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Re: can mathematica do this, please answer
Posted:
Jun 16, 1996 1:38 AM


In article <4p35oh$n9o@dragonfly.wolfram.com>, Gunnar Larsen <gunnarl@interlink.no> wrote: > >I want to read in an ascii file containing data >and plot each value in a sequence, generating an animated >graph. Each picture should be saved as a bitmap, (numbered >graf0000.bmp, graf0001.bmp.....) >This is going to be laid out on video. >The bitmap saving must be automatic because it is a huge amount >of data dispalyed.
"The following information is based on experience with the Beta version of Mathematica 3.0".
There is a way to do this using version 3.0 of Mathematica. Here is an example from my forthcoming book, "Power Programming with Mathematica: The Kernel", which is due out in about a month  about the same time that version 3.0 is estimated to be released. (What a coincidence :) )
 begin excerpt 
12.3.3 Display 
Display[s, g] writes the Mathematica graphics object g to the stream s in PostScript format. If s refers to a notebook window, the graphic is rendered in the notebook. In general, however, you can use Display to write the PostScript to any stream, such as a file or pipe.
...
When you create a Mathematica graphic using any of the plotting commands, the return value from the function is a graphics object. The picture that you see on your screen is actually a side effect that is caused by passing the graphics object to the function specified by the DisplayFunction option.
Options[Plot, DisplayFunction] {DisplayFunction :> $DisplayFunction}
$DisplayFunction Display[$Display, #1] &
The system variable $Display contains a channel (a stream or list of streams) to which the PostScript form of graphics objects should be written. The notebook front end initializes $Display to "stdout". Thus, in a roundabout way, the default value of the DisplayFunction option is Display["stdout", #]&.
...
In version 3.0, Display takes an optional third argument that specifies a format for the graphics output. "MPS" (Mathematica PostScript) is the default, but other possible values include "EPS" (encapsulated PostScript), "GIF", "TIFF", "XBitmap" (XWindows), "MetaFile" (Microsoft Windows), and "PICT" (MacOS). (See the entry for Display in [Wolfram 96] $A.10 for a complete list of supported formats.) So, for example, if you want to write a GIF version of every graphic in a Mathematica session to a separate file, as well as seeing each graphic on the screen, you could do something like the following:
n = 1; $DisplayFunction = Function[g, Display[$Display, g]; Display["GIFfile"<>ToString[n++], g, "GIF"]]
 end of excerpt  Power Programming with Mathematica: The Kernel Copyright 1996 McGrawHill For more information: http://www.princon.com/dbwagner/PPK/description.html
Dave Wagner Principia Consulting (303) 7868371 dbwagner@princon.com http://www.princon.com/princon



