Adding a trend line to a series of box plots

#1
If this is so obvious everyone should know I apologize for the inconvenience. I would like to add a color coded trend line to a series of box plots (graph attached)..

Any help is much appreciated..

The code I have used for the graph is as follows:
Code:
boxplot(total1$y~total1$x)
The data looks like this but its probably not necessary..

Code:
$x
 [1] -13.0000000 -12.6530612 -12.3061224 -11.9591837 -11.6122449 -11.2653061 -10.9183673
 [8] -10.5714286 -10.2244898  -9.8775510  -9.5306122  -9.1836735  -8.8367347  -8.4897959
[15]  -8.1428571  -7.7959184  -7.4489796  -7.1020408  -6.7551020  -6.4081633  -6.0612245
[22]  -5.7142857  -5.3673469  -5.0204082  -4.6734694  -4.3265306  -3.9795918  -3.6326531
[29]  -3.2857143  -2.9387755  -2.5918367  -2.2448980  -1.8979592  -1.5510204  -1.2040816
[36]  -0.8571429  -0.5102041  -0.1632653   0.1836735   0.5306122   0.8775510   1.2244898
[43]   1.5714286   1.9183673   2.2653061   2.6122449   2.9591837   3.3061224   3.6530612
[50]   4.0000000

$y
 [1] 0.16425213 0.16446394 0.16483380 0.16452690 0.16452727 0.16545171 0.16683403 0.16820805
 [9] 0.16910761 0.16906651 0.16761859 0.16429766 0.16005747 0.16069792 0.15871489 0.14826989
[17] 0.13951012 0.13193516 0.12348524 0.11484289 0.10889779 0.10604680 0.10335454 0.10178520
[25] 0.10062285 0.09830493 0.09527004 0.09173088 0.08774875 0.08346114 0.07805828 0.07153300
[33] 0.06456116 0.05845316 0.05288977 0.04751710 0.04490921 0.04311034 0.04032817 0.04014305
[41] 0.04028394 0.03872037 0.03788178 0.03785863 0.03843549 0.03939690 0.04052744 0.04161167
[49] 0.04243414 0.04277942
 

bugman

Super Moderator
#3
What are these data?

Boxplots are more suited to data that are arranged by catergory. Your plot is showing points (a new "boxplot") for each xy pair and are essentially meaningless.
 
#4
OK.. I see what you mean, this data has been averaged out so there is no range.. I am still a work in progress understanding stats..

I should just plot the data with a different function and can see the same pattern. Back to work.. :)