Package DiagrammeR in R has a nice Razor-like string replacement syntax using @@ for node labels.
In simple unidirectional flowcharts I made in the past using digraph flowchart, I used to be able to combine it with an additional sprintf() statement to insert numbers from a table.
However, I cannot make it work with a newer complex flowchart with side arms based on dummy nodes that is based on this answer. Here is a minimal reproducible example.
library(DiagrammeR)
inclusion_flowchart <- grViz(
sprintf("digraph flowchart {
# node definitions with substituted label text
node [fontname = Helvetica, shape = rectangle]
base [label = '@@1']
exc1 [label = '@@2']
rem1 [label = '@@3']
exc2 [label = '@@4']
rem2 [label = '@@5']
exc3 [label = '@@6']
rem3 [label = '@@7']
exc4 [label = '@@8']
rem4 [label = '@@9']
# downward arrows FROM dummy nodes where a side arrow starts
node [shape=none, width=0, height=0, label = '']
side1 -> rem1;
side2 -> rem2;
side3 -> rem3;
side4 -> rem4;
# side arrows from dummy nodes
{rank = same; side1 -> exc1}
{rank = same; side2 -> exc2}
{rank = same; side3 -> exc3}
{rank = same; side4 -> exc4}
# downword LINES TO dummy sites where a side arrow starts
edge [dir = none]
base -> side1;
rem1 -> side2;
rem2 -> side3;
rem3 -> side4;
}
[1]: 'Included patients with baseline data: n=%s participants'
[2]: 'Excluded for reason 1: n=%s'
[3]: 'Remain after exclusion 1: n=%s'
[4]: 'Excluded for reason 2: n=%s'
[5]: 'Remain after exclusion 2: n=%s'
[6]: 'Excluded for reason 3: n=%s'
[7]: 'Remain after reason 3: n=%s'
[8]: 'Excluded for reason 4: n=%s'
[9]: 'Remain after reason 4: n=%s'
",
100, #1, could be extracted from a table
10, #2, could be extracted from a table
90, #3, could be extracted from a table
25, #4, could be extracted from a table
65, #5, could be extracted from a table
4, #6, could be extracted from a table
61, #7, could be extracted from a table
17, #8, could be extracted from a table
44 #9, could be extracted from a table
) # closes sprintf
) # closes grViz call
But I obtain the following error message, which obviously refers to the Razor-like replacement:
Error in gsub(paste0("@@", i), eval_expressions[[i]][1], spec_body) :
invalid 'replacement' argument
I have tried enclosing the sprintf() statement in replace_in_spec(), which is used explicitly in the documentation of DiagrammeR, but this was not necessary in my previous use of this structure in simpler flowcharts (unfortunately, I cannot retrieve those examples), and leads to the same error.
I suspect there is something wrong with my node specifications, but I cannot identify the problem. Note that if I strip the syntax from any attempt to replace substrings I do obtain the desired structure:
inclusion_flowchart_naked <- grViz("digraph flowchart {
# node definitions with substituted label text
node [fontname = Helvetica, shape = rectangle]
base [label = 'base']
exc1 [label = 'exc1']
rem1 [label = 'rem1']
exc2 [label = 'exc2']
rem2 [label = 'rem2']
exc3 [label = 'exc3']
rem3 [label = 'rem3']
exc4 [label = 'exc4']
rem4 [label = 'rem4']
# downward arrows FROM dummy nodes where a side arrow starts
node [shape=none, width=0, height=0, label = '']
side1 -> rem1;
side2 -> rem2;
side3 -> rem3;
side4 -> rem4;
# side arrows from dummy nodes
{rank = same; side1 -> exc1}
{rank = same; side2 -> exc2}
{rank = same; side3 -> exc3}
{rank = same; side4 -> exc4}
# downword LINES TO dummy sites where a side arrow starts
edge [dir = none]
base -> side1;
rem1 -> side2;
rem2 -> side3;
rem3 -> side4;
}
") # closes grViz call
Which is:
Thank you in advance if you can share your ideas. I am using R 3.6.2, RStudio 1.2.5033, and DiagrammeR 1.0.5.
