ggplot2 R，在轴上固定很多值（线图）

Question

I can't read my y-axis since is has a lot of values. I tried rotating it and it doesn't work like I want, neither is it something I want to do.

I want to specify the values in the axis, to be from say 20 to 30, maybe with step 0.1.

But the length of the values are 1000, so I guess the range suggested above doesn't work (?). Ex:

runNumbers <- seq(from = 1, to = 1000)
tempVector <- seq(from = 20.0010, to = 30, by = 0.01) 
plotData   <- data.frame(RunNumber = runNumbers, temp = tempVector,
myUglyPlot <- ggplot(data = plotData, mapping = aes(x = RunNumber, y = temp, group = 1)) +      geom_line() 
#
#http://stackoverflow.com/questions/14428887/overflowing-x-axis-ggplot2?noredirect=1&lq=1 
require(scales) # for removing scientific notation
# manually generate breaks/labels
labels                   <- seq(from = 0, to = 30, length.out = 1000)
# and set breaks and labels    
myUglyPlot <- myUglyPlot + scale_y_discrete(breaks = labels, labels = as.character(labels))
# And now my graph is without labels, why?

Is there another way to do this, without rotating my labels? Or am I doing something wrong in the code from the other question (I tried to follow what he did...)?

Later I will have 10 000 values instead, so I really need to change this, I want to have a readable axis, that I can put the interval in.

Maybe I'm missing in some simple concept, I tried to search and read R Graphics Cookbook, but without success for now.

Thanks for your time.

Update Im trying to use breaks, thanks for the help guys. Here's what I'm doing now (only this):

myUglyPlot   <- ggplot(data = plotData, mapping = aes(x = RunNo, y = t_amb, group = 1)) + geom_line()
myUglyPlot   <- myUglyPlot + scale_y_discrete(breaks=seq(from = 1, to = 50, by = 0.01))

But my it doesn't give me any breaks. See pic.

Answer 1

您几乎要在那里了。由于y轴是一个连续值，因此需要使用scale_y_continuous而不是scale_y_discrete 。

myUglyPlot <- myUglyPlot + scale_y_continuous(breaks = labels)