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author | asami <asami@FreeBSD.org> | 1996-12-24 07:42:52 +0000 |
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committer | asami <asami@FreeBSD.org> | 1996-12-24 07:42:52 +0000 |
commit | 0bb7d130c87e2474953a840d89d1524b17d77b3f (patch) | |
tree | e3b97ed2b45a9410442a0435b705aeac93a3062a /graphics/pgperl | |
parent | 05900502fbdd7702a4d50596001fd9c33b1a3bea (diff) | |
download | FreeBSD-ports-0bb7d130c87e2474953a840d89d1524b17d77b3f.zip FreeBSD-ports-0bb7d130c87e2474953a840d89d1524b17d77b3f.tar.gz |
Shorten this file. Please, don't put the entire 218-line README here! :(
Diffstat (limited to 'graphics/pgperl')
-rw-r--r-- | graphics/pgperl/pkg-descr | 205 |
1 files changed, 1 insertions, 204 deletions
diff --git a/graphics/pgperl/pkg-descr b/graphics/pgperl/pkg-descr index 6ee3207..8b43a1e 100644 --- a/graphics/pgperl/pkg-descr +++ b/graphics/pgperl/pkg-descr @@ -1,218 +1,15 @@ -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - PGPERL - A GRAPHICS EXTENSION FOR PERL. - ------ - A MACRO LANGUAGE FOR PGPLOT. - -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -INTRODUCTION ------------- - 'pgperl' is a version of the Perl language which has available the PGPLOT FORTRAN library, a very popular package for plotting astronomical data. (As a glance through any issue of ApJ or MNRAS will confirm.) The details of this involve some complicated C glue routines but are transparent to the user. -The idea is to provide a command langage for PGPLOT and a more -beautiful alternative to the various (incompatible) flavours of MONGO. -Personally I have always thought that PGPLOT produced far nicer plots -but at greater pain owing to the long compile/link/run cycle of F77 or -C. Wouldn't it be nice if one could call PGPLOT subroutines directrly -from the elegant perl language? Five days after reading `Programming -Perl' I found myself at a telescope with little to do, so I hacked out -the basics of `pgperl'. The rest followed during the odd spare evening -in Cambridge. - -Unlike MONGO, perl is a real C-like language with full control -structures, and is very fast and efficient. All the power of perl (and -believe me that is a *lot*) is available to extract data to plot from -multitudes of files in complicated free formats. Using pgperl one has -all the extra functionality of SM (v.t. `SuperMongo') and IMHO the -language is far more robust and elegant. Unlike the MONGOs pgperl is -free and public domain - though I trust people will communicate -improvements back to me to avoid version explosions. - -pgperl is *complete* - all the PGPLOT routines can be used and I have -tested most of them. - -I have tried very hard to keep the pgperl calls "obvious" to anybody -who knows PGPLOT and perl. See the notes below for examples of PGPLOT -use from pgperl. I refer people to the excellent reference manuals -available for PGPLOT and perl for complete information. - -The current version is 1.0 and is built with PGPLOT v5.0 commands. -There are versions availalable for perl4 (which requires making a new -perl executable linked with pgplot) and perl5 (as a dynamically loadble -perl5 module). If you use pgperl please drop me an email and I can put -you on my mailing list for updates. - -See the file LICENSE in the pgperl distribution for copyright/licensing +See the file LICENSE in /usr/local/share/doc/pgperl for copyright/licensing information and the file pgperl.doc on how to use pgplot from perl. This is also similar documentation on the pgperl WWW Home Page at: http://www.ast.cam.ac.uk/~kgb/pgperl.html -Many thanks to Frossie for the original inspiration, and to Larry Wall -and Tim Pearson for providing the excellent ingredients I stuck -together. - -enjoy (I hope), - -Karl Glazebrook, ---- -kgb@mail.ast.cam.ac.uk -Institute of Astronomy, Cambridge - -THE PERL5 VERSION OF PGPERL - CHANGES FROM PERL4 ------------------------------------------------- - -This file describes the use and enhancements of the pgperl package (PGPLOT -graphics for perl) with perl5. For installation instructions see the file -BUILDING. - - -LOADING PGPERL --------------- - -Since perl5 supports dynamic loading it is no longer necessary to make -a special version of the perl binary which has been linked with PGPLOT. -One just uses the normal perl5 binary and the statement: - -use PGPLOT; # Load PGPLOT module (perl5) - -will load in the PGPLOT module which contains all the C/perl necessary for -pgperl (assuming pgperl has been installed in the correct place). - -This replaces the older perl4 statement: - -require 'pgplot.pl'; # Obsolete - perl4 only - -This will still work though - it aliases to the new command - so all old -pgperl scripts should work unchanged with perl5, subject to the areas where -perl5 itself has a behaviour slightly different from perl4. These are rare -though and are changes for the better. - - -IMPROVEMENTS IN CALLING SYNTAX ------------------------------- - -In the old pgperl pgplot routines were called thus: - -&pgdraw($x, $y); - -In the new perl5 version the "&" is no longer necessary and one -can say: - -pgdraw($x, $y); - -Moreover all functions can now be used as list operators and so one -can even say: - -pgdraw $x, $y ; - -(Beware operator precedence though! - see perlop(1)) - - -IMPROVEMENTS IN ARRAY PASSING ------------------------------ - -In the old pgperl the only way to pass an array was to use the "*" -notation ("*x" passes a "glob reference" to all variables named "x"), -e.g.: - -&pgpoint($n, *x, *y, $symbol); # Still works - -This continues to work. However one can also pass new-style references -to individual arrays, e.g.: - -pgpoint($n, \@x, \@y, 17); # Direct reference - -or using variables to hold references: - -$xref = \@x; $yref = \@y; -pgpoint($n, $xref, $yref, 17); - -or even: - -pgpoint 3, [1,2,3], [4,5,6], 17; # Anonymous references - -See perlref(1) for all the grubby details on references in perl5. - - -SCALARS INSTEAD OF ARRAYS -------------------------- - -Because of the extra magic now built into pgperl it is possible to -use scalar variables with array routines, e.g.: - -$x=2; $y=4; -pgpoint(1, $x, $y, 17); # Plot a single point - - -This was not possible in perl4 which resulted in the creation of special -routines to deal with scalars, e.g. pgpoint1($x,$y,$sym). These old names -will still work, for easy backwards compatability, but they are no longer -necessary. - - -TWO-DIMENSIONAL ARRAYS ----------------------- - -perl5 now supports multi-dimensional arrays by means of the reference -syntax. (In fact it supports N-dimensional mixtures of normal arrays -and associative arrays but let's not go into that - see perlref(1)). - -In the old pgperl 2D arrays had to be passed to pgplot as one-D arrays, -e.g.: - -pggray(*img, $nx, $ny, 1, $nx, 1,$ny, $max, $min ,*tr); # @img is 1D - -This still works but is also now possible to pass a reference to a -2D array, e.g.: - -for($i=0; $i<128; $i++) { for($j=0; $j<128; $j++) { # Set up 128x128 image - $$img[$i][$j] = sqrt($i*$j) / 128; -}} -pggray($img,128,128,1,128,1,128,1,0,*tr); # Plot image - -The type of the array is automatically sensed - but make sure the array -is square and all the elements are defined! - - -Finally there exists a mechanism for efficient memory handling of large -images. They can be stored as byte-arrays in scalar variables and are -automgically sensed and passed onwards to the PGPLOT routines with no -conversion, e.g.: - -open(IMG,"test.img"); # Read in 128x128 image stored in file as binary -read(IMG, $img, 4*128*128); # data, i.e. list of 4 byte float [C type] /REAL*4 -close(IMG); # [f77 type] values, and store as perl string. -pggray($img,128,128,1,128,1,128,1,0,*tr); # Plot - -Obviously it is not possible to do any operations on such objects with perl -functions unless they are first converted to normal perl arrays (e.g. with -@image = unpack("f*",$img);) but this is useful for efficient passing around -of large images and one might imagine using library routines to read data -from files and return these structures. (Note: by "large" I mean >=1024x1024 -- for the 128x128 example it makes negligible difference.) - - -EXAMPLES --------- - -All these features are demonstrated in the new test script called -testpgperl10.pg (which only works with perl5). - -perl5 also has trendy object-oriented features - an example of -using this with PGPLOT is shown in testpgperl11.pg for the sake of -amusement. - - Karl Glazebrook, --- kgb@ast.cam.ac.uk Institute of Astronomy, Cambridge, U.K. -pgperl software: http://www.ast.cam.ac.uk/~kgb/pgperl.html - ------------------------------------------------------------------------------ - Last Modified. 18/May/1995. |