Re: Question about Display
- To: mathgroup at yoda.physics.unc.edu
- Subject: Re: Question about Display
- From: twj
- Date: Wed, 21 Apr 93 08:22:58 CDT
David Deutsch writes:
> If you save a graphic using the function
>
>Display["filename",graphics]
>
>can you read this graphic back into your Mathematica session?
>
>In[6]:= p1 = Plot[Sin[x],{x,0,2Pi}]
>
>Out[6]= -Graphics-
>
>In[7]:= Display["plot1", p1]
>
>Out[7]= -Graphics-
>
>In[8]:= Clear[p1]
>
>In[9]:= p1 = <<plot1
>
>Syntax::sntx: Syntax error in or before
> "/Courier findfont 10 scalefont setfont". (line 5 of "plot1")
> ^
In this example Mathematica is attempting to parse the contents
of the PostScript file as input. The PostScript will not parse
as valid input. It is possible to read it in as a string.
This can be done with ReadList:
ReadList[ "plot1", Record,RecordSeparators->{}]
in the example above will read the entire file into a string.
This may not be what is intended. What may be desired is
to turn the PostScript back into a Mathematica graphics
object. This is not intrinsically impossible for a limited
set of PostScript operators but is it necessary? It is quite
straightforward to keep the original Mathematica graphics
object.
In[46]:= p1 >> plotobject
In[47]:= p2 = << plotobject
Out[47]= -Graphics-
will save it in the file plotobject and then read it back in again.
Tom Wickham-Jones
WRI