How to plot my aggregated trajectories using mousetrap in R

Comments

• Pascal

  February 2022

  Hi Sara,

  could you share the complete code for preprocessing, i.e., including the part where you align the trajectories and the code you use for plotting? Also, you were writing "align start and finish" above in which case you would not have to do the subsequent remapping. If you only align at the start and not at the end, a remapping would make sense.

  Another comment, just from a first visual impression of the plot: it looks to me as if your trajectories are upside down, i.e., they are aligned at the start (in the top left) and then travel towards the bottom right (and actually deviate towards the unchosen option which would then be in the bottom left). This is often the case if trajectories are not remapped as in many software packages (e.g., in OpenSesame) raw y values increase as the cursor moves down (and not as it moves up).

  Best,

  Pascal
• TheViuf

  February 2022

  Importing the data

  raw <- mt_import_mousetrap(
    df,
    xpos_label = "xpos",
    ypos_label = "ypos",
    timestamps_label = "timestamps")
  

  Including only yes-responses

  raw <- mt_subset(raw,answer=="Yes")
  

  Time normalizing

  raw_remapped <- mt_time_normalize(raw)
  

  
  

  Align start and end coordinates.

  raw_remapped <- mt_align_start_end(raw_remapped,
            use = "tn_trajectories",
            save_as = "use",
            dimensions = c("xpos", "ypos"),
            start = c(0,0),
            end = c(-1,1),
            verbose = FALSE)
  

  Remapping to left side of the screen,

  raw_remapped <- mt_remap_symmetric(
   raw_remapped,
   use = "tn_trajectories",
   save_as = "tn_trajectories",
   dimensions = c("xpos", "ypos"),
   remap_xpos = "left",
   remap_ypos = "no"
  )
  

  
  

  When I ran through it and left out the last step of remapping it looked like this:

  I use this to plot

  aggregated <- mt_plot_aggregate(raw_remapped, use="tn_trajectories",
   color="condition") + ggtitle("Aggregated trajectories") + theme_minimal() 
  
      
  
          
              
          
      
  
  

  If I use the non time normalized data in mt_plot_aggregate specified in "use=tracejtories" it looks like this

  

  Ahh, I see how it's upside down. How do I fix that?

  
  

  Sara
• Pascal

  February 2022

  Hi Sara,

  I think there are some minor issues with some of your code snippets above:

  raw_remapped <- mt_align_start_end(raw_remapped,
            use = "tn_trajectories",
            save_as = "use",
            dimensions = c("xpos", "ypos"),
            start = c(0,0),
            end = c(-1,1),
            verbose = FALSE)
  

  In the code above setting save_as to "use" with quotation marks does not work as it will then store the start-end-aligned trajectories actually in the "use" element. You could just leave this line out and then the start-end-aligned trajectories are stored in "tn_trajectories":

  raw_remapped <- mt_align_start_end(raw_remapped,
            use = "tn_trajectories",
            dimensions = c("xpos", "ypos"),
            start = c(0,0),
            end = c(-1,1),
            verbose = FALSE)
  

  I also don't think it makes sense to do both mt_align_start_end and mt_remap_symmetric (as the remapping will implicitly be done by mt_align_start_end). However, it could make sense to not use mt_align_start_end and instead use mt_align_start only and then mt_remap_symmetric afterwards and specify remap_ypos to "up", e.g., like this:

  # Time normalize trajectories (as was done above)
  raw_remapped <- mt_time_normalize(raw)
  
  # Align start positions
  raw_remapped <- mt_align_start(raw_remapped,
            use = "tn_trajectories",
            dimensions = c("xpos", "ypos"),
            start = c(0,0),
            verbose = FALSE)
  
  # Remap trajectories
  raw_remapped <- mt_remap_symmetric(
   raw_remapped,
   use = "tn_trajectories",
   dimensions = c("xpos", "ypos"),
   remap_xpos = "left",
   remap_ypos = "up"
  )
  
  

  Best,

  Pascal