Home > Net >  NetworkD3 sankey chart in R creating really messy links, even though my code should be good. What is
NetworkD3 sankey chart in R creating really messy links, even though my code should be good. What is

Time:06-17

I am trying to create a sankey diagram but the connections turn out all messed up. Here is my data:

#> A tibble: 61 x 3
#> # Groups:   id_2 [55]
#>     id_2 origin                target                     
#>    <int> <fct>                 <chr>                      
#>  1     4 Pendlerkort i app     Rejsekort                  
#>  2    38 Ungdomskort           Rejsekort                  
#>  3    84 Rejsekort             Rejsekort                  
#>  4    89 Rejsekort             Pendlerkort i app          
#>  5    95 Rejsekort             Rejsekort                  
#>  6   112 Rejsekort Pendlerkort Rejsekort                  
#>  7   118 Pendler20             Rejsekort med pendler kombi
#>  8   140 Pendlerkort i app     Rejsekort                  
#>  9   167 DSB Orange            Pendler20                  
#> 10   193 Rejsekort             Rejsekort                  
#> # ... with 51 more rows

sankey_plot <- 
  tibble::tribble(
    ~id_2,  ~origin,                  ~target,
    4L,     "Pendlerkort i app",      "Rejsekort",
    38L,    "Ungdomskort",            "Rejsekort",
    84L,    "Rejsekort",              "Rejsekort",
    89L,    "Rejsekort",              "Pendlerkort i app",
    95L,    "Rejsekort",              "Rejsekort",
    112L,   "Rejsekort Pendlerkort",  "Rejsekort"
  )

Then I run the following code:

# create nodes
nodes <- data.frame(
  name=c(as.character(sankey_plot$origin),
         as.character(sankey_plot$target)) %>% unique()
)

# Get values  
sankey_plot <- sankey_plot %>% group_by(origin, target) %>% 
  summarise(values = n())

sankey_plot <- sankey_plot %>% 
  dplyr::ungroup()

# Create source and target ID's
sankey_plot$IDsource <- match(sankey_plot$origin, nodes$name)-1 
sankey_plot$IDtarget <- match(sankey_plot$target, nodes$name)-1

# Plot
sankeyNetwork(Links = sankey_plot, Nodes = nodes,
              Source = "IDsource", Target = "IDtarget",
              Value = "values",
              NodeID = "name",
              # fontSize = 10 
              nodeWidth = 20,
              sinksRight = TRUE)

This gives me a messy plot looking like this:

Messy sankey plot

I have no idea what I am doing wrong. I have tried to create the nodes in a few different ways. Also where I don't group_by() and simply let each row represent each movement (instead of having a count). The plot ends up looking the same

CodePudding user response:

Given the sample data you provided, the loops are expected. For instance, line 3 represents a link that starts and ends at the same node, and line 1 represents a link from a node ("Pendlerkort I app") that follows the "Rejsekort" node and then links back to the "Rejsekort" node again.

sankey_plot
#> # A tibble: 5 × 5
#>   origin                target            values IDsource IDtarget
#>   <fct>                 <chr>              <int>    <dbl>    <dbl>
#> 1 Pendlerkort i app     Rejsekort              1        0        2
#> 2 Rejsekort             Pendlerkort i app      1        2        0
#> 3 Rejsekort             Rejsekort              2        2        2
#> 4 Rejsekort Pendlerkort Rejsekort              1        3        2
#> 5 Ungdomskort           Rejsekort              1        1        2

enter image description here

If what you're expecting is that there are different nodes that all have the same name "Rejsekort", then you will have to distinguish those nodes in your data.

library(dplyr)
library(networkD3)


sankey_plot <- 
  tibble::tribble(
  ~id_2,  ~origin,                  ~target,
  4L,     "Pendlerkort i app",      "Rejsekort",
  38L,    "Ungdomskort",            "Rejsekort",
  84L,    "Rejsekort",              "Rejsekort",
  89L,    "Rejsekort",              "Pendlerkort i app",
  95L,    "Rejsekort",              "Rejsekort",
  112L,   "Rejsekort Pendlerkort",  "Rejsekort"
)

dupe_targets <- sankey_plot$target == "Rejsekort"
sankey_plot$target[dupe_targets] <-
  paste0(sankey_plot$target[dupe_targets], "_", seq_along(sankey_plot$target[dupe_targets]))

sankey_plot$values <- 1

# create nodes
nodes <- data.frame(
  name=c(as.character(sankey_plot$origin),
         as.character(sankey_plot$target)) %>% unique()
)

# Create source and target ID's
sankey_plot$IDsource <- match(sankey_plot$origin, nodes$name)-1 
sankey_plot$IDtarget <- match(sankey_plot$target, nodes$name)-1


sankey_plot
#> # A tibble: 6 × 6
#>    id_2 origin                target            values IDsource IDtarget
#>   <int> <chr>                 <chr>              <dbl>    <dbl>    <dbl>
#> 1     4 Pendlerkort i app     Rejsekort_1            1        0        4
#> 2    38 Ungdomskort           Rejsekort_2            1        1        5
#> 3    84 Rejsekort             Rejsekort_3            1        2        6
#> 4    89 Rejsekort             Pendlerkort i app      1        2        0
#> 5    95 Rejsekort             Rejsekort_4            1        2        7
#> 6   112 Rejsekort Pendlerkort Rejsekort_5            1        3        8


sankeyNetwork(Links = sankey_plot, Nodes = nodes,
              Source = "IDsource", Target = "IDtarget",
              Value = "values",
              NodeID = "name",
              # fontSize = 10 
              nodeWidth = 20,
              sinksRight = TRUE)

enter image description here

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