[R] Problem in graph plotting

[FMH]

Dear All,

Let:
dp: depth of the river 
tp: temperature with respect to depth

We can have a simple scatter plot, between depth as y-axis and temperature as x-axis, by using a plot function as shown below.

##################### 
dp <- c(1,4,3,2,5,7,9,8,9,2)
tp <- 1:10
plot(tp,dp, type= 'l')
#####################
 
Could someone advice me on the way to plot the same pair of observations, but with depth in descending order from the origin. Instead of depth, I tried to simply use rev(depth), but the result was bizarre.
 
Thank you
Fir