Mac Dude

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MaplePrimes Activity


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A bit hard to tell what you need since you did not upload the actual sheet (hint: the green up-arrow lets you upload your worksheet), but the _Ci are the constants you will usually find from your initial conditions (assuming you are solving an initial-value problem). E.g. the general solution for phi=0 and its derivative (for a 2nd-order problem).

The term phi=phi in the solution indicates that the solution does not depend on phi. IOW, you can pick any value (angle).

But you really should upload your Maple worksheet.

M.D.

@HS Yes exactly.

It is actually a nice feature.

However, if you create a worksheet from scratch and then save it somewhere, currentdir is not set to the directory where you save it but remains at its default (Maple's framework directory on macOS). You need to close and reopen  the sheet to get currentdir to change automatically.

M.D.

 

@Carl Love Carl, thanks much for the details on why the uneval quotes work. I actually did not know that.

M.D.

Do note that, when opening an existing worksheet, Maple sets currentdir() to the home directory of the sheet.

M.D.

I get that dialog when Maple's kernel crashes, or when I kill it deliberately.

Try running a simple "1+1" type worksheet and see if the kernel actually starts up.

M.D.

@eithne For me the MaplePrimes complaints came too late: I already upgraded (to deal with another issue I found in Maple 2019.0).

The problem in 2019.2 of not running the .mapleinit file is fatal for me: I don't get libname updated (to get at my packages) and therefore I cannot load my packages.

So I have to revert to Maple2018, since 2019.0 of course is gone now for me.

I really hope this gets fixed asap. Otherwise I'd have to consider terminating my subscription.

SCR was filed.

Mac Dude.

Edit: Ok, so now I realize that I had already forgotten what Rouben said 4 days ago... and I even answered to it. This is not good!

Oh well...

@Rouben Rostamian  Rouben, thanks for posting this; that bug is a bit of a killer for me.

Will hold off on upgrading.

M.D.

@acer Using labels fairly often i can confirm that is exactly the behaviour of Maple.

Using equation labels has a significant advantage over using %, %% etc: You always get the same result. % only works well if it refers to the previous result within the same execution group. If it refers to the previous execution group then % is something different if you evaluate it again; you pretty much have to run the whole notebook every time. Equation labels always refer to the labeled result. Moreover, equation label references get recalculated if you insert expressions, IOW if the label of the result you are referencing changed, all your references also change.

I find equation labels very well implemented and use them regularly. I only use % very rarely and always within an execution group. %, however, can refer to suppressed results; whereas labels cannot.

M.D.

@dingtianlidi Actually, if the problem can be transformed, it is much more efficient to use the product of Laplace transforms.

M.D.

@Carl Love Carl, while I agree with your notation being the correct one, my (sloppy) notation is in good company: Maple's own Help facility lists constructs like sin@@0, sin@@1 without the argument (see Help on @).  Needless to say, the argument is needed when you actually want to do something with the function.

M.D.

Not so clear about the f^4 part; but if f(x,y)=(x,y) then f(x,y) applied 4 times (which is how you define f^4 in your question) will also be (x,y). Then Maple can find a solution rather easily:

solve([x=f(x,y)[1],y=f(x,y)[2]],[x,y]);

Needless to say; f^4(x,y) might have other fixed points that are overlooked by this approach.

Mac Dude

fixed_point.mw

Edit: It turns out that another pair of fixed points exists for f(f(x,y)) that the above overlooked. These will be fixed points for f@@4 as well. But f@@4 is a polynomial of 15th order in x & y, and no general solution exists.

fixed_point_2.mw

@Thomas Richard I finally got around to downloading this to an old-ish iPad running iOS 9.3.5 or so (last one it can run). App downloads and starts up, but then dies without ever showing more than the splash screen. Repeatedly.

So, iOS 9 does not seem to be supported. Excuse the question, but did this app get tested on the different iOS versions?

Mac Dude.

 

In my experience getting this error almost always indicates a programming error (on my side).

Upload file! Big Green Up-Arrow!

Mac Dude

@acer I think you are right, except I would then have looked for a convert(xpr,string) construct, which as a matter of fact does exist. And convert can also do hex (as can sprintf).

The key take-away for me is the custom tickmarks definition. I knew I could use it to make tics in units of Pi, e.g., but using it with a list is new to me.

So, thanks both again,

M.D.

@acer , @Christian Wolinski  Thanks both very much. I think both your methods will work, but acer's wins on simplicity.

Mac Dude

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