susie_plot file_prefix doesn't work

[koujiaodahan]

I try to run susie_plot(fitted_rss1,y="PIP",b=sumread$V9,file_prefix="./test")
get the warning:
Warning messages:
1: In plot.window(...) : "file_prefix" is not a graphical parameter
2: In plot.xy(xy, type, ...) : "file_prefix" is not a graphical parameter
3: In axis(side = side, at = at, labels = labels, ...) :
"file_prefix" is not a graphical parameter
4: In axis(side = side, at = at, labels = labels, ...) :
"file_prefix" is not a graphical parameter
5: In box(...) : "file_prefix" is not a graphical parameter
6: In title(...) : "file_prefix" is not a graphical parameter

and I didn't see the output in the specified directory

[pcarbo]

From what I can tell, file_prefix is only an input argument for susie_plot_iteration.