[metapost] New numbersystems for the graph package?
Densing Martin (PSI)
martin.densing at psi.ch
Mon Feb 18 09:21:04 CET 2019
Dear Luigi,
Thanks for your answer!
This removes the error, but it destroys the y-axis (no negative labels anymore).
>From my limited perspective, the problem seems to be: The graph-macro depends in several places on the finite, original numbersystem because of the Mlog transformation (which would be not needed with higher precision arithmetic).
Until there is a fix, perhaps an innocent user should be made aware by a conditional errormessage based on the numbersystem at the beginning of the graph-macro, or a note in the documentation?
Best,
Martin
From: luigi scarso <luigi.scarso at gmail.com>
Sent: Samstag, 16. Februar 2019 19:49
Cc: metapost at tug.org
Subject: Re: [metapost] New numbersystems for the graph package?
On Sat, Feb 16, 2019 at 3:37 PM Densing Martin (PSI) <mailto:martin.densing at psi.ch> wrote:
Dear metapost experts,
Many thanks to the metapost-coders for the introduction of the new numbersystems!
How can we ensure that the new numbersystems work with the existing, very helpful macros that are available with the usual TeX-disitributions? Most relevant would be the graph macros of John Hobby. Hence: Would it be possible to make the graph macros (and all the auxiliary macros, e.g. format etc.) work with all numbersystems?
Example:
"mpost -numbersystem=decimal http://test.mp" gives an error on the following file "http://test.mp", whereas just "mpost http://test.mp" runs smoothly. Version: MetaPost 2.000 (TeX Live 2017/W32TeX) on MS Windows.
File: http://test.mp
% 0 1.4
% 1 3.2
% 2 -4.5
% 3 8.0
% 4 9.0
% 5 4.0
% Data-file for graph can be included at beginning of source-file,
% because %<space>0 1.4 etc. is read by gdata marco until empty line
input graph
prologues := 3;
outputtemplate := "%j-%c.mps";
beginfig(1)
draw begingraph(10cm,10cm);
path p;
gdata("http://test.mp", $, augment.p(i, scantokens $2););
gdraw p;
endgraph;
endfig;
end
-----------------end file
Metapost's log (if numbersystem=decimal):
-----------------------------------------------------------
! Logarithm of -7000.000523787821841175847573036896 has been replaced by 0.
Gipick_->...i=1upto.mlog(xpart.Gmhh_-xpart.Gmll_)/
....
This is just one of several issues, for example the auxiliary "format" macro has also problems with the new numbersystems.
Thank you very much for your help.
In
texmf-dist/metapost/base/http://marith.mp:
vardef Mabs primary x = x*.5*2 enddef;
Can you try with
vardef Mabs primary x = x*1 enddef;
--
luigi
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