I am making a geom_col in ggplot2. The x-axis is a numerical vector of timepoints (0, 6, 18, 24, 32, 44). There is a difference between each column corresponding to the numerical difference between each timepoint. But i want an equal distance between all the columns. I have searched for answers in here, but i didn't find a similar issue.
This is my code:
ggplot(data = ny_dataframe_scratch, aes(x=timepoint, y = relative_wound_healing, fill = Condition)) +
geom_col(width = 5, position = position_dodge()) +
scale_x_continuous(breaks=c(0, 6, 18, 24, 32, 44), name = "Time point, hours") +
scale_y_continuous(name = "Relative scratch area") +
scale_fill_manual(values=c("palevioletred4", "slategray")) +
geom_point(data = ny_dataframe_scratch, position = position_dodge(width = 5), aes(x=timepoint, y=relative_wound_healing, fill = Condition))
This is the output of dput():
structure(list(timepoint = c(0, 0, 0, 0, 0, 0, 6, 6, 6, 6, 6,
6, 18, 18, 18, 18, 18, 18, 24, 24, 24, 24, 24, 24, 32, 32, 32,
32, 32, 32, 44, 44, 44, 44, 44, 44), Condition = structure(c(2L,
2L, 2L, 1L, 1L, 1L, 2L, 2L, 2L, 1L, 1L, 1L, 2L, 2L, 2L, 1L, 1L,
1L, 2L, 2L, 2L, 1L, 1L, 1L, 2L, 2L, 2L, 1L, 1L, 1L, 2L, 2L, 2L,
1L, 1L, 1L), .Label = c("Control", "Knockout"), class = "factor"),
relative_wound_healing = c(1, 1, 1, 1, 1, 1, 0.819981, 0.78227,
0.811902, 0.873852, 0.893572, 0.910596, 0.39819, 0.436948,
0.559486, 0.534719, 0.591295, 0.612154, 0.222731, 0.2592,
0.453575, 0.37238, 0.477891, 0.505393, 0.05243246, 0.0809449,
0.2108063, 0.261122, 0.3750218, 0.4129873, 0, 0.0240122,
0.0778219, 0.0806758, 0.2495444, 0.3203724)), class = "data.frame", row.names = c(NA,
-36L))
Picture of how the graph looks:
The x-scale has proportional gaps because ‘ggplot2’ considers the values as continuous rather than categorical.
To make it categorical, you can for instance use factors:
aes(x = factor(timepoint, ordered = TRUE), …
(Without ordered = TRUE
, ‘ggplot2’ assumes alphabetical ordering, so it would put 11
before 5
, which probably isn’t what you want.)
To fix the bar heights, you need to compute and plot a summary statistic — ‘ggplot2’ allows you to do this using stat_summary
(instead of geom_col
):
stat_summary(fun.y = mean, geom = "col", position = position_dodge())
Taken together:
ggplot(ny_dataframe_scratch) +
aes(x = factor(timepoint, ordered = TRUE), y = relative_wound_healing, fill = Condition) +
scale_fill_manual(values = c("palevioletred4", "slategray")) +
stat_summary(fun.y = mean, geom = "col", position = position_dodge()) +
geom_point(position = position_dodge(width = 1)) +
labs(x = "Time point, hours", y = "Relative scratch area")