Error Discrete Value Supplied to Continuous Scale Ggplot2

ggplot2 error : Discrete value supplied to continuous scale

Solution 1

Evidently, you can't have different color aesthetics for two different geoms. As a workaround, use a fill aesthetic for the points instead. This means you have to use a point marker style that has a filled interior (see ?pch and scroll down for the available point styles). Here's a way to do that:

          ggplot() +    geom_point(data=merged,aes(x = pauseMedian, y = numTotalPauses, fill = diff),              pch=21, size=5, colour=NA) +   geom_polygon(data = splineHull,                 mapping=aes(x=pauseMedian,                             y=numTotalPauses,                             colour = microstyle),                alpha=0)

Adding colour=NA (outside of aes()), gets rid of the default black border around the point markers. If you want a colored border around the points, just change colour=NA to whatever colour you prefer.

Also see this thread from the ggplot2 Google group, discussing a similar problem and some workarounds.

Solution 2

Now that we know the two color vars are of different types, there's the issue. You can try using a different scale for one (e.g. fill instead of color)

          set.seed(123) my_df1 <- data.frame(a=rnorm(100), b=runif(100), c=rep(1:10, 10)) my_df2 <- data.frame(a=rnorm(100), b=runif(100), c=factor(rep(LETTERS[1:5], 20)))   # this won't work. can't assign discrete and continuous to same scale ggplot() +   geom_point(data=my_df1, aes(x=a, y=b, color=c)) +   geom_polygon(data=my_df2, aes(x=a, y=b, color=c), alpha=0.5)

Error: Discrete value supplied to continuous scale

          # but use fill for polygons, and that works: ggplot() +   geom_point(data=my_df1, aes(x=a, y=b, color=c)) +   geom_polygon(data=my_df2, aes(x=a, y=b, fill=c), alpha=0.5)

plot output

If you have to use the same scale (color), and can't convert the variables to the same type, see this for more info: Plotting continuous and discrete series in ggplot with facet

Solution 3

Just to add something to the preferred eipi10 answer above (thank you for that!!). The colour="NA" option in order to get rid of the border around the circle shape (pch=21) has to be between "". If you use colour=NA (without the quotation marks) the whole shape disappears and is not plotted. I would have just commented on the answer but I still don't have reputation for that :)

Comments

I have a dataset called "merged", which contains 3 numeric columns "pauseMedian" and "numTotalPauses" and "diff". I also have a splineHull dataset, which also contains numeric columns "pauseMedian" and "numTotalPauses", plus a 6-level factor "microstyle"

I have the following code, which works perfectly. It plots a scatter plop and then overlay it with splineHull polygons colored according to "microstyle".

script 1:

                  ggplot(data=merged,aes(x = pauseMedian, y = numTotalPauses))         + geom_point()          + geom_polygon(data = splineHull,                        mapping=aes(x=pauseMedian,                                    y=numTotalPauses,                                    group=microstyle,                                    color = microstyle),                        alpha=0)

Then, I also want to change the color of the points in the scatter plot by adding just one attribute color = diff.

script 2:

                  ggplot(data=merged,aes(x = pauseMedian, y = numTotalPauses, color = diff))         + geom_point()          + geom_polygon(data = splineHull,                        mapping=aes(x=pauseMedian,                                    y=numTotalPauses,                                    group=microstyle,                                    color = microstyle),                        alpha=0)

I see the following error:

Error: Discrete value supplied to continuous scale

I don't know why I see this error. If I still want colored scatter plot but no polygons, I run the following code it works again.

script 3:

                  ggplot(data=merged,aes(x = pauseMedian, y = numTotalPauses, color = diff))         + geom_point()

So, what happened with script 2, where is the error from, and how can I make it work?

Hi, I've got a very large dataset, so it's difficult to post the data here. alpha should be more than 0, but it is not the problem, and I only need to contour not filled polygon, because the plot simply does not show up due to the error. I tried your solution but I got the same error. For the color specified in geom_point, it is a numeric variable "diff", the one specified in geom_polygon is a discrete "factor". I am just guessing ggplot does not work if color attributes are assigned with different types.
Oh, well that's the key piece of missing info. See new solution
Hi, thanks. Yes it works this way. Actually I still prefer color, because I want to have just the contour (empty polygons). Anyway, this solution works for now. Thanks!
So glad to see this! I spent a long time wondering why I couldn't get it to work. Although colour = "NA" will give a white border, so if there are overlapping points/ geoms the border will still be visible.
This is great (+1), but as per Juan's answer below colour = "NA" must have quotation marks, otherwise the points will not be plotted.

Recents

penningtonriseld.blogspot.com

Source: https://9to5answer.com/ggplot2-error-discrete-value-supplied-to-continuous-scale

Error Discrete Value Supplied to Continuous Scale Ggplot2

ggplot2 error : Discrete value supplied to continuous scale

Solution 1

Solution 2

Solution 3

Related videos on Youtube

Comments

Recents

0 Response to "Error Discrete Value Supplied to Continuous Scale Ggplot2"

Enviar um comentário

Iklan Atas Artikel

Iklan Tengah Artikel 1

Iklan Tengah Artikel 2

Iklan Bawah Artikel