Getting a text message to move slightly (ideally in Sketchpad)

Stroller

I'm a newby to OS. However, your tutorials have really helped me get going. Needless to say I'm trying to keep the coding as simple as possible. Is there an easy way to get a piece of text in Sketchpad move / animate slightly without embedding videos. I need it as it part of an experiment to see what is the best stimulus for peripheral alerts.

Thanks

lvanderlinden

Hi @Stroller,

Thanks for your interest in OpenSesame and in the tutorials, and welcome to the forum! :)

If you exclusively want to use the graphical user interface, I think you could do the following:

• Append a nested loop-sequence structure to your trial_sequence
• Define all possible x and y locations of the text in the new loop item. The smaller you make the steps between the subsequent positions, the smoother the animation will be. (In the example I made steps of 10 pixels, which is not very smooth)
• Make sure you set the order of this new loop item to "sequential" instead of "random"

I uploaded an example here:

6919.osexp

However, because there are limits to the number of (x,y) combinations that you manually can/want to define in the block_loop, having a little bit of inline code to determine the x and y positions gives you much more freedom and flexibility.

If the latter is what you want, then please let us know whether you want to run your study locally (in which case we'll use Python inline scripting) or in the browser (which requires JavaScript code).

Hope this helps!

Cheers,

Lotje

Stroller

Hi Lotje

Fantastic. I'll give it a try. I'm running the study locally.

Kind Regards

Stroller

lvanderlinden

Hi @Stroller , ok, great! Let us know if you want to go for the inline-script option.

Stroller

Hi @lvanderlinden . It works pretty well. However, I would be interested in seeing the inline-script option (if you have time) to see if it improves the experiment and also as a learning point for me.

Thanks

Stroller

lvanderlinden

Hi @Stroller ,

With Python inline script, you could do the following:

• Append a Python inline_script item to the beginning of your trial_sequence and put something like the following in its Prepare tab (see comments for further explanation):

# Import the library numpy
import numpy as np

# Define properties of the list of x and y positions:
# (By preceeding the variable names with the .var
# notation, we make sure that they are recognized in the interface
# and logged by the logger item)
var.x_start = 0 # first x coordinate
var.x_end = 300 # last x coordinate

var.y_start = 0
var.y_end = 300

# Define the number of steps
# The higher, the smoother, but also
# the higher, the slower
# (Max is the length of the lists of coordinates)
var.n_steps = 100

# Define list of x positions by using the np
# function linspace()
list_x_pos = list(np.linspace(var.x_start, var.x_end, var.n_steps))

# List of y positions:
list_y_pos = list(np.linspace(var.y_start, var.y_end, var.n_steps))

# Reverse the lists
# (So that we can use the pop() function in the trial sequence)
list_x_pos = list_x_pos[::-1]
list_y_pos = list_y_pos[::-1]

• Append another inline_script item to the sequence item that is embedded in the trial_sequence (which I called "move_sequence" in the example). In the Prepare tab, define the current x and y positions like so:

var.x_pos = list_x_pos.pop()
var.y_pos = list_y_pos.pop()

• Finally, to give the nested loop (here "move_loop") the appropriate length, you need to tweak the OpenSesame script (not to be confused with Python script) of this item a little bit. To do that: click on View script (where my cursor is in the screenshot below) and change the line setting the repeat value to the variable "n_steps" as defined in the first inline_script item, like so:

set repeat "[n_steps]"

I uploaded an example file.

6919_2.osexp

Let me know if this helps!

Cheers,

Lotje

Stroller

Hi Lotje, Thanks for all your help. I was really strugling. I have learnt a lot from your help. It's worked perfectly

lvanderlinden

Thank you so much for the coffee! :)