Re: New book on Mathematica Graphics is needed
- To: mathgroup at smc.vnet.net
- Subject: [mg18903] Re: New book on Mathematica Graphics is needed
- From: "P.J. Hinton" <paulh at wolfram.com>
- Date: Mon, 26 Jul 1999 14:27:45 -0400
- Organization: "Wolfram Research, Inc."
- References: <email@example.com>
- Sender: owner-wri-mathgroup at wolfram.com
On 25 Jul 1999, Ersek, Ted R wrote: > When would one want to use > Hierarchical Data Format This would be used if you wanted to interchange arrays of numerical or character data that correspond to certain data types, like a character or a 32-bit real number. > MAT matrix format Hopefully when migrating from Matlab to Mathematica :-). The MAT format is the format that was used by Matlab up to version 4 for saving matrices to a file. Matlab 5 uses a proprietary format for which there is no published spec, only an API for I/O. > PNG format At one time this was thought to be a replacemnt for Compuser GIF format after Unisys started demanding royalties from developers of software that read or wrote GIFs. The point of contention was that they have a patent on the algorithm (Lempel-Ziv-Welch) that is used to compress the image data. > portable graymap format, portable pixmap format, portable anymap > format, The lowest common denominator formats -- portable bitmap (PBM), portable graymap (PGM), and portable pixmap (PPM) are referred to collectively as portable anymap (PNM). These are often used as interchange format when writing graphics converters. The most prevalent example is the netPBM toolkit, which is a collection of shell tools that can be used in tandem to translate between bitmap formats. This allows developers to write 2N instead of N^2 converter programs. > Mathematica system-independent raster graphics format This is the format in which the front end stores bitmap caches of PostScript graphics cells and any cell that has been converted to a bitmap. It is not really of interest to an end user unless one is trying to generate notebooks that store bitmaps in a programmatic manner from the kernel. > Look at al the flavors of PostScript available: > Encapsulated PostScript Intended to be embedded within part of a larger PostScript document. > Mathematica abbreviated PostScript This is the PostScript that is understood by the notebook front end and is generated by the Mathematica kernel when it is asked to display a graphic. It contains a lot of abbreivated PostScript operators to reduce the size of the PostScript string stored by the front end. In order for PostScript interpreters to understand Mathematica-generated PostScript, some translation must be done that adds all of the macro definitions. In the old days, this was done by the shell script psfix and the DOS program RASTERPS.EXE. Nowadays, both the front end and the kernel have ways of doing this directly. > Encapsulated PostScript with device independent preview > Encapsulated PostScript with TIFF preview If you've ever inserted a raw EPS file into a word processor like Microsoft Word, you might find that all you see in the document is a dummy box that marks off the space occupied by the graphic. This is because most document preparation systems do not have built-in PostScript interpretation programs. The Adobe specs allow for a bitmap preview to be added to the EPS file so that an application can show the preview on screen instead of the dummy box. These are just two examples of such preview formats. On the Macintosh, PICTs can be stored in the file's resource fork, and under Windows, a Metafile preview can be supplied. > When would I want to use the various sound formats ? > They include: > AIFF format This is understood by Macintosh systems, I believe. > nu law encoding (.au) I think it's mu-law. On Unix systems that support sound, you can play .au files by a simple shell command. cat mysoundfile.au > /dev/audio > sound file format This is understood by NeXT systems. Some sound players may understand it. > The Help Browser says "In some formats, lists of frames for > animated graphics can be given". It clearly says this can be > done for with GIF format. In what other formats can we export > animations ? The TIFF format allows for multiple images to be included in a single file, but I don't think there are any animation (timing, looping, etc.) parameters supported by the base spec. It would be up to the displaying application to handle the timing of the graphic switches. -- P.J. Hinton Mathematica Programming Group paulh at wolfram.com Wolfram Research, Inc. Disclaimer: Opinions expressed herein are those of the author alone.