CODEWITHSUNDEEP
rggplot2
Capt.Krusty
Capt.Krusty

Reputation: 627

Colouring of datapoint with ggplot2 and RColorBrewer

I have got a df with over 400 datapoints and want to colour those accourding to the RColorBrewer package with the palette = "Blues".

I plotted my data and even expanded the color input maximum of the palette to the length of my data points to avoid getting "Error messages" (see below), but the colors in the plot aren't changing (only a black line).

Error: Aesthetics must be either length 1 or the same as the data (427): fill

I've created a dummy df to make my problem reproducible:

library(ggplot2)
library(RColorBrewer) 

color = colorRampPalette(rev(brewer.pal(n = 9, name = "Blues")))(300)

df = (curve(3*x^2 + x, from=1, to=10, n=300, xlab="xvalue", ylab="yvalue", 
         col="blue", lwd=2, main="Plot of (3x^2 + x)"))
dfx = matrix(data = df$x, ncol = 1)
dfy = matrix(data = df$y, ncol = 1)
dfa = cbind(dfx,dfy)

DF = ggplot(dfa, aes(x = dfx, y = dfy)) +
      geom_point(fill = color)

I expect the curve to change into a light blue at the start (1,4) with an increase in darkness till the end (dark blue at the end (10,310)).

Thanks in advance!

Upvotes: 0

Views: 410

Answers (2)

Carlos Eduardo Lagosta
Carlos Eduardo Lagosta

Reputation: 1001

exDF <- data.frame(dataX = seq(1, 10, .1),
                   dataY = sapply(seq(1, 10, .1), function(x) 3*x^2 + x))

exDFcolors <- colorRampPalette(brewer.pal(9, "Blues"))(nrow(exDF))

ggplot(exDF, aes(dataX, dataY)) +
  geom_line(size = 2, color = exDFcolors)

enter image description here

Upvotes: 1

Pablo Rod
Pablo Rod

Reputation: 669

color_seq = colorRampPalette(brewer.pal(n = 9, name = "Blues"))(300)

df = (curve(3*x^2 + x, from=1, to=10, n=300, xlab="xvalue", ylab="yvalue", 
            col="blue", lwd=2, main="Plot of (3x^2 + x)"))
dfx = matrix(data = df$x, ncol = 1)
dfy = matrix(data = df$y, ncol = 1)
dfa = as.data.frame(cbind(dfx , dfy, color_seq), stringsAsFactors = FALSE)

dfa$V1 <- as.numeric(dfa$V1)  ## convert both to numeric so the scale is continous
dfa$V2 <- as.numeric(dfa$V2)

ggplot(dfa, aes(x = V1, y = V2, color = color_seq)) +
  geom_point() +
  scale_color_identity()

Upvotes: 2

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