在GGPLOT2散點圖更改色彩

Question

我試圖修改一些現有的代碼，原來是在這裏（https://stats.stackexchange.com/questions/76999/simulating-longitudinal-lognormal-data-in-r）中發現的問題，並用在以下網站展示R中的散點圖：https://hopstat.wordpress.com/2014/10/30/my-commonly-done-ggplot2-graphs/

這是一個簡單和愚蠢的問題，但我整個上午一直在努力。下面的代碼給出了一個很好的黑白分佈圖。我想修改代碼以使線條非常淺灰色。

library(MASS) 
library(nlme) 
library(plyr) 
library(ggplot2) 

### set number of individuals 
n <- 200 

### average intercept and slope 
beta0 <- 1.0 
beta1 <- 6.0 

### true autocorrelation 
ar.val <- .4 

### true error SD, intercept SD, slope SD, and intercept-slope cor 
sigma <- 1.5 
tau0 <- 2.5 
tau1 <- 2.0 
tau01 <- 0.3 

### maximum number of possible observations 
m <- 10 

### simulate number of observations for each individual 
p <- round(runif(n,4,m)) 

### simulate observation moments (assume everybody has 1st obs) 
obs <- unlist(sapply(p, function(x) c(1, sort(sample(2:m, x-1, 
replace=FALSE))))) 

### set up data frame 
dat <- data.frame(id=rep(1:n, times=p), obs=obs) 

### simulate (correlated) random effects for intercepts and slopes 
mu <- c(0,0) 
S <- matrix(c(1, tau01, tau01, 1), nrow=2) 
tau <- c(tau0, tau1) 
S <- diag(tau) %*% S %*% diag(tau) 
U <- mvrnorm(n, mu=mu, Sigma=S) 

### simulate AR(1) errors and then the actual outcomes 
dat$eij <- unlist(sapply(p, function(x) arima.sim(model=list(ar=ar.val), 
n=x) * sqrt(1-ar.val^2) * sigma)) 
dat$yij <- (beta0 + rep(U[,1], times=p)) + (beta1 + rep(U[,2], times=p)) *  
log(dat$obs) + dat$eij 

dat = ddply(dat, .(id), function(x){ 
    x$alpha = ifelse(runif(n = 1) > 0.9, 1, 0.1) 
    x$grouper = factor(rbinom(n=1, size =3 ,prob=0.5), levels=0:3) 
    x 
}) 
tspag = ggplot(dat, aes(x=obs, y=yij)) + 
    geom_line() + guides(colour=FALSE) + xlab("Observation Time Point") + 
    ylab("Y") 
spag = tspag + aes(colour = factor(id)) 
spag 
bwspag = tspag + aes(group=factor(id)) 
bwspag 

我已經試過scale_colour_manual，我已經試過定義在bwspag線...沒有運氣的AES語句中的顏色。我對R相對缺乏經驗。我很感激任何幫助！

Answer 1

是否要在灰度級中設置行？如果是的話，那麼colour中geom_line()的功能應該足夠了。例如：

ggplot(iris, aes(Sepal.Length, Sepal.Width)) + geom_line(colour = "gray40") 

您可以選擇其他值與灰：從0到100 More info here.