MaplePrimes - comments on Post, Trouble with arrows=line option in DEplot

MaplePrimes - comments on Post, Trouble with arrows=line option in DEplot http://www.mapleprimes.com/posts/136385-Trouble-With-Arrowsline-Option-In-DEplot en-us 2026 Maplesoft, A Division of Waterloo Maple Inc. Maplesoft Document System Tue, 09 Jun 2026 20:59:27 GMT Tue, 09 Jun 2026 20:59:27 GMT The latest comments added to the Post, Trouble with arrows=line option in DEplot http://www.mapleprimes.com/images/mapleprimeswhite.jpg MaplePrimes - comments on Post, Trouble with arrows=line option in DEplot http://www.mapleprimes.com/posts/136385-Trouble-With-Arrowsline-Option-In-DEplot You could use :-line http://www.mapleprimes.com/posts/136385-Trouble-With-Arrowsline-Option-In-DEplot?ref=Feed:MaplePrimes:Trouble with arrows=line option in DEplot:Comments#comment136388 You could use :-line. By the command with(plottools); the variable line has been defined to be plottools:-line. Thus you would write DEplot(deq1,x(t),t=-.5..4,x=-0.2..2,IC,linecolor=black,thickness=3,arrows=:-line); The latest comments added to the Post, Trouble with arrows=line option in DEplot 136388 Sat, 11 Aug 2012 11:46:39 Z Preben Alsholm Preben Alsholm global vs local clash http://www.mapleprimes.com/posts/136385-Trouble-With-Arrowsline-Option-In-DEplot?ref=Feed:MaplePrimes:Trouble with arrows=line option in DEplot:Comments#comment136397 This is an example of the well known issue of global vs local name clash: the procedure expects an unassigned global name as argument, but receives an exported local name instead which was bound to the same name by use of with, as Preben said. In this example plottools:-line, whose value is a procedure. Certainly, this issue and its "solution", globalizing the name by hand, using the collon dash prefix, is documented in <a href="http://www.maplesoft.com/support/help/search.aspx?term=with">?with</a>. In this example, :-line, as Preben also said. Yet, the status of this issue and its solution is disputed. For some people this is at most a weakness and the globalization trick is all that is needed. Or, in any case, a better, automatic solution is not a priority. For me, it is a design bug that should have been solved years ago. With tens of exports by a typical package, and tens of options in commands of another package, say, chances of name clash are, on the one hand significant, and on the other hand difficult to foresee. Thus, most likely, the user will realize that something is wrong only after receiving the error message. Then, an experienced user may remember to use this globalization trick, but most users will not realize what happens and will be left clueless as they are using the command as instructed in its help page. Moreover, as no warning is produced by name rebinding as it occured by executing with before of Maple 10. The interesting thing is that better solutions seem possible. On the one hand, some top level and package commands give context to the arguments being passed, which get "recycled" looking for a match to valid arguments. This example was provided by the developer some years ago: <pre>> M := module() export erf; option package; end module; > with(M); # here erf gets rebounded to M:-erf [erf] > FunctionAdvisor(syntax, erf); # even so, there is no problem here erf(z) </pre> Also, <a href="http://www.maplesoft.com/support/help/search.aspx?term=coercion">?coercion</a> , introduced in Maple 16, could provide another way. The latest comments added to the Post, Trouble with arrows=line option in DEplot 136397 Sat, 11 Aug 2012 15:15:28 Z Alejandro Jakubi Alejandro Jakubi DEtools[DEplot] http://www.mapleprimes.com/posts/136385-Trouble-With-Arrowsline-Option-In-DEplot?ref=Feed:MaplePrimes:Trouble with arrows=line option in DEplot:Comments#comment136402 I agree with Alejandro that the :- trick is way too advanced. A less advanced trick which I use all the time is that instead of loading package at the start, I call them when needed, e.g. DEtools[DEplot](deq1,x(t),t=-.5..4,x=-0.2..2,IC,linecolor=black,thickness=3,arrows=line); This approach avoids potential interferences. I do this mostly to remind myself about which package the command belongs to. It is occasionally awkward when the packages have long names and you are nesting several calls, but so far I've been able to live with it. The latest comments added to the Post, Trouble with arrows=line option in DEplot 136402 Sat, 11 Aug 2012 23:02:17 Z PatrickT PatrickT Use capitals http://www.mapleprimes.com/posts/136385-Trouble-With-Arrowsline-Option-In-DEplot?ref=Feed:MaplePrimes:Trouble with arrows=line option in DEplot:Comments#comment136462 Unfortunately not well documented in <a href="http://www.maplesoft.com/support/help/Maple/view.aspx?path=DEtools/DEplot">?DEplot</a>, but you can always(?) use capitals for the options to avoid this kind of confusion: <pre>DEplot(deq1,x(t),t=-.5..4,x=-0.2..2,IC,linecolor=BLACK,thickness=3,arrows=LINE);</pre> The latest comments added to the Post, Trouble with arrows=line option in DEplot 136462 Tue, 14 Aug 2012 13:26:41 Z Adri vanderMeer van der Meer Adri vanderMeer van der Meer @Adri vanderMeer van der Meer   http://www.mapleprimes.com/posts/136385-Trouble-With-Arrowsline-Option-In-DEplot?ref=Feed:MaplePrimes:Trouble with arrows=line option in DEplot:Comments#comment136477 <a href="http://www.mapleprimes.com/posts/136385-Trouble-With-Arrowsline-Option-In-DEplot#comment136462">@Adri vanderMeer van der Meer</a>   Excellent.  That will solve my problem. How did you find this work around? The latest comments added to the Post, Trouble with arrows=line option in DEplot 136477 Tue, 14 Aug 2012 21:16:14 Z jaytreiman jaytreiman list of alternative names http://www.mapleprimes.com/posts/136385-Trouble-With-Arrowsline-Option-In-DEplot?ref=Feed:MaplePrimes:Trouble with arrows=line option in DEplot:Comments#comment136490 The list of alternative names for the diverse arrow types is hardcoded in the line 116 of `DEtools/DEplot`: <pre>> showstat(`DEtools/DEplot`,116); `DEtools/DEplot` := proc(inDES, invars, trange) local DES, nDES, vars, dvar, ivar, highorder, totalorder, dvrange, linepts, initial, ninits, iter, lims, toplot, f, IC, w, eivar, fldcolor, arrowpts, test1, test2, stopp, dirfld, label_ftr, line_color, arrlen, userarrs, hasindep, lv, color_l, multi, t_s, data, alldata, maxv, arrs, defnpoints, npoints, nsteps, h, arrw, grid, m, n, o, numarrow, nullcl, nullclcolor, nullclgrid, nullclfill, nullclthick, anicurve, anifield, aniboth, nframes, allarrs, plot3dftr, plot2dftr, numftr, plot_ftr, dsol_ftr, meth_ftr, thick, plot3, bd, per, t1, t2, t3, t4, np, i, j, k, l, r, opt; global _plotDigits; ... 116 allarrs := [['curve', ['CURVE', 'tads', 'TADS'], 'CURVE'], ['comet', ['fish', 'Fish', 'FISH', 'Comet'], 'FISH'], ['line', ['LINE'], 'LINE'], ['small', ['SMALL', 'thin', 'THIN'], 'SMALL'], ['medium', ['MEDIUM', 'slim', 'SLIM'], 'MEDIUM'], ['large', ['LARGE', 'thick', 'THICK'], 'LARGE'], ['none', ['NONE'], 'NONE'], ['mediumfill', [], 'mediumfill'], ['smalltwo', [], 'smalltwo'], NULL] ... end proc </pre> As you see, this is a list of lists, one for each arrow type, whose first element is the "main" name (e.g. curve), and then alternative names including capitalization variations (CURVE, tads, TADS). The latest comments added to the Post, Trouble with arrows=line option in DEplot 136490 Wed, 15 Aug 2012 05:42:08 Z Alejandro Jakubi Alejandro Jakubi