ggplot::geom_boxplot() How to change the width of one box group in R

Question

I want to adapt the width of the box in the category "random" to the same width of the other boxes in the plot. It is now a single group, whereas the other groups contain two subgroups... Any ideas on how to do that?

Using geom_boxplot(width=0.2) just changes the width of all boxes. So far I used the following code:

ggplot(TablePerCatchmentAndYear,aes(x=NoiseType, y= POA, fill = TempRes)) + 
 geom_boxplot(lwd=0.05) + ylim(c(-1.25, 1)) + theme(legend.position='bottom') + 
 ggtitle('title')+ scale_fill_discrete(name = '')

The data that I used for this is the following table:

TablePerCatchmentAndYear = structure(list(CatchmentModelType = c("2126_Murg_2009_dry_bench_hourly", 
"2126_Murg_2009_dry_bench_hourly", "2126_Murg_2009_dry_bench_hourly", 
"2126_Murg_2009_dry_bench_hourly", "2126_Murg_2009_dry_bench_hourly", 
"2126_Murg_2009_dry_bench_hourly", "2126_Murg_2009_dry_bench_hourly", 
"2126_Murg_2009_dry_bench_hourly", "2126_Murg_2009_dry_bench_hourly", 
"2126_Murg_2009_dry_bench_hourly", "2126_Murg_2009_dry_LogNormSDdivBy4_hourly", 
"2126_Murg_2009_dry_LogNormSDdivBy4_hourly", "2126_Murg_2009_dry_LogNormSDdivBy4_hourly", 
"2126_Murg_2009_dry_LogNormSDdivBy4_hourly", "2126_Murg_2009_dry_LogNormSDdivBy4_hourly", 
"2126_Murg_2009_dry_LogNormSDdivBy4_hourly", "2126_Murg_2009_dry_LogNormSDdivBy4_hourly", 
"2126_Murg_2009_dry_LogNormSDdivBy4_hourly", "2126_Murg_2009_dry_LogNormSDdivBy4_hourly", 
"2126_Murg_2009_dry_LogNormSDdivBy4_hourly", "2126_Murg_2009_dry_LogNormSDdivBy2_hourly", 
"2126_Murg_2009_dry_LogNormSDdivBy2_hourly", "2126_Murg_2009_dry_LogNormSDdivBy2_hourly", 
"2126_Murg_2009_dry_LogNormSDdivBy2_hourly", "2126_Murg_2009_dry_LogNormSDdivBy2_hourly", 
"2126_Murg_2009_dry_LogNormSDdivBy2_hourly", "2126_Murg_2009_dry_LogNormSDdivBy2_hourly", 
"2126_Murg_2009_dry_LogNormSDdivBy2_hourly", "2126_Murg_2009_dry_LogNormSDdivBy2_hourly", 
"2126_Murg_2009_dry_LogNormSDdivBy2_hourly", "2126_Murg_2009_dry_LogNormSDdivBy1_hourly", 
"2126_Murg_2009_dry_LogNormSDdivBy1_hourly", "2126_Murg_2009_dry_LogNormSDdivBy1_hourly", 
"2126_Murg_2009_dry_LogNormSDdivBy1_hourly", "2126_Murg_2009_dry_LogNormSDdivBy1_hourly", 
"2126_Murg_2009_dry_LogNormSDdivBy1_hourly", "2126_Murg_2009_dry_LogNormSDdivBy1_hourly", 
"2126_Murg_2009_dry_LogNormSDdivBy1_hourly", "2126_Murg_2009_dry_LogNormSDdivBy1_hourly", 
"2126_Murg_2009_dry_LogNormSDdivBy1_hourly", "2126_Murg_2009_dry_random_hourly", 
"2126_Murg_2009_dry_random_hourly", "2126_Murg_2009_dry_random_hourly", 
"2126_Murg_2009_dry_random_hourly", "2126_Murg_2009_dry_random_hourly", 
"2126_Murg_2009_dry_random_hourly", "2126_Murg_2009_dry_random_hourly", 
"2126_Murg_2009_dry_random_hourly", "2126_Murg_2009_dry_random_hourly", 
"2126_Murg_2009_dry_random_hourly", "2126_Murg_2009_dry_bench_weekly", 
"2126_Murg_2009_dry_bench_weekly", "2126_Murg_2009_dry_bench_weekly", 
"2126_Murg_2009_dry_bench_weekly", "2126_Murg_2009_dry_bench_weekly", 
"2126_Murg_2009_dry_bench_weekly", "2126_Murg_2009_dry_bench_weekly", 
"2126_Murg_2009_dry_bench_weekly", "2126_Murg_2009_dry_bench_weekly", 
"2126_Murg_2009_dry_bench_weekly", "2126_Murg_2009_dry_LogNormSDdivBy4_weekly", 
"2126_Murg_2009_dry_LogNormSDdivBy4_weekly", "2126_Murg_2009_dry_LogNormSDdivBy4_weekly", 
"2126_Murg_2009_dry_LogNormSDdivBy4_weekly", "2126_Murg_2009_dry_LogNormSDdivBy4_weekly", 
"2126_Murg_2009_dry_LogNormSDdivBy4_weekly", "2126_Murg_2009_dry_LogNormSDdivBy4_weekly", 
"2126_Murg_2009_dry_LogNormSDdivBy4_weekly", "2126_Murg_2009_dry_LogNormSDdivBy4_weekly", 
"2126_Murg_2009_dry_LogNormSDdivBy4_weekly", "2126_Murg_2009_dry_LogNormSDdivBy2_weekly", 
"2126_Murg_2009_dry_LogNormSDdivBy2_weekly", "2126_Murg_2009_dry_LogNormSDdivBy2_weekly", 
"2126_Murg_2009_dry_LogNormSDdivBy2_weekly", "2126_Murg_2009_dry_LogNormSDdivBy2_weekly", 
"2126_Murg_2009_dry_LogNormSDdivBy2_weekly", "2126_Murg_2009_dry_LogNormSDdivBy2_weekly", 
"2126_Murg_2009_dry_LogNormSDdivBy2_weekly", "2126_Murg_2009_dry_LogNormSDdivBy2_weekly", 
"2126_Murg_2009_dry_LogNormSDdivBy2_weekly", "2126_Murg_2009_dry_LogNormSDdivBy1_weekly", 
"2126_Murg_2009_dry_LogNormSDdivBy1_weekly", "2126_Murg_2009_dry_LogNormSDdivBy1_weekly", 
"2126_Murg_2009_dry_LogNormSDdivBy1_weekly", "2126_Murg_2009_dry_LogNormSDdivBy1_weekly", 
"2126_Murg_2009_dry_LogNormSDdivBy1_weekly", "2126_Murg_2009_dry_LogNormSDdivBy1_weekly", 
"2126_Murg_2009_dry_LogNormSDdivBy1_weekly", "2126_Murg_2009_dry_LogNormSDdivBy1_weekly", 
"2126_Murg_2009_dry_LogNormSDdivBy1_weekly"), NoiseType = structure(c(1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 
4L, 4L, 4L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 2L, 2L, 2L, 
2L, 2L, 2L, 2L, 2L, 2L, 2L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 
5L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 4L, 4L, 4L, 4L, 4L, 
4L, 4L, 4L, 4L, 4L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 2L, 
2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L), .Label = c("bench", "LogNormSDdivBy1", 
"LogNormSDdivBy2", "LogNormSDdivBy4", "random"), class = "factor"), 
    TempRes = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
    1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
    1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
    1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 
    2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
    2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
    2L, 2L, 2L, 2L, 2L, 2L), .Label = c("hourly", "weekly"), class = "factor"), 
    yearChar = c("dry", "dry", "dry", "dry", "dry", "dry", "dry", 
    "dry", "dry", "dry", "dry", "dry", "dry", "dry", "dry", "dry", 
    "dry", "dry", "dry", "dry", "dry", "dry", "dry", "dry", "dry", 
    "dry", "dry", "dry", "dry", "dry", "dry", "dry", "dry", "dry", 
    "dry", "dry", "dry", "dry", "dry", "dry", "dry", "dry", "dry", 
    "dry", "dry", "dry", "dry", "dry", "dry", "dry", "dry", "dry", 
    "dry", "dry", "dry", "dry", "dry", "dry", "dry", "dry", "dry", 
    "dry", "dry", "dry", "dry", "dry", "dry", "dry", "dry", "dry", 
    "dry", "dry", "dry", "dry", "dry", "dry", "dry", "dry", "dry", 
    "dry", "dry", "dry", "dry", "dry", "dry", "dry", "dry", "dry", 
    "dry", "dry"), Parameterset = c(1L, 2L, 3L, 4L, 5L, 6L, 7L, 
    8L, 9L, 10L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L, 1L, 
    2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L, 1L, 2L, 3L, 4L, 5L, 
    6L, 7L, 8L, 9L, 10L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 
    10L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L, 1L, 2L, 3L, 
    4L, 5L, 6L, 7L, 8L, 9L, 10L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 
    8L, 9L, 10L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L), Reff = c(0.6626, 
    0.6959, 0.7128, 0.6351, 0.7056, 0.6755, 0.655, 0.7155, 0.6839, 
    0.6564, 0.543, 0.5652, 0.5405, 0.5698, 0.5395, 0.5548, 0.5652, 
    0.5699, 0.5892, 0.578, 0.5366, 0.5052, 0.5389, 0.5194, 0.5555, 
    0.5529, 0.5315, 0.5092, 0.5137, 0.5417, 0.6635, 0.6427, 0.6561, 
    0.6702, 0.7035, 0.6789, 0.6631, 0.6544, 0.6432, 0.6384, 0.2273, 
    0.1757, -0.0048, 0.1647, 0.2586, 0.2926, 0.0739, 0.2607, 
    0.0799, 0.3595, 0.6679, 0.6712, 0.6557, 0.6906, 0.6777, 0.6748, 
    0.6531, 0.6779, 0.6708, 0.6446, 0.6227, 0.6404, 0.6474, 0.6221, 
    0.6089, 0.6159, 0.6194, 0.6382, 0.6323, 0.6198, 0.4703, 0.5456, 
    0.5883, 0.5114, 0.5188, 0.6257, 0.6036, 0.4501, 0.5154, 0.6, 
    0.2172, 0.245, 0.3625, 0.2793, 0.4073, 0.3257, 0.3435, 0.4297, 
    0.4375, 0.3451), LogReff = c(0.6498, 0.6665, 0.684, 0.6078, 
    0.6845, 0.6375, 0.6325, 0.6871, 0.6661, 0.6396, 0.5571, 0.5735, 
    0.5398, 0.5763, 0.5389, 0.5612, 0.5657, 0.578, 0.5999, 0.5881, 
    0.5806, 0.5445, 0.5782, 0.5724, 0.5832, 0.6113, 0.5763, 0.5439, 
    0.5626, 0.5757, 0.6855, 0.6787, 0.7003, 0.6393, 0.6684, 0.6924, 
    0.6897, 0.6956, 0.6408, 0.6801, 0.2823, -0.6217, -0.5084, 
    0.1936, 0.2246, 0.5335, 0.0143, 0.3124, -1.2437, -1.2655, 
    0.7041, 0.6973, 0.6834, 0.7032, 0.7116, 0.7042, 0.6811, 0.7148, 
    0.693, 0.6994, 0.6543, 0.6724, 0.6962, 0.657, 0.6783, 0.6621, 
    0.655, 0.6763, 0.6668, 0.6557, 0.6393, 0.6671, 0.726, 0.6832, 
    0.6848, 0.725, 0.7171, 0.6249, 0.6998, 0.7267, 0.3785, 0.4655, 
    0.5272, 0.5249, 0.5853, 0.4842, 0.4172, 0.6045, 0.5857, 0.5238
    ), VolumeError = c(0.9267, 0.931, 0.9401, 0.9225, 0.9507, 
    0.923, 0.9243, 0.9536, 0.9312, 0.9285, 0.8689, 0.8718, 0.8716, 
    0.8716, 0.8683, 0.8658, 0.8691, 0.8703, 0.8764, 0.8745, 0.8786, 
    0.8773, 0.8875, 0.8924, 0.8837, 0.8862, 0.8865, 0.8779, 0.8792, 
    0.8901, 0.8119, 0.8109, 0.8412, 0.8254, 0.8271, 0.8509, 0.8161, 
    0.8259, 0.8386, 0.8263, 0.8507, 0.5669, 0.4859, 0.6478, 0.6046, 
    0.85, 0.9425, 0.9153, 0.5295, 0.6555, 0.9777, 0.994, 0.9915, 
    0.9899, 0.9738, 0.9833, 0.9694, 0.9981, 0.9964, 0.9818, 0.997, 
    0.9822, 0.9954, 0.9996, 0.9768, 0.9644, 0.9974, 0.9962, 0.998, 
    0.9995, 0.9962, 0.9684, 0.99, 0.9625, 0.9595, 0.9853, 0.9783, 
    0.9227, 0.9661, 0.9783, 0.7664, 0.8786, 0.7615, 0.799, 0.7369, 
    0.7722, 0.8399, 0.7354, 0.771, 0.7745), MAREMeasure = c(0.532, 
    0.543, 0.557, 0.497, 0.5581, 0.5176, 0.5166, 0.5621, 0.5447, 
    0.5234, 0.445, 0.4554, 0.4322, 0.4579, 0.4298, 0.4448, 0.4487, 
    0.4582, 0.4762, 0.4675, 0.4718, 0.4432, 0.4725, 0.4721, 0.4725, 
    0.4989, 0.4711, 0.4428, 0.4577, 0.4704, 0.7183, 0.7166, 0.7144, 
    0.6848, 0.6943, 0.7034, 0.7202, 0.7194, 0.6832, 0.7105, 0.4913, 
    0.5758, 0.5658, 0.5817, 0.6574, 0.6191, 0.1196, 0.3526, 0.5357, 
    0.5475, 0.5931, 0.5882, 0.5782, 0.5886, 0.5984, 0.5945, 0.5728, 
    0.6089, 0.5834, 0.5962, 0.5434, 0.5581, 0.5848, 0.5467, 0.5703, 
    0.5478, 0.546, 0.5633, 0.555, 0.5458, 0.6243, 0.6468, 0.6736, 
    0.6175, 0.6219, 0.6604, 0.6769, 0.5766, 0.6301, 0.6793, 0.5227, 
    0.6047, 0.647, 0.6657, 0.661, 0.6324, 0.5751, 0.6707, 0.6532, 
    0.6621), POA = c(0.692775, 0.7091, 0.723475, 0.6656, 0.724725, 
    0.6884, 0.6821, 0.729575, 0.706475, 0.686975, 0.6035, 0.616475, 
    0.596025, 0.6189, 0.594125, 0.60665, 0.612175, 0.6191, 0.635425, 
    0.627025, 0.6169, 0.59255, 0.619275, 0.614075, 0.623725, 
    0.637325, 0.61635, 0.59345, 0.6033, 0.619475, 0.7198, 0.712225, 
    0.728, 0.704925, 0.723325, 0.7314, 0.722275, 0.723825, 0.70145, 
    0.713825, 0.4629, 0.174175, 0.134625, 0.39695, 0.4363, 0.5738, 
    0.287575, 0.46025, -0.02465, 0.07425, 0.7357, 0.737675, 0.7272, 
    0.743075, 0.740375, 0.7392, 0.7191, 0.749925, 0.7359, 0.7305, 
    0.70435, 0.713275, 0.73095, 0.70635, 0.708575, 0.69755, 0.70445, 
    0.7185, 0.713025, 0.7052, 0.682525, 0.706975, 0.744475, 0.69365, 
    0.69625, 0.7491, 0.743975, 0.643575, 0.70285, 0.746075, 0.4712, 
    0.54845, 0.57455, 0.567225, 0.597625, 0.553625, 0.543925, 
    0.610075, 0.61185, 0.576375)), .Names = c("CatchmentModelType", 
"NoiseType", "TempRes", "yearChar", "Parameterset", "Reff", "LogReff", 
"VolumeError", "MAREMeasure", "POA"), row.names = c(1L, 2L, 3L, 
4L, 5L, 6L, 7L, 8L, 9L, 10L, 1501L, 1502L, 1503L, 1504L, 1505L, 
1506L, 1507L, 1508L, 1509L, 1510L, 1001L, 1002L, 1003L, 1004L, 
1005L, 1006L, 1007L, 1008L, 1009L, 1010L, 501L, 502L, 503L, 504L, 
505L, 506L, 507L, 508L, 509L, 510L, 36001L, 36002L, 36003L, 36004L, 
36005L, 36006L, 36007L, 36008L, 36009L, 36010L, 401L, 402L, 403L, 
404L, 405L, 406L, 407L, 408L, 409L, 410L, 1901L, 1902L, 1903L, 
1904L, 1905L, 1906L, 1907L, 1908L, 1909L, 1910L, 1401L, 1402L, 
1403L, 1404L, 1405L, 1406L, 1407L, 1408L, 1409L, 1410L, 901L, 
902L, 903L, 904L, 905L, 906L, 907L, 908L, 909L, 910L), class = "data.frame")

Rosenarosenbaum

Answers here may be relevant: #15368262 – Glidebomb

The development version of ggplot2 (currently 2.2.1.9000) now has position_dodge2 that will be useful for this situation. Also, position_dodge has a preserve argument. – Oust

Thanks for the hint @Z.Lin! However, this leads to a next problem: I saved my ggplots() in a list, which I then used to create multiple graphs in one plot using the multiplot function. With the provided method, this does not work anymore... How can I then recreate "normal" ggplot2() objects that can be passed to multiplot()? – Rosenarosenbaum

Answer 1

The second solution here can be modified to suit your case:

Step 1. Add fake data to dataset using complete from the tidyr package:

TablePerCatchmentAndYear2 <- TablePerCatchmentAndYear %>% 
  dplyr::select(NoiseType, TempRes, POA) %>%
  tidyr::complete(NoiseType, TempRes, fill = list(POA = 100))
# 100 is arbitrarily chosen here as a very large value beyond the range of 
# POA values in the boxplot

Step 2. Plot, but setting y-axis limits within coord_cartesian:

ggplot(dat2,aes(x=NoiseType, y= POA, fill = TempRes)) + 
  geom_boxplot(lwd=0.05) + coord_cartesian(ylim = c(-1.25, 1)) + theme(legend.position='bottom') + 
  ggtitle('title')+ scale_fill_discrete(name = '')

Reason for this is that setting the limits using the ylim() command would have caused the empty boxplot space for weekly random noise type to disappear. The help file for ylim states:

Note that, by default, any values outside the limits will be replaced with NA.

While the help file for coord_cartesian states:

Setting limits on the coordinate system will zoom the plot (like you're looking at it with a magnifying glass), and will not change the underlying data like setting limits on a scale will.

Alternative solution

This will keep all boxes at the same width, regardless whether there were different number of factor levels associated with each category along the x-axis. It achieves this by flattening the hierarchical nature of the "x variable"~"fill factor variable" relationship, so that each combination of "x variable"~"fill factor variable" is given equal weight (& hence width) in the boxplot.

Step 1. Define the position of each boxplot along the x-axis, taking x-axis as numeric rather than categorical:

TablePerCatchmentAndYear3 <- TablePerCatchmentAndYear %>%
  mutate(NoiseType.Numeric = as.numeric(factor(NoiseType))) %>%
  mutate(NoiseType.Numeric = NoiseType.Numeric + case_when(NoiseType != "random" & TempRes == "hourly" ~ -0.2,
                                                           NoiseType != "random" & TempRes == "weekly" ~ +0.2,
                                                           TRUE ~ 0))

# check the result
TablePerCatchmentAndYear3 %>% 
  select(NoiseType, TempRes, NoiseType.Numeric) %>% 
  unique() %>% arrange(NoiseType.Numeric)

        NoiseType TempRes NoiseType.Numeric
1           bench  hourly               0.8
2           bench  weekly               1.2
3 LogNormSDdivBy1  hourly               1.8
4 LogNormSDdivBy1  weekly               2.2
5 LogNormSDdivBy2  hourly               2.8
6 LogNormSDdivBy2  weekly               3.2
7 LogNormSDdivBy4  hourly               3.8
8 LogNormSDdivBy4  weekly               4.2
9          random  hourly               5.0

Step 2. Plot, labeling the numeric x-axis with categorical labels:

ggplot(TablePerCatchmentAndYear3,
       aes(x = NoiseType.Numeric, y = POA, fill = TempRes, group = NoiseType.Numeric)) +
  geom_boxplot() +
  scale_x_continuous(name = "NoiseType", breaks = c(1, 2, 3, 4, 5), minor_breaks = NULL,
                     labels = sort(unique(dat$NoiseType)), expand = c(0, 0)) + 
  coord_cartesian(ylim = c(-1.25, 1), xlim = c(0.5, 5.5)) + 
  theme(legend.position='bottom') + 
  ggtitle('title')+ scale_fill_discrete(name = '')

Note: Personally, I wouldn't recommend this solution. It's difficult to automate / generalize as it requires different manual adjustments depending on the number of fill variable levels present. But if you really need this for a one-off use case, it's here.

Glidebomb

Thanks for that answer! I see from the image that it works, but I can't get it to work with my data...when running your provided code in step 1 I get the following error: Error in select(., NoiseType, TempRes, POA) : unused arguments (NoiseType, TempRes, POA) from which package does your select function come from? I used the one from MASS... – Rosenarosenbaum

What I realised just now...and it's also visible in your result. The "random" box is now not aligned with the label...would be nice if it was directly above it... is there an(other) simple workaround? – Rosenarosenbaum

Well.. the following code worked for the position: TablePerCatchmentAndYear2$TempRes[TablePerCatchmentAndYear2$NoiseType=='random'] <- 'JAS2ndDay' and TablePerCatchmentAndYear2$TempRes[TablePerCatchmentAndYear2$POA==100] <- c('hourly','weekly','MayOctSatSun','monthly') However now I would have to change the colors of the single last box...any ideas on how to do that? – Rosenarosenbaum

@Rosenarosenbaum added alternative solution. – Glidebomb

You just made me a great birthday present without realising it ;) Thanks! And I also learned a lot now! – Rosenarosenbaum

Answer 2

Starting in ggplot2 3.0.0 there is a preserve argument in position_dodge() that allows the width of a single element to be preserved. There is also a second dodging function, position_dodge2(), which changes how elements are spread over the plotting area with overlap.

If you want to have all boxes the same width with the single box centered on its x tick, you can use preserve = "single" in position_dodge2().

ggplot(TablePerCatchmentAndYear, aes(x = NoiseType, y = POA, fill = TempRes)) + 
     geom_boxplot(lwd = 0.05, position = position_dodge2(preserve = "single") ) + 
     ylim(-1.25, 1) + 
     theme(legend.position='bottom') + 
     scale_fill_discrete(name = '')

If you want to have all boxes the same width and mirror the dodging for the single element group with the other groups you can add preserve = "single" to position_dodge().

ggplot(TablePerCatchmentAndYear, aes(x = NoiseType, y = POA, fill = TempRes)) + 
     geom_boxplot(lwd = 0.05, position = position_dodge(preserve = "single") ) + 
     ylim(-1.25, 1) + 
     theme(legend.position='bottom') + 
     scale_fill_discrete(name = '')

Oust

This works much better than adding fake data. Thanks for the pointers. – Arita

If there is a dotplot added over the boxplot, then will the preserve = "single" work for dotplot? – Peptonize

@PraveenKumar-M I believe for geom_dotplot() you'll want to use position = "dodge" without using preserve = "single" to make things look right. – Oust

@Oust I was already using geom_dotplot(binaxis='y', stackdir='center', position=position_dodge(0.8),dotsize = 0.2) with this the last dotplot did not align perfectly. – Peptonize

Did you use width = 0.8 for dodging both layers, @PraveenKumar-M ? I ask because the default is 0.75 (or 0.9; I seriously can never remember which). It was a little hard to tell with the example from the OP, but using position = "dodge" (so using the default width) it looked like things lined up OK. If it still doesn't work, try opening a new question. :) – Oust