Shading between lines in ggplot

Question

I have a data set, and I am able to plot the data set fine, however, I have three lines on my graph and I want to shade between them (So two shading regions).

    ZNH2<-structure(list(value = c("154.102123376241", "129.342971722961", 
"59.214424508985", NA, "79.7543253228812", "56.9720749846859", 
"147.904588068996", "127.832589574989", "41.9504584377476", "30.210899339716", 
"189.915069536722", "206.470143151635", "269.431758501289", "330.519022331884", 
"80.9548026764334", "135.275345151106", "70.8898624532545", "333.065088493364", 
"245.671050594358", "217.694093154847", "202.293931253186", "320.08224840969", 
"152.675949949667", "85.6197139863922", "71.1857213343614", "222.044301846973", 
"111.437578615948", "991.558657706669", "77.5176101480006", "90.3789552959655", 
"117.223606151342", "44.9530550879222", "167.092674420099", "175.107272805158", 
"196.46944973477", "154.071757533894", "118.28502485382", "122.756078599527", 
"79.8304508785081", "226.840582406991", "119.065146684801", "170.225407520687", 
"177.651665865621", "175.597432999921", "104.179544790707", NA, 
NA, NA, NA, NA, NA, NA, NA, "16.8437034171218", "21.589296969022", 
"21.5293178756595", NA, "17.1577492347234", "15.9453880616562", 
"45.8596992672078", "44.8514087972185", "24.0627701288669", "130.128455156461", 
"72.9531584398895", "34.6680166210599", "68.0830269285413", "45.5857868971278", 
"34.962220142646", "149.522794107249", "43.5106817194628", "80.1849936102008", 
"50.1407523335261", "25.7103931548188", "51.707257838463", "56.514058394911", 
"47.697772888689", "65.17156146864", "20.165819163686", "92.7341148329014", 
"62.2774860245454", "187.079350368038", "41.5562639058451", "28.8978603742495", 
"41.1724906723211", "5.77878944647918", "56.0880422383573", "68.4731748377562", 
"74.0245489658521", "44.7719649917539", "15.1070354391827", NA, 
NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, "0", 
"0", "0", NA, "0", NA, "0.061935327", NA, "0.238451009", "0.006193533", 
"0", "0", "0.015483832", "0", NA, "0.390192559", "0.300386335", 
"0.105290056", "0", NA, "0.015483832", "0", "0.191999513", "0.151741551", 
"0.09290299", "0.021677364", "0", "0", "0.086709458", "0", "0", 
"0", NA, NA, NA, "0.021677364", NA, "0", "0", NA, "0", "0", "0", 
NA, "0.030750948", "0.00615019", "0", "0", "0", "0", "0", "0", 
"0", "0.018450569", "0", "0", "0", "0", NA, "0.017852517", "0", 
NA, NA, NA, "0", NA, "0", "0.014648219", NA, "0", "0.017852517", 
"0.008239623", NA, "0.017852517", "0", "0.021056815", "0.005035325", 
"0.030669709", "0.027465411", "0.043486901", "0.017852517", "0.005035325", 
"0.024261113", "0", "0", "0.001831027", "0.014648219", "0", "0.017852517", 
"0.037078305", NA, NA, NA, "0.027465411", NA, "0.008239623", 
"0.046691199", "0.088347072", "0.011443921", "0.008239623", "0.033874007", 
NA, "0.037078305", "0.011443921", "0.014648219", "0", "0.024261113", 
"0.005035325", "0.005035325", "0.296626438", "0.053099794", "0.017852517", 
"0.040282603", "0.001831027", "0", "0", NA, "0.004881939", NA, 
"0.011095317", "0.032842138", "0.042162204", "0.017308694", "0.032842138", 
"0.014202006", NA, "0.00183211", "0", "0.033894034", "0.046718803", 
"0.011450687", "0.040306418", "0.037100226", "0.017863072", "0.030687841", 
"0", "0", "0.00183211", "0", "0", NA, "0.007988628", "0.091869224", 
NA, NA, NA, "0.024275457", "0.00183211", NA, NA, NA, "0", NA, 
"0", "0", NA, "0", "0", "0", NA, "0.005038302", "0", "0.242296538", 
"0", "0", "0", "0", "0", "0.033894034", "0.00183211", "0.005038302", 
"0.017863072", "0.030687841", "0", "0.153675746", NA, "0.020562248", 
"0.007575565", "0.008657789", "0.011904459", "0.001082224", "0.006493341", 
"0.011904459", "0.006493341", "0.018397801", "0.010822236", "0.017315577", 
"0.011904459", "0.020562248", "0.041124495", NA, NA, NA, "0.014068906", 
"0.067097861", "0.004328894", "0.006493341", "0.002164447", "0.038960048", 
"0.020562248", "0.019480024", NA, NA, "1.311886266", NA, "2.046087257", 
"2.139996686", "0.295956988", "1.343189409", "2.088773361", "2.029012815", 
"1.579385852", "1.272045902", "1.6676038", "0.130904053", "1.838348217", 
"2.003401153", "2.066007439", "2.108693543", "2.677841597", "2.071698919", 
"2.048932997", NA, NA, NA, "0.700052107", NA, "0.017074442", 
"0.073989247", NA, "1.072844083", "1.109838707", "0.093156627", 
NA, "0.069599779", NA, NA, "0.048184462", "0.103864285", "0.099581222", 
"0.098510456", "0.091015095", "0", "0.014990722", "0.18738402", 
"0.244134608", "0.301955963", "0.239851545", NA, "0.085661266", 
NA, "0.01284919", "0", NA, "0.029981443", "0.005353829", "0.67458247", 
"0.033193741", "0.032122975", NA, NA, NA, NA, "0.012553306", 
NA, NA, NA, NA, NA, "0", "0.028244939", "0.034521592", "0.059628204", 
NA, "0.056489878", "0.028244939", "0.062766531", NA, "0.018829959", 
NA, "0.003138327", NA, NA, "0.028244939", "0", "0.382875839", 
"0.009221717", NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, "0", 
"0", "0", "0", NA, "0", NA, NA, NA, "0.003073906", NA, "0", "0", 
NA, "0.015369529", "0", NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, 
NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, 
NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, 
NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, 
NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, "2", "1"), 
    `Sample type` = c("K2SO4_18", "K2SO4_18", "K2SO4_18", "K2SO4_18", 
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    "K2SO4_18", "K2SO4_18", "K2SO4_18", "K2SO4_18", "K2SO4_18", 
    "K2SO4_18", "K2SO4_18", "K2SO4_18", "K2SO4_18", "K2SO4_18", 
    "K2SO4_18", "K2SO4_18", "K2SO4_18", "K2SO4_18", "K2SO4_18", 
    "K2SO4_18", "K2SO4_18", "K2SO4_18", "K2SO4_18", "K2SO4_18", 
    "K2SO4_18", "K2SO4_18", "K2SO4_18", "K2SO4_18", "H2O_18", 
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    17718, 17718, 17718, 17718, 17718, 17718, 17718, 17726, 17726, 
    17726, 17726, 17726, 17726, 17726, 17726, 17726, 17726, 17726, 
    17726, 17726, 17726, 17726, 17726, 17726, 17726, 17726, 17726, 
    17726, 17726, 17726, 17726, 17726, 17726, 17726, 17726, 17726, 
    17732, 17732, 17732, 17732, 17732, 17732, 17732, 17732, 17732, 
    17732, 17732, 17732, 17732, 17732, 17732, 17732, 17732, 17732, 
    17732, 17732, 17732, 17735, 17735, 17735, 17735, 17735, 17735, 
    17735, 17735, 17740, 17740, 17740, 17740, 17740, 17740, 17740, 
    17740, 17740, 17740, 17740, 17740, 17740, 17740, 17740, 17740, 
    17740, 17740, 17740, 17740, 17740, 17740, 17740, 17740, 17740, 
    17740, 17740, 17740, 17740, 17747, 17747, 17747, 17747, 17747, 
    17747, 17747, 17747, 17747, 17747, 17747, 17747, 17747, 17747, 
    17747, 17747, 17747, 17747, 17747, 17747, 17747, 17747, 17747, 
    17747, 17747, 17747, 17747, 17747, 17747, 17752, 17752, 17752, 
    17752, 17752, 17752, 17752, 17752, 17752, 17752, 17752, 17752, 
    17752, 17752, 17752, 17752, 17752, 17752, 17752, 17752, 17752, 
    17752, 17752, 17752, 17752, 17752, 17752, 17752, 17752, 17759, 
    17759, 17759, 17759, 17759, 17759, 17759, 17759, 17759, 17759, 
    17759, 17759, 17759, 17759, 17759, 17759, 17759, 17759, 17759, 
    17759, 17759, 17759, 17759, 17759, 17759, 17759, 17759, 17759, 
    17759, 17763, 17763, 17763, 17763, 17763, 17763, 17763, 17763, 
    17767, 17767, 17767, 17767, 17767, 17767, 17767, 17767, 17767, 
    17767, 17767, 17767, 17767, 17767, 17767, 17767, 17767, 17767, 
    17767, 17767, 17767, 17767, 17767, 17767, 17767, 17767, 17767, 
    17767, 17767, NA, NA), class = "Date")), .Names = c("value", 
"Sample type", "Z", "Date2"), class = "data.frame", row.names = c(NA, 
-493L))

I use the below code to make a graph:

 p<-ggplot(ZNH2, aes(ZNH2$Date2,ZNH2$value,color=ZNH2$`Sample type`, na.rm=T))+
  stat_summary(fun.y = mean,geom = "point",lwd=6) +
  stat_summary(fun.y = mean,geom = "line",lwd=2) +
  stat_summary(fun.data = mean_se, geom = "errorbar", lwd=1.5, width = 1)

When attempting to add the shaded regions I am having issues because each line has variable lengths of data and no matter how I have tried to set this up I receive error messages. I've tried using geom_rect, geom_polygon, geom_ribbon, and several others. I could use help on how to set up any function capable of shading within ggplot.

The below image is the graph that I currently have. attempting to shade between Green and red, red and blue, as well as blue and x-axis all in different colors

image 1: attempting to shade between Green and red, red and blue, as well as blue and x-axis all in different colors image 2: This image shows current graphs after shading, the issue is that I get two different shades of the green due to layering. How can I tell ggplot to shade between data sets and not all the way to y=0

Your image didn't upload correctly - can you fix it so we have a better idea of what you're trying to achieve? — iod
Use geom_ribbon for shading areas. I would also strongly recommend doing your data manipulation before plotting, using dplyr or data.table, rather than trying to force a graphics package like ggplot to do your data manipulation inside stat_summary. stat_summary is great for quick little stuff, but for anything more complicated it's more straightforward to separate those two pieces of work. — Gregor Thomas
the "character string" error is because you're giving the dates in as.Date() in dmy format instead of ymd (e.g. 2018-6-4). — iod
@iod am unable to post pictures, if possible recreate using the code or follow the link. the character string fix definitely doesn't fix anything. — Kyle
@Gregor, This is the only way the error bars come out. I think ggplot should be capable of taking simple means and SE? doing this before ggplot causes many issues. Note that this is not my raw data set but a well-manicured set of columns that I formed to make this graph. How would I set up geom_ribbon to do this, I can't get this function to do anything I want in this context. — Kyle

Gregor Thomas Gregor Thomas · Accepted Answer · 2018-10-25T17:01:22

It seems like you want an area chart. This is the name of a chart that shades between a line and the axis, and by ordering the factors correctly with the highest values layered "underneath" the lowest values.

As a side-note, never use $ inside aes, it's probably the root of a lot of your problems here. Whenever you use $ you're forcing the entire column vector, overriding any grouping that might be going on (by facet, by x, by color...). Using unquoted column names allows ggplot to do it's own manipulation of sub-data frames.

 library(dplyr)
 agg_data = ZNH2 %>%
   mutate(Type = `Sample type`, value = as.numeric(value)) %>% 
   group_by(Date2, Type) %>%
   summarize(mean_value = mean(value, na.rm = TRUE),
             se = sqrt(var(value, na.rm = TRUE) / sum(!is.na(value)))) %>%
   filter(Type != "id.vars") %>%
   ungroup() %>%
   mutate(Type = factor(Type),
          Type = reorder(Type, -mean_value, na.rm = TRUE))

ggplot(agg_data, aes(x = Date2, y = mean_value, fill = Type)) +
  geom_area(position = 'identity', alpha = 0.4) +
  geom_line(aes(color = Type), lwd = 1) +
  geom_errorbar(aes(ymin = mean_value - se, ymax = mean_value + se, color = Type), lwd = 0.7, width = 1) +
  geom_point(shape = 21)

Shading between lines in ggplot

1 Answers