help installing gnuplot

Dear Darwin Ports,

I'm new to DarwinPorts and need some help installing gnuplot onto my new MacBook
(OS 10.4.7). The machine is brand new, I've only used setup assistant to
transfer files from my old computer to this one.

I used the .pkg file and installed DarwinPorts successfully.
In Terminal, at the command line I tried

> sudo port install gnuplot

Here's what came out:

--->  Fetching aquaterm
--->  Attempting to fetch aquaterm_src.1.0.0.tar.gz from
http://easynews.dl.sourceforge.net/aquaterm
--->  Verifying checksum(s) for aquaterm
--->  Extracting aquaterm
--->  Configuring aquaterm
--->  Building aquaterm with target -buildstyle Deployment -target AquaTerm
Error: Target com.apple.build returned: can't read "build.cmd": Neither pbxbuild
nor xcodebuild were found on this system!
Error: The following dependencies failed to build: aquaterm gd2 freetype zlib
jpeg libpng pdflib readline
Error: Status 1 encountered during processing.


I have no idea what this means or how to fix it/get around it. Any help would be
greatly appreciated!

Cheers,
Joyce