CODEWITHSUNDEEP
rggplot2dplyr
user8248672
user8248672

Reputation:

Reorder factor not working on grouped data

I have this dataframe that I call top_mesh_terms 

structure(list(topic = c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L), term = c("Diabetes Mellitus", 
"Depression", "Syndrome", "Diabetes Mellitus, Type 2", "Lung Diseases", 
"Colorectal Neoplasms", "Osteoarthritis", "Sclerosis", "Lymphoma", 
"Lung Diseases, Obstructive", "Diabetes Mellitus", "Disease", 
"Hypertension", "Syndrome", "Carcinoma", "Infection", "Coronary Disease", 
"Lung Neoplasms", "Obesity", "Infarction"), beta = c(0.0196989252285569, 
0.018472562347772, 0.0175512616261399, 0.0146680780420432, 0.0133507951269683, 
0.01224603797061, 0.0116799262133244, 0.0107893497000735, 0.00926496950657875, 
0.00891926541108836, 0.0324598963852768, 0.0198135918084849, 
0.0162689075944415, 0.0157166860189554, 0.014855885836076, 0.0127365678034364, 
0.0109544570325732, 0.00964124158432716, 0.00956596829604797, 
0.00880281359338067)), class = c("tbl_df", "tbl", "data.frame"
), row.names = c(NA, -20L))

As the title suggests, I'd like to reorder the term column by beta and then draw a bar chart. I hoped to see a bar chart with ordered bars, but that is not the case. Here is the code I used and the resulting graph:

top_mesh_terms %>% 
  group_by(topic) %>% 
  mutate(term = fct_reorder(term, beta)) %>%
  ungroup() %>% 
  ggplot(aes(term, beta)) +
  geom_bar(stat = "identity") +
  facet_wrap(~ topic, scales = "free") +
  coord_flip() +
  scale_y_continuous(labels = scales::percent_format()) +
  labs(x = "MeSH Term",
       y = "Beta")

enter image description here

Upvotes: 1

Views: 2181

Answers (2)

Gregor Thomas
Gregor Thomas

Reputation: 145775

Your problem is the group_by. The levels of a factor have a single order, it can't differ by group. If we get rid of your group_by and ungroup commands, everything works:

    top_mesh_terms %>% 
      mutate(term = reorder(term, beta)) %>%
      ggplot(aes(term, beta)) +
      geom_bar(stat = "identity") +
      facet_wrap(~ topic, scales = "free") +
      coord_flip() +
      scale_y_continuous(labels = scales::percent_format()) +
      labs(x = "MeSH Term",
           y = "Beta")

enter image description here

(Btw, forcats has some really nice functions, but if the only one you need is fct_reorder you might as well use base::reorder - it does the same thing without the extra package dependency.)

Upvotes: 3

william3031
william3031

Reputation: 1708

How about this?

top_mesh_terms %>% 
  group_by(topic) %>% 
  mutate(term = fct_reorder(term, beta)) %>%
  ungroup() %>% 
  ggplot(aes(reorder(term, beta), beta)) +
  geom_bar(stat = "identity") +
  facet_wrap(~ topic, scales = "free") +
  coord_flip() +
  scale_y_continuous(labels = scales::percent_format()) +
  labs(x = "MeSH Term",
       y = "Beta")

I used the ggplot(aes(reorder(term, beta) to change the order.

Upvotes: 1

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