = 1mm*display.getmmx(display.width/2,2);
values.left = values.center - 13mm;
values.right = values.center + 13mm;
]

While the rest of the experiment is displayed perfectly fine in the centre of the screen, the stimuli are displayed with an offset to the right - where do I go wrong?

+x

 

Dave - 2/15/2022

It's not possible to say based on an incomplete code snippet. My guess would be you're wrong in using display.width, and ought to use display.canvaswidth.