R ggplot limiting dates on plot x-axis

Question

I'm trying to create a chart with volume on y-axis and app week on x-axis. However, plotting using ggplot results in a misalignment on my chart. I've researched proposed solutions by tweaking limits and the expand functions but still can't seem to get the desired outcome.

Below is my code to generate the chart:

min_date = min(Data2$Week)
max_date = max(Data2$Week)

lims = c(min_date,max_date)

a = {Data2 %>%
    mutate(facet=ifelse(ChartGroup=='Test1','Test','Control')) %>%
    ggplot(aes(x=Week, y=Volume, group=ChartGroup, color=ChartGroup)) + 
    geom_line() + geom_point() + facet_grid(facet~.,scales='free_y') +
    theme( axis.text.x = element_text(angle = 90)) +
    labs(title="Volume") + 
    labs(x= "Week") + 
    labs(y ="Volume") +
    scale_x_date(breaks=date_breaks("week"),
                 labels = date_format("%Y-%m-%d"),
                 limits=lims,
                 expand = c(0,0))}

Here's some sample data:

structure(list(ChartGroup = c("Test1", "Test1", "Test1", "Test1", 
"Test1", "Test1", "Test1", "Test1", "Test1", "Test1", "Test1", 
"Test1", "Test1", "Test1", "Test1", "Test1", "Test1", "Test1", 
"Test1", "Test1", "Test1", "Test1", "Test1", "Test1", "Test1", 
"Test", "Test", "Test", "Test", "Test", "Test", "Test", "Test", 
"Test", "Test", "Test", "Test", "Test", "Test", "Test", "Test", 
"Test", "Test", "Test", "Test", "Test", "Test", "Test", "Test", 
"Test", "Test", "Test", "Test", "Test", "Test", "Test", "Test", 
"Test", "Test", "Test", "Test", "Test", "Test", "Test", "Test", 
"Test", "Test", "Test", "Test", "Test", "Test", "Test", "Test", 
"Test", "Test"), Week = c("12/28/2017", "1/4/2018", "1/11/2018", 
"1/18/2018", "1/25/2018", "2/1/2018", "2/8/2018", "2/15/2018", 
"2/22/2018", "3/1/2018", "3/8/2018", "3/15/2018", "3/22/2018", 
"3/29/2018", "4/5/2018", "4/12/2018", "4/19/2018", "4/26/2018", 
"5/3/2018", "5/10/2018", "5/17/2018", "5/24/2018", "5/31/2018", 
"6/7/2018", "6/14/2018", "12/28/2017", "12/28/2017", "1/4/2018", 
"1/4/2018", "1/11/2018", "1/11/2018", "1/18/2018", "1/18/2018", 
"1/25/2018", "1/25/2018", "2/1/2018", "2/1/2018", "2/8/2018", 
"2/8/2018", "2/15/2018", "2/15/2018", "2/22/2018", "2/22/2018", 
"3/1/2018", "3/1/2018", "3/8/2018", "3/8/2018", "3/15/2018", 
"3/15/2018", "3/22/2018", "3/22/2018", "3/29/2018", "3/29/2018", 
"4/5/2018", "4/5/2018", "4/12/2018", "4/12/2018", "4/19/2018", 
"4/19/2018", "4/26/2018", "4/26/2018", "5/3/2018", "5/3/2018", 
"5/10/2018", "5/10/2018", "5/17/2018", "5/17/2018", "5/24/2018", 
"5/24/2018", "5/31/2018", "5/31/2018", "6/7/2018", "6/7/2018", 
"6/14/2018", "6/14/2018"), Volume = c(273.0894758, 885.410888, 
1123.424761, 940.204851, 1015.8218, 1595.801905, 167.8867937, 
792.0141589, 915.0446468, 2307.141323, 2277.582562, 1303.148027, 
1987.675449, 189.8547385, 102.8398224, 1122.591571, 615.5550876, 
1123.017699, 1680.158398, 2023.198433, 1206.52614, 1935.904725, 
1028.85108, 2259.716499, 1820.035456, 6748.379814, 19263.34329, 
20263.55385, 8616.685352, 36268.79244, 8369.983757, 46668.11793, 
15634.93125, 25826.72827, 15203.71984, 11781.08351, 14527.59158, 
45597.59167, 7459.457733, 46060.49379, 19793.76319, 58165.58381, 
18497.82931, 48976.75836, 35195.1871, 32711.4056, 51272.6735, 
17267.50781, 38880.17827, 31562.78799, 15184.4221, 33993.32688, 
27081.21869, 53983.76112, 38520.25106, 49381.99962, 4233.203344, 
2556.980954, 8367.881436, 15473.37447, 21542.29983, 35065.2121, 
26370.52407, 7564.324054, 9969.176408, 50594.20126, 14232.09825, 
38125.67594, 36392.11016, 15048.03106, 25569.13761, 1464.704752, 
25366.02593, 25365.96216, 236.938689)), class = "data.frame", row.names = c(NA, 
-75L))

Below is the resulting chart. Min date is 12-28-2017 and max date is 06-14-2018. However, the axis labels do not start or end on those days.

Resulting image of chart on R:

Can you please post some sample data to reproduce the problem? Copy/pasteable sample data is best - you can use `dput()` to share a subset of your data. [See this tutorial for additional tips on creating reproducible examples in R](https://stackoverflow.com/q/5963269/903061). — Gregor Thomas, Jun 22 '18 at 01:44
If I were to guess just based on your code, I would say the problem is that you set your limits based on a column called `Week`, but your x values are from a column called `Dateweek`, and it looks like the `Dateweek` range is wider than the `Week` range. But without seeing data, that's just a guess. I would also guess that `expand = c(0, 0)` is hurting rather than helping your goal. — Gregor Thomas, Jun 22 '18 at 01:46
That was just a typo. I've made the edit so that it reflects the correct thing but it wasn't the source of my error. — takeaseat123, Jun 22 '18 at 15:30

phalteman · Accepted Answer · 2018-06-22T22:27:07.880

Two main fixes here. First is that your column Week is not recognized as a date, so fix that first:

Data2$Week <- as.Date(Data2$Week, format="%m/%d/%Y")

Second, arguments in scale_x_date() weren't quite right. Revised plotting code below should get you what you're looking for.

ggplot(a, aes(x=Week, y=Volume, group=ChartGroup, color=ChartGroup)) + 
  geom_line() + 
  geom_point() + 
  facet_grid(facet~.,scales='free_y') +
  theme(axis.text.x = element_text(angle = 90)) +
  labs(title="Volume") + 
  labs(x= "Week") + 
  labs(y ="Volume") +
  scale_x_date(breaks = seq(as.Date(lims[1]), as.Date(lims[2]), by="1 week"), date_labels = "%Y-%m-%d")

R ggplot limiting dates on plot x-axis

1 Answers1