no image should be loaded for "?" in list

[Tobi]

Hi together,

I have a problem as fallows: I have a display containing n positions
as specified in the "slide element". Which bitmap is supposed to be
placed on which position is then defined in a list. Sometimes, I wish
to have no bitmap at all on some positions. Therefore I left the "?"
in the list. An error message occurs saying "Filename or image display
has not been set". It is the same if I leave a blank in the respective
cell.

I also thought about displaying en empty bitmap (that is in the color
of the background), however the positions are superimposed. Therefore,
te bitmaps would only be partly displayed.

Maybe there is an easy solution, I didn't find any.
Thanks a lot and cheers,
Tobi

[liwenna]

How about.....

adding an attribute to your list that holds the number of bitmaps that
you need to use in that level/trail called say... "nbitmaps" and give
the slide element multiple states that are called 1 2 3 4 etc. and
hold 1 2 3 or 4 images. Then set the slidestate to [nbitmaps] and
according to the value of 'nbitmaps' it will show the slidestate with
1 2 3 or 4 imageobjects in it. As a consequence you might also need to
specify the x and y values (positions) of each imageobject in the
triallist instead of in the properties of each imageobject (as I think
you got them now?). I am not entirely sure if e-prime will allow the
slideobject to run if not all referenced values for all slidestates
are being adressed in the triallist (as would be the case for say
slidestate 4 in a nbitmap = 3 trial) but you can give it a shot; and
also, depending on your actually number of possible positions, this
might be not a feasible option... but yeah... it's just a suggestion.

Alternatively you might be able to solve it somehow by drawing the
entire canvas for each trial in an inline but that definitly is a lot
of work.

Then there is a vague notion somewhere in my head that you can bring
imageobjects to the front or sent them to the back... but I have no
friggin clue as to how to do that 'dynamically' based on each trial's
demands....

That would be all for the moment ...

best,

liw

[Tobi]

Thank a lot,

it is a good idea with the different slide states. Actually there is
always only one object displayed, so I don't need to specify the
number. However, I can only make up to 10 slide states apparently. As
I have 14 different locations I would need 14, though...
Is there a way to have more than 10?

[liwenna]

Oooh, if I understand you right now, that changes the whole story!

There's only 1 object per trial but there are 14 possible positions?
In that case you'd be better of defining the positions in a list.

As you know the imageobject asks for a value for x and y on the
propertiestab to determine the position. You can also store these
values in a list under two attributes called, for intance, stimx and
stimy.
In the object properties tab enter [stimx] and [stimy] as the values
for x and y and for each trial the slidelocation will be subtracted
from the list.
If you want a certain object to be in a specific location on each run
you should create 'stimx' and 'stimy' in the same list as your
imageobjects are defined in, but if you want the positions to be
randomized on each trial, stick 'stimx' and 'stimy' in a seperate
(randomized) positionslist that is nested in the triallist.

I hope that the above is indeed what you need!

Greets,

liw

[David McFarlane]

Tobi,

Just another thought to throw into the mix... What if you made an
"empty" bitmap with a transparent background color? There are some
tricks to doing this, you have to fool around with stuff like "Use
Source Color Key" and "Source Color Key". I don't have a lot of
experience with this myself, but if you search online with those
sorts of terms, or look at the ImageDisplay.SourceColorKey topic in
the online E-Basic Help, you might get some ideas.

-- David McFarlane, Professional Faultfinder

[Michiel Spape]

Oops, read on and saw that the OP already had this covered - in which case I would refer to David's reply below!
Sorry about the confusion,
Mich

Michiel Spapé
Research Fellow
Perception & Action group
University of Nottingham
School of Psychology

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[Michiel Spape]

Hi,
Sorry if this has been said before, but just to make sure: I'm a real fan of just going to ms-paint and making a blank (white, or whatever other bg colour you use) picture of exactly the same size as the other images. Due to the BMP specifications, it should take your pc exactly as long as any of the other pictures to load etc, so you can be very sure the timing will not be different for producing blank images (they being images themselves).
It's basically the same trick I use if I want to see the effect of moving vs static images on slides (you know, with a little loop and a counter and all that); instead of not-moving the images, I just keep moving to the same location, so that the timing is not altered.
Cheers,

Mich

Michiel Spapé
Research Fellow
Perception & Action group
University of Nottingham
School of Psychology


-----Original Message-----
From: e-p...@googlegroups.com [mailto:e-p...@googlegroups.com] On Behalf Of David McFarlane
Sent: 06 November 2009 14:29
To: e-p...@googlegroups.com
Subject: Re: no image should be loaded for "?" in list

[Tobi]

Thanks for your help!

I used liwenna's suggestion and it works really fine (thanks for
that!). The timing should't be a problem as there is always the same
number of stimuli on the screen, only the x- und y-coordinates change.

Cheers,
Tobi

On 6 Nov., 15:57, Michiel Spape <Michiel.Sp...@nottingham.ac.uk>
wrote: