Sorry Mike, I'm losing my marbles. This is what comes from replying on Chat (…why is this conversation being conducted on Chat?) without having a development machine handy to test conjectures.
…I was seeing "viewmat" and reading "plot". So… correction: jios doesn't use PDF for viewmat -- it generates a bitmap. This is the old way of doing it. I believe the latest JAL viewmat (I haven't looked) generates a PNG not a bitmap. This explains (for me) why jios is not showing arrows with a complex argument. Logged as a bug, to be fixed in next release of jios. On Mon, 6 Mar 2023 at 08:48, Ian Clark <[email protected]> wrote: > Mike -- I said earlier that jios generates a PDF and shows that. If plot's > PDF generation is omitting the arrows, then (a) it explains why jios is > getting it wrong, and (b) the same error should appear with JQt too. > > It'll be Friday before I can investigate this. I'm hoping someone else > will get there first. > > > On Mon, 6 Mar 2023 at 08:39, 'Michael Day' via Chat <[email protected]> > wrote: > >> No, not a pdf (as far as I know.) >> Just viewmat on a small complex matrix, and NO arrows were shown. >> You'll (Ian) know whether a pdf is used in the process! >> This was in Jios on my iPad. >> >> Mike >> >> On 06/03/2023 08:28, Ian Clark wrote: >> > Did I understand you right -- you tried outputting a PDF in JQt, and the >> > PDF contained arrows? >> > >> > On Sat, 4 Mar 2023 at 23:14, 'Mike Day' via Chat <[email protected]> >> wrote: >> > >> >> Yes, I tried in jios too, and was going to ask the forum how to get >> the >> >> arrows, but I then tried it in JQt under Windows on the laptop, where >> they >> >> did appear, pointing in what appeared to be the correct direction. >> >> >> >> Mike >> >> >> >> Sent from my iPad >> >> >> >>> On 4 Mar 2023, at 22:25, Ian Clark <[email protected]> wrote: >> >>> >> >>> Jan-Pieter wrote: >> >>>> Jios 903.1 gives the same result (i.e. colours, but not arrows). >> >>> When I get time I'll look into this. But for now I'll just say that >> jios >> >>> uses plot/pd to generate a *pdf* of the viewmat pic, which is what it >> >>> displays. Generation of the pdf might possibly be corrupt or >> incomplete. >> >>> >> >>> Might there be a font full of arrows missing? (Just a guess). >> >>> >> >>>> On Thu, 2 Mar 2023 at 14:33, Jan-Pieter Jacobs < >> >> [email protected]> >> >>>> wrote: >> >>>> >> >>>> I think Esa is right. >> >>>> It's explained with some examples in the viewmat lab, pages >> 8/20-12/20. >> >>>> >> >>>> It does not seem to work on Android though, just returning a blank >> >> window >> >>>> (while viewmat on real inputs works perfectly). >> >>>> >> >>>> On the J Playground, it ddes not work either: it just shows the >> >> magnitude, >> >>>> but not the arrows. Jios 903.1 gives the same result (i.e. colours, >> but >> >> not >> >>>> arrows). >> >>>> >> >>>> Jan-Pieter >> >>>> >> >>>>> On Thu, 2 Mar 2023, 14:02 esal, <[email protected]> wrote: >> >>>>> >> >>>>> I think it represents the angle (phase, argument) of the complex >> number >> >>>>> while the color is mapped to the magnitude (absolute value, length). >> >>>>> >> >>>>> Esa >> >>>>> >> >>>>> On Wed, Mar 1, 2023 at 7:21 PM Michal Wallace < >> >> [email protected]> >> >>>>> wrote: >> >>>>> >> >>>>>> What is the word for what the arrows mean in viewmat when you are >> >>>> looking >> >>>>>> at complex numbers? >> >>>>>> >> >>>>>> I think that multiplying a number by the arrow's corresponding >> point >> >> is >> >>>>>> going to do some kind of shearing (?) in that direction, but can >> >>>> someone >> >>>>>> help me put this concept into words? >> >>>>>> >> >>>>>> Thanks! >> >>>>>> -Michal >> >>>>>> >> ---------------------------------------------------------------------- >> >>>>>> For information about J forums see >> >> http://www.jsoftware.com/forums.htm >> >>>>> >> ---------------------------------------------------------------------- >> >>>>> For information about J forums see >> http://www.jsoftware.com/forums.htm >> >>>>> >> >>>> >> ---------------------------------------------------------------------- >> >>>> For information about J forums see >> http://www.jsoftware.com/forums.htm >> >>>> >> >>> ---------------------------------------------------------------------- >> >>> For information about J forums see >> http://www.jsoftware.com/forums.htm >> >> ---------------------------------------------------------------------- >> >> For information about J forums see http://www.jsoftware.com/forums.htm >> >> >> > ---------------------------------------------------------------------- >> > For information about J forums see http://www.jsoftware.com/forums.htm >> >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm >> > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
