Regression tree size in the context of state sequence analysis using TraMineR in R

Question

I am conducting a regression tree using state sequence analysis and I want the image output to have the dimensions of a Letter size paper (landscape).

When I use the code I include the regression tree appears as a separate window, always of the same size, and the actual file in my computer is empty. I have to "Save as" the window that pops in order to get the regression tree, but the size is even (width, height). I would appreciate any help:

st_tk <- seqtree(tk.seq ~  Gender + age_groups + race_eth + Paying_rec + Marital + 
                           Education_rec + Pop + Employment_rec + Housing + Criminal + 
                           alcohol + cocaine + cannabis + meth + benzo + diff_opioid + 
                           opioid_route + sum_comor + site,
                 data = df_seq_tree, 
                 R = 5000, 
                 diss = dist.dhd,
                 weight.permutation = "diss",
                 max.depth = 10,
                 pval = 0.05)

# Save the regression tree as a PNG image
png("Output/Takehome/Reg_tree/st_tk.png", width = 11, height = 8.5)
seqtreedisplay(st_tk, type = "d", border = NA, image.format = "png", gvpath = 'C:/Program Files/Graphviz',
               cex.main = 2)
dev.off()

Thanks in advance!

Answer 1

Unfortunately, I am not aware of any simple way to do it. The function seqtreedisplay uses graphviz and not the R graphic engine to produce the image. Therefore, calling png() does not have any effect.

in order to have more control, you need to call dot (the graphviz program) by yourself. This will allow you to change everything in the plot.

To do so, you can use the function seqtree2dot, which will generate the dot file as well as all required image.

seqtree2dot(st_tk, filename="mytree", type = "d", border = NA, cex.main = 2)

You can then modify the dot file to suit your needs. Finally, you can generate the image using graphviz/dot.