diff cpack/dml/api/r_plot.pl @ 0:718306e29690 tip

commiting public release

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cpack/dml/api/r_plot.pl	Tue Feb 09 21:05:06 2016 +0100
@@ -0,0 +1,103 @@
+/* Part of DML (Digital Music Laboratory)
+	Copyright 2014-2015 Samer Abdallah, University of London
+	 
+	This program is free software; you can redistribute it and/or
+	modify it under the terms of the GNU General Public License
+	as published by the Free Software Foundation; either version 2
+	of the License, or (at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public
+	License along with this library; if not, write to the Free Software
+	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+:- module(api_r_plot, []).
+
+:- use_module(library(http/http_dispatch)).
+:- use_module(library(http/http_parameters)).
+:- use_module(library(sandbox)).
+:- use_module(library(insist)).
+:- use_module(library(fileutils)).
+:- use_module(library(swipe)).
+:- use_module(library(httpfiles)).
+:- use_module(library(real)).
+
+:- set_prolog_flag(double_quotes,string).
+:- set_prolog_flag(back_quotes,symbol_char).
+
+:- http_handler(api(r/render), r_figure_render, []).
+
+:- setting(r_plot:pixels_per_inch,number,150,"Pixels per inch for in browser figures").
+:- setting(r_plot:default_figure_format,oneof([png,svg]),svg,"Default R figure rendering method").
+
+%% figure_render(+Request) is det.
+%
+%  HTTP handler for rendering R figures.
+r_figure_render(Request) :-
+   setting(r_plot:pixels_per_inch,DefPPI),
+   http_parameters(Request,
+      [ code(CodeA,[ atom, optional(false), description("Prolog rendering goal")])
+      , format(F, [ oneof([eps,svg,pdf,png]), optional(false), description("Output format") ]) 
+      , width(W,  [ number, optional(true), default(10), description("Width in cm")])
+      , height(H, [ number, optional(true), default(6), description("Height in cm")])
+      , font_name(FN,  [ atom, optional(true), default(helvetica) ])
+      , font_size(FS,  [ number, optional(true), default(10) ])
+      , ppi(PPI,       [ number, optional(true), default(DefPPI), description("PNG resolution")])
+      ]),
+   debug(r_plot,"Attempting to parse \"~s\".",[CodeA]),
+   read_term_from_atom(CodeA,Code,[]),
+   (  user_db:logged_on(A)
+   -> debug(r_plot,"Logged on as ~w, no checking",[A])
+   ;  debug(r_plot,"Checking ~q for safety...",[Code]),
+      sandbox:safe_goal(Code),
+      debug(r_plot,"Goal is safe.",[])
+   ),
+   insist(with_temp_dir(Dir, (
+      render(F,Code,Dir,File, [size(W,H), ppi(PPI), font_name(FN), font_size(FS) ]),
+      debug(r_plot,'Replying with file ~s',[File]),
+      reply_file(File,F)
+   ))).
+
+
+render(png,Code,D,PNGPath,Opts) :- !,
+   file_name_extension(tmp,png,PNGFile),
+   directory_file_path(D,PNGFile,PNGPath),
+   render(pdf,Code,D,EPSFile,Opts),
+   option(ppi(PPI),Opts,300),
+   run(sh(0>>0, "gs -dBATCH -dNumRenderingThreads=2 -dEPSCrop -dNOPAUSE -sDEVICE=pngalpha -sOutputFile=~s -r~d -q ~s",
+                     [PNGPath+write,\PPI,EPSFile+read])).
+
+% render(png,Code,D,Opts) :- !, option(ppi(PPI),Opts,300), render(png(PPI),Code,D,Opts).
+render(Fmt,Code,Dir,Path,Opts) :- 
+   file_name_extension(tmp,Fmt,File),
+   directory_file_path(Dir,File,Path),
+   debug(r_plot,'Running ~q',[print_fig(Fmt,Code,Path,Opts)]),
+   with_mutex(r_plot,api_r_plot:print_fig(Fmt,Code,Path,Opts)).
+
+print_fig(Fmt,Code,Path,Opts) :-
+   debug(r_plot,'In print_fig...',[]),
+   option(size(Width,Height),Opts),
+   maplist(cm_inch,[Width,Height],[WidthInches,HeightInches]),
+   debug(r_plot,'Getting device ~w: ~s',[Fmt,Path]),
+   dev(Fmt,Path,WidthInches,HeightInches,Dev),
+   debug(r_plot,'Got device ~q',[Dev]),
+   setup_call_cleanup( 
+      r(Dev), 
+      call_cleanup( 
+         with_output_to(string(_),Code), 
+        exception(Ex), 
+        debug(r_plot,'Exception running R code: ~q',[Ex])),
+      r('dev.off()')).
+
+dev(pdf,Name,W,H,pdf(+Name,width=W,height=H)).
+dev(eps,Name,W,H,cairo_ps(+Name,width=W,height=H)).
+dev(svg,Name,W,H,svg(+Name,width=W,height=H)).
+dev(png(PPI),Name,W,H,png(+Name,width=WP,height=HP)) :- WP is PPI*W, HP is PPI*H.
+
+cm_inch(CM,INCH) :- INCH is CM/2.54.
+