Alternative to zip() for Pavlovia

Online experiments
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1

I wrote a long script in Python to prepare my stimuli for a study, and thought I was very clever, and now realized that at least one function—zip()—won’t work in Pavlovia. I wonder if there is a good alternative?

I will post my script as it currently exists below.

It basically takes pairs of names, shuffles them while maintaining the pairs, attaches a column of images of the appropriate gender (after these are shuffled), and a column indicating which side the names will appear on. Happy to provide more info if necessary, but I think the important question I have right now is just what to do with all of the lines of code using the zip() function.

thisExp=psychoJS.experiment;

win=psychoJS.window;
event=psychoJS.eventManager;
shuffle = util.shuffle;

Array.prototype.append = [].push;

#List of round names and spiky names
MaleNamesR = ["Abel", "Allen", "Lewis", "Linus"]
MaleNamesS = ["Eric", "Hector", "Chris", "Curtis"]

#zip them so you can shuffle while keeping pairs intact; then unzip then for later
MaleNames = list(zip(MaleNamesR, MaleNamesS))
random.shuffle(MaleNames)
MaleNamesR, MaleNamesS = zip(*MaleNames)
MaleNamesR = list(MaleNamesR)
MaleNamesS = list(MaleNamesS)

FemaleNamesR = ["Anne", "Joanna", "Noelle", "Norah"]
FemaleNamesS = ["Rita", "Erica", "Pippa", "Tessa"]

FemaleNames = list(zip(FemaleNamesR, FemaleNamesS))
random.shuffle(FemaleNames)
FemaleNamesR, FemaleNamesS = zip(*FemaleNames)
FemaleNamesR = list(FemaleNamesR)
FemaleNamesS = list(FemaleNamesS)

#Do the same thing as above but with sides of the screen
MaleSides1 = ["-.2", "-.2", ".2", ".2"]
MaleSides2 = [".2", ".2", "-.2", "-.2"] 

MaleSides = list(zip(MaleSides1, MaleSides2))
random.shuffle(MaleSides)
MaleSides1, MaleSides2 = zip(*MaleSides)
MaleSides1 = list(MaleSides1)
MaleSides2 = list(MaleSides2)

FemaleSides1 = ["-.2", "-.2", ".2", ".2"]
FemaleSides2 = [".2", ".2", "-.2", "-.2"] 

FemaleSides = list(zip(FemaleSides1, FemaleSides2))
random.shuffle(FemaleSides)
FemaleSides1, FemaleSides2 = zip(*FemaleSides)
FemaleSides1 = list(FemaleSides1)
FemaleSides2 = list(FemaleSides2)

#Prep images in the same way.
YMaleImages = ["072_y_m_n_b.jpg",
"013_y_m_n_b.jpg",
"016_y_m_n_a.jpg",
"025_y_m_n_a.jpg"] #list of young male images
OMaleImages = ["149_m_m_n_b.jpg",
"026_m_m_n_a.jpg",
"032_m_m_n_a.jpg",
"038_m_m_n_b.jpg"]
YFemaleImages = ["048_y_f_n_b.jpg",
"010_y_f_n_a.jpg",
"022_y_f_n_b.jpg",
"040_y_f_n_b.jpg"]
OFemaleImages = ["080_m_f_n_a.jpg",
"019_m_f_n_b.jpg",
"029_m_f_n_b.jpg",
"043_m_f_n_a.jpg"]

shuffle(YMaleImages)
shuffle(OMaleImages)
shuffle(YFemaleImages)
shuffle(OFemaleImages)

YMaleImages_A = YMaleImages[0:2] #take just the top half of the random young male images
YMaleImages_B = YMaleImages[2:4]

OMaleImages_A = OMaleImages[0:2]
OMaleImages_B = OMaleImages[2:4]

YFemaleImages_A = YFemaleImages[0:2]
YFemaleImages_B = YFemaleImages[2:4]

OFemaleImages_A = OFemaleImages[0:2]
OFemaleImages_B = OFemaleImages[2:4]

Males1 = YMaleImages_A + OMaleImages_A 
Males2 = YMaleImages_B + OMaleImages_B

c = list(zip(Males1, Males2))
random.shuffle(c)
Males1, Males2 = zip(*c)
Males1 = list(Males1)
Males2 = list(Males2)

Females1 = YMaleImages_A + OMaleImages_A 
Females2 = YMaleImages_B + OMaleImages_B

c = list(zip(Females1, Females2))
random.shuffle(c)
Females1, Females2 = zip(*c)
Females1 = list(Females1)
Females2 = list(Females2)

#Put different stimuli together into columns
NamesR = MaleNamesR + FemaleNamesR
NamesS = MaleNamesS + FemaleNamesS
Sides1 = MaleSides1 + FemaleSides1
Sides2 = MaleSides2 + FemaleSides2
Images1 = Males1 + Females1
Images2 = Males2 + Females2

#shuffle the columns 
AllTrials = list(zip(NamesR, NamesS, Sides1, Sides2, Images1, Images2))
random.shuffle(AllTrials)
NamesR, NamesS, Sides1, Sides2, Images1, Images2 = zip(*AllTrials)

NamesR = list(NamesR)
NamesS = list(NamesS)
Sides1 = list(Sides1)
Sides2 = list(Sides2)
Images1 = list(Images1)
Images2 = list(Images2)

AllTrials = [NamesR, NamesS, Sides1, Sides2, Images1, Images2]
2

Try putting the following code in a JS only code component in Begin Experiment

zip = function zip() {
    var args = [].slice.call(arguments);
    var shortest = args.length==0 ? [] : args.reduce(function(a,b){
        return a.length<b.length ? a : b
    });

    return shortest.map(function(_,i){
        return args.map(function(array){return array[i]})
    });
}

I got this from Javascript equivalent of Python's zip function - Stack Overflow

If the arrays are unequal length then this version should silently ignore the extra bits of the longer ones.

3

Thanks for the reply. However, I’m getting the following error.

Screen Shot 2022-06-14 at 12.07.35 PM

4

I’ve had a look at your code and the zip function was working fine.

The problem was matrix addition.

Instead of Males1 = YMaleImages_A + OMaleImages_A you need to use Males1 = YMaleImages_A.concat(OMaleImages_A)

The zip function was failing because the arguments were incorrect.

Also you were using AllTrials[trials.thisN,2] instead of AllTrials[2][trials.thisN] to address items in two dimensional arrays.

5

Thank you! It is now running smoothly!!

Though now I have to figure out why my images aren’t showing up… But this seems to be a separate problem because 1) if I just name a static image it also doesn’t show up, and 2) I’m not getting a resource not found error.

Edit: Nevermind, for some reason I’m now getting this error:

Screen Shot 2022-06-16 at 1.04.23 PM

I have this getting defined on the LoadJobs routine.