temp dir when plotting

[Control Systems Group]

It seems every time I use plot command, there is a temp file named 
oct-00802xea or something like that being written to the /tmp directory
on my system. The only trouble is, I only got 3M available on that 
partition. When that happens I have to either delete all those temp
files or quit octave and restart.

Are there any way to specify a directory other than /tmp to write 
those temp files to? If so, how?