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How to define an array of pens
by Otared Kavian 22 Jun '20

22 Jun '20

Hi Hans, After learning from you how to define an array of colors and paths, I would like to know how is it possible to define a variable pen size. In the following working example below, I would like to replace MyPens[j] := pencircle scaled 2pt ; by something like MyPens[j] := pencircle scaled (2+j) pt ; but this does not work (neither do (2+j)*pt). Is it possible to specify the pen size according to the value of j, without using a structure like if j == -1 : MyPens[j] := pencircle scaled 1pt ; elseif j == 0 : MyPens[j] := pencircle scaled 2pt ; else : MyPens[j] := pencircle scaled 3pt ; fi (In my real example I have more than three values for j). %% begin example-array.tex \startMPpage string MyColors[] ; path MyPaths [] ; pen MyPens[] ; for j = -1 step 1 until 1 : MyPens[j] := pencircle scaled 2pt ; % I would like to say here (2+j) pt endfor MyPaths[-1] := (-1.5cm,1.5cm) -- (1.5cm,1.5cm) ; MyColors[-1] := "magenta" ; MyPaths[0] := (-2cm,2cm) -- (2cm,-2cm) ; MyColors[0] := "darkyellow" ; MyPaths[1] := fullcircle scaled 3cm ; MyColors[1] := "darkred" ; for j = -1 step 1 until 1 : draw MyPaths[j] withpen MyPens[j] withcolor MyColors[j] ; endfor \stopMPpage %% end example-array.tex Best regards: Otared

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How to define an array of colors in Metafun
by Otared Kavian 20 Jun '20

20 Jun '20

Hi all, I have a family of graphs to draw in Metapost and I would like to attribute a different color to each of them according to the value of a certain variable. Assuming that the path mygraph(j) depends on the variable j, which is computed within a lua code and passed to Metapost, I wonder if it is possible to define an array of colors named mycolor, so that I could say draw mygraph(j) withcolor mycolor(j) ; Here the variable j takes integer values (say between 1 and 10), and one would have defined mycolor(1) through mycolor(10). Thanks in advance for any help: Otared K.

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Variables in \useURL
by Nigel King 19 Jun '20

19 Jun '20

Hi Group, I want to insert a variable hyper reference into a pdf document. The following method does not work for some reason. \def\hyperref{http://www.website <http://www.website/>.com/abc/def} show \hyperref Gives the correct answer but \useURL[this_doc][\hyperref][][displayed text] \from[this_doc] Gives hyperef%20 as the url What am I doing wrong? TIA — Nigel nigel(a)nigelking.me.uk m:07917 803879 h:01364 642265 Abbey Moor, Moreleigh, Totnes, TQ9 7JW.

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lmtx
by Hans Hagen 19 Jun '20

19 Jun '20

Hi, Here's an update about what Wolfgang and I are doing in the lmtx code base i.e. where it differs from the mkiv code. Much has to do with cleaner code, less memory usage and less tracing clutter. To some extend it might be more efficient in terms of runtime, but in practice there is not much (measurable) to gain at the macro level wrt speed. Most bottlenecks are at the Lua end anyway. (1) macro arguments: In tex a macro argument is defined with numbers, so \def\foo#1#2{... #2 ... #2 ...} in luametatex we can have some variants #0 : the argument is picked up but not stored #- : the argument is ignored and not even counted #+ : the argument is picked up but no outer braces are removed There is some explanation in the evenmore document, like: \def\foo [#1]{\detokenize{#1}} \def\ofo [#0]{\detokenize{#1}} \def\oof [#+]{\detokenize{#1}} \def\fof[#1#-#2]{\detokenize{#1#2}} \def\fff[#1#0#3]{\detokenize{#1#3}} \meaning\foo\ : <\foo[{123}]> \crlf \meaning\ofo\ : <\ofo[{123}]> \crlf \meaning\oof\ : <\oof[{123}]> \crlf \meaning\fof\ : <\fof[123]> \crlf \meaning\fff\ : <\fof[123]> \crlf I mention this because you may encounter something other than #1 .. #9 in error reports or tracing. (2) interception of unmatched delimiters If you define macros like \def\foo[#1=#2]{...} the brackets and equal had better be there. However there is some trickery in the macro parsing that can be used to intercept cases where they are missing: optional tokens as well as forcing end of scanning (so if you see \ignorearguments and \ifarguments in the code, that is what we're talking about: premature quitting and checking why that happened and acting upon it: less hackery is needed but then of course also less possibility to 'show off how clever one is wrt writing obscure macros' ... so be it. Both (1) and (2) are relatively lightweight extensions that are downward compatible as well as have no impact on performance. We don't expect them to be used at the user level (where one seldom defines macros anyway) but we apply them in some low level macros (and might apply them more). One can measure better performance but only when applied millions of times which is seldom the case in context (we're often more talking thousands there than millions of expansions). (3) There is some more 'matching token sequences' code that is being applied stepwise but again this is normally not seen at the user level. It sometimes permits cleaner fully expandable solutions. (4) There are some additional if tests but these are already around for quite a while and probably went unnoticed anyway. (5) Nested conditions can be flattened by using \orelse and that's what happens now in quite some places in the lmtx code (it's already there for a quite a while and kind of well tested). Again this leads to less tracing, can in priniciple be more efficient, but also demands less multiple expand after situations. It also just looks nicer. (6) Upcoming code can use some more (simplified) grouping magic but that is something we need to test more (which is what we are doing now). Just that you know when you get some error and see unfamiliar primitives, Hans ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl -----------------------------------------------------------------

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update
by Hans Hagen 19 Jun '20

19 Jun '20

Hi, I uploaded an update. I cleaned up (upgraded code-wise) some of the script related code. Most users won't notice but who knows if I introduced some issues with cjk ... just let me know if I overlooked something. Hans ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl -----------------------------------------------------------------

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Checking existence of a macro (control sequence) by Lua - problem after updating MkIV
by Lukas/ConTeXt 19 Jun '20

19 Jun '20

Hello, I'm using Hans' macro suggested some time before. I've just updated Ctx MkIV and my sample code: ---- \starttext \def\MyMacro{Ahoj} \def\MyMacWithPars#1#2{Something} \def\Undefined{} \let\Undefined\undefined \def\DoNothing{} \let\DoNothing\donothing \startluacode if CONTEXTLMTXMODE == 0 then local d = tokens.defined local c = tokens.create function tokens.defined(s,b) if b then return d(s) else return c(s).cmd_name == "undefined_cmd" end end end -- local defined = tokens.defined for _, v in ipairs{ "MyMacro", "MyMacWithPars", "Undefined", "DoNothing", "NonExisting" } do print(string.format("\letterpercent-12s", v), defined(v), defined(v, true), defined(v, false)) end \stopluacode Aaa \stoptext ---- gives: " MyMacro false false false MyMacWithPars false false false Undefined false false false DoNothing false false false NonExisting false false false " IOW, I'm not able to determine whether a control sequence has not been defined (or has \undefined value) or not. Am I doing a trivial mistake or has anything changed? Thank you for patience... Lukas

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margin comment above heading
by Pablo Rodriguez 18 Jun '20

18 Jun '20

Dear list, I have the following sample: \startsetups[tinytiny] \setupwhitespace[-2em] \setupbodyfont[0.01pt] \setupinterlinespace[1sp] \stopsetups \setupinteraction[state=start] \showframe\showgrid \starttext \blank[force, 10em] \section{Move comment above this heading} \startparagraph[setups=tinytiny] \dontleavehmode \comment[location={rightmargin}, color=orange] {comment} \stopparagraph \stoptext Is there a way to move the comment above the heading that goes before? Many thanks for your help, Pablo -- http://www.ousia.tk

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\blank space at the top of a page
by James Withers 18 Jun '20

18 Jun '20

Hello list I have been trying to find a solution to how to insert blank lines before a chapter heading at the start of a page. In the following example the \blank[4*big] is ignored. The solution I've found is to add an empty box using \mbox{} before the \blank command. Is this the right way to do it or is there a more elegant way that I am missing? Many thanks James \setuphead[chapter][before={\blank[4*big]}] \starttext \startchapter[title={No space above this chapter}] chapter text etc \stopchapter \setuphead[chapter][before={\mbox{}\blank[4*big]}] \startchapter[title={Chapter with the right spacing}] chapter text etc \stopchapter \stoptext

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How could I find the 'depth' of an element found with xml.first()?
by Gerben Wierda 18 Jun '20

18 Jun '20

Given the following XML snippet <opa id=“opa"> <Foo name="SubFoo Level One" id="Foo"> <Foo name="SubFoo Level Two" id="Foo_2"> <bar id="Bar" name="A Bar"> <bar name="Bar Level Three" id="Bar_2"> <Foo id="oma">OmaFoo</Foo> </bar> </bar> <Foo name="Fuzz Level Four" id="Fuzz"/> </Foo> <Foo name="SubFoo Level Two" id="Foo_3"> <fuzz name="Fuzz" id="Fuzz_2"/> </Foo> </Foo> </opa> How would I go about to find the depth of an item found with an LPATH? E.g. //[id="Foo_3"] would find a node at depth 2 (assuming <opa> is at level 0) while //[id=“Fuzz_2"] would find a node at depth 3 and in either cases I would like to get that number (2 or 3) as well as the actual node. I can assume the values for ‘id’ are unique. I was wondering how I could go about finding the ‘depth’ of an item in the XML when using the LMTX built-in functions to work with XML. I don’t think there is a default function for that, is there? G

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Re: [NTG-context] (no subject)
by Malte Frank Gerdes 18 Jun '20

18 Jun '20

I am rarely using mailing lists, so i hope that i do it right :). Thanks for the help, Taco. I added an entry to the Wiki, but i'm not sure if it is sufficient this way and if it needs approval/review or something. Malte

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