绘制固定的绘图区域

Question

I have simple question, how can I plot fixed height barplots, ie stretching the plot area only change margins not the bararea, like the following:

> A <- 4
> plot (A)

> barplot(A, col = "green4")

When I strech are, bar area also get increases.

Edits: I want to keep the box size constant even the plot gets stretched.

Answer 1

by splitting the screen into multiple parts, you can achieve that partially:

split.screen(c(3,1))
A <- 4
barplot(A, col="green4")

Answer 2

Are you looking to just expand the y axis. Look at ylim ?

Answer 3

What you might be looking for is to fix your aspect ratio. This can be achieved using asp :

barplot(A, col = "green4", asp = 1)

See also this post to R-help .

On a more philosophical note, when the height of the bar changes, there is no change in surface area. barplot only draws a sequence of bars, where the x axis is an ordinal (ordered categorical) variable which makes it impossible to calculate a surface area. The height of the bar is the only changing variable. I would recommend drawing these kinds of timeseries using a simple line plot.

So instead of:

a = runif(100)
b = 1:100
barplot(a)

use:

plot(b, a, type = "l")

or switch to my favorite plotting package, ggplot2 :

require(ggplot2)
theme_set(theme_bw())
qplot(b, a, geom = "line")