HI lily,

for the colouring of individual points you can set the colour aesthetic.

The ID is numeric so ggplot applies a colour scale. If we cast ID to a

factor we get the appropriate colouring.

test_df <- data.frame(ID = 1:20, v1 = rnorm(20), v2 = rnorm(20), v3 =

rnorm(20))

ggplot(data=test_df, aes(x=v1,y=v2, colour = as.factor(ID))) +

geom_point()+ theme_bw()+

xlab('Variable 1')+ ylab('Variable 2')

How to choose a number of samples from the dataset you can use the subset

function to select by some variable:

sub_test_df1 <- subset(test_df, ID < 5)

ggplot(data=sub_test_df1, aes(x=v1,y=v2, colour = as.factor(ID))) +

geom_point()+ theme_bw()+

xlab('Variable 1')+ ylab('Variable 2')

Or sample a number of random rows using samle() if this is your intention.

sub_test_df2 <- test_df[sample(x = 1:nrow(test_df), size = 10), ]

ggplot(data=sub_test_df2, aes(x=v1,y=v2, colour = as.factor(ID))) +

geom_point()+ theme_bw()+

xlab('Variable 1')+ ylab('Variable 2')

HTH

Ulrik

On Fri, 25 Aug 2017 at 21:38 lily li <

[hidden email]> wrote:

> Hi R users,

>

> I have some sets of variables and put them into one dataframe, like in the

> following. How to choose a specific set of pareto front, such as 10 from

> the current datasets (which contains more than 100 sets)? And how to show

> the 10 points on one figure with different colors? I can put all the points

> on one figure though, and have the code below. I drew two ggplots to show

> their correlations, but I want v1 and v3 to be as close as 1, v2 to be as

> close as 0. Thanks very much.

>

> DF

>

> ID v1 v2 v3

> 1 0.8 0.1 0.7

> 2 0.85 0.3 0.6

> 3 0.9 0.21 0.7

> 4 0.95 0.22 0.8

> 5 0.9 0.3 0.7

> 6 0.8 0.4 0.76

> 7 0.9 0.3 0.77

> ...

>

> fig1 = ggplot(data=DF, aes(x=v1,y=v2))+ geom_point()+ theme_bw()+

> xlab('Variable 1')+ ylab('Variable 2')

> print(fig1)

>

> fig2 = ggplot(data=DF, aes(x=v1,y=v3)+ geom_point()+ theme_bw()+

> xlab('Variable 1')+ ylab('Variable 3')

> print(fig2)

>

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>

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>

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>

https://stat.ethz.ch/mailman/listinfo/r-help> PLEASE do read the posting guide

>

http://www.R-project.org/posting-guide.html> and provide commented, minimal, self-contained, reproducible code.

>

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______________________________________________

[hidden email] mailing list -- To UNSUBSCRIBE and more, see

https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide

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