tomleslie

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15 years, 163 days

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These are replies submitted by tomleslie

@Carl Love 

You mean although

assume(n,posint);

was given,

Maple cannot use it because "you need to use the positive integer property to do some sort of simplification."

Errr why do I need to do it? -  because Maple can't?

Like I said - "Hardly satsfactory"

Consider the following

restart;
assume(n,posint);
arg:=sin((n^2+1)/n*Pi);
exarg:=expand(arg, trig);
limit(arg, n=infinity);
limit(exarg, n=infinity);

Using the "expansion" of the triginometric function, the correct answer is obtained - otherwise not.

Hardly satsfactory!

@Preben Alsholm 

Having re-read the original question, and my response, I see no reason to revise the latter.

Maple  (unfortunately in my eyes) suffers from two different  "modes", two different "input formats", and three "interfaces".And most of the 12 theoretical combinations don't exist

The fact that i (like you) find it a right royal pain in the a** to occasionally convert between valid combinations did not seem appropriate for the OP's question

You appear to be uncertain about what an algebraic curve actually is - the wikipedia article is quite a useful introduction.

For the specific curve which you give, consider the output of

f := simplify(x^2*(y/x+sqrt(-7*y^2/x^2))/(y^2*(x/y+sqrt(-7*x^2/y^2))), symbolic);

 

@Carl Love 

Actually when I ran this worksheet in Maple 2015.1, the error message I got was

Error, `)` unexpected

I assumed some problem with 2-D math and didn't have the desire/energy to look any further.

I did try it in Maple 18 and got too many error messages to list

Don't think I can be much more help on this :-(

Intechanging graphics data between two software packages is a nightmare because even when you pick a specific format (such as EPS),you will find that the software doing the export is running EPS XX.XX.XXX and the  software doing the import is running EPS YY.YYY.YYY - so some things are almost guaranteed not to work!

However using the same two software packages, you might find by some miracle that both are running identical versions of (say) gif, so exporting/importing in this format will give identical results in the two packages. However they might be runnning different versions of eps, so one format *works* and the other doesn'. It's a lottery, which is why I said in my previous mesages

Whatever method, I have used in the past to export individual plots, I regard it as a bit of an "experimental" science. The ideal format/device often seems to depend on the software I am exporting to - which it shouldn't

It is also why I said that

I usually start with jpeg

Why? well I really, *really* don't want to start an argument about this, but my experience is that interchange of raster graphics tends to be more problem-free than interchange of vector graphics. Raster graphics just *seems* to be more tolerant of version mismatches between exportig and importing software - no way I can prove this,just my experience

As it happens postscript (ie ps and eps) are hybrid formats so AFAIK contain elements of both raster and vector graphics: if both the import and export software are running identical versions, then you get the best of both worlds. If they are running different versions then you can have the worst of both worlds - it's a nightmare!

 

I produced the following pdf, by

  1. exporting three plots from Maple in jpeg format
  2. setting up a 2*2 table in MSWord, turning off the all the table borders
  3. importing plots individually into the appropriate MS table cell
  4. saving the result as pdf

Visually, I don't see much quality difference between the arrayplot I started with in Maple and the final pdf

pltTest.pdf

@lt 

The plotsetup() approach to exporting plots was largely superseded in Maple 18 by plottools[exportplot]. Probably because plotsetup() was a pain to use!!!

Even in Maple 2015 plottools[exportplot]() does not handle the ARRAYPLOT structure: it probably *should*, but it doesn't, so I'd make an educated guess that there is no way to get the earlier plotsetup() export to handle an ARRAYPLOT structure :-(

Whatever method, I have used in the past to export individual plots, I regard it as a bit of an "experimental" science. The ideal format/device often seems to depend on the software I am exporting to - which it shouldn't

If it helps, I usually start with jpeg, [which seems to be an option for plotsetup(plotdevice)]: lots of colours, the ability to manually set the "canvas" size, and pretty much everything else will read it.

@lt 

The fact that blot.mw works is not "unexpected" - it follows required Maple syntax

The counterexample which you give is invalid because you do not supply rotate() with a single plot structure. You provide two plot structures, which so far as I know, rotate() will not handle.

so

A[2,2]:= rotate(plotStruct1, plotStruct2, Pi/2)

will not work, but I am prepared to bet that

A{2,2]:= rotate( display(plotStruct1,plotStruct2),  Pi/2)

will work, because the display(..) command will create a single plot structure.

I am also prepared to bet that

p1:= rotate(plotStruct1, Pi/2)
p2:= rotate(plotStruct2, Pi/2)
A[2,2]:= display([p1,p2])

will also work

To illustrate this point, I have extended my toy example to have two functions , sin() and cos(), and show how to supply these correctly to the rotate/refect/array commands in order to produce the required plots. I do this in both of the above two ways, to show that either variant will work

As in my previous post I am uploading the executed worksheet with outputs so that you can see what should be produced. Follow the instructions in my previous post to determine whether or not Maple 13 produces exactly the same - and report back with any discrepancies

cplot.mw

 

 

@lt 

I think most of the difficulty has to be associated with our different Maple versions. The attached worksheet contains a toy example showning the basics of reflect(), rotate() etc together with the output as produced with Maple 2015. I suggest you make two copies, one for reference and one for playing with.

Open the reference sheet - do not execute! - so that you can see what should happen

Open the "playwith" sheet, do nothing other than execute it using !!! in the Maple toolbar, and compare the output. If it isn't exactly the same, then upload this executed sheet (with output) so that I can see what Maple 13 is doing: I might be able to figure out a workaround

bplot.mw

@lt 

Thank you so much for helping me with this one. For once, I can also give you some useful information in return: I found this one http://www.mapleprimes.com/questions/35926-Histogram-Plotting-In-Maple concerning plotting absolute bin height numbers. It's the option "frequencyscale=absolute" and just add it to the other histogram options.

Only you know precisely what options you wish to apply to a histogram: I do not, because I am not psychic. I suggest you apply whichever select whichever histoggram option you want (and not expect me to guess what they are)

My last problem now is, that when I rotate the histogram in A(2,2), then the histogram axis parallel to the scatter plot y-axis turns to negative.

This one is my fault: I shold have realised that a simple rotation of the plot through 3*Pi/2, (or -Pi/2) would result in an inversion of the y-axis. However this can be simply fixed by reflecting the plots in the y-axis before (or after) the rotation (suggest you read the plottools/help): I have addde this capaility to the previous worksheet - see belo

aplot3.mw

I try to make a histogram dualaxisplot now with the frequencyscale=absolute on the left and a relative axis on the right - or vice-versa. Any suggestion?

So you want to plot the same data with two different axes??? The obvious answer to this is to produce the same plot twice, once with the y-axis on the left and once with the y-axis on the right. Check the plot/axis/location help. Assuming that you get the scaling correct, then the data will overlap exactly (appearing as one dat set) and you will get two (differrent?) y-axes

Concerning the axes, I think I still need all the axes displayed, because I can't find a way how to individually move and stretch/squeeze the histogramplots; so if I just switch of an axis, then it is not comparable anymore to the scatterplot axis. Suggestion for individually adjusting histogram positions?

Not really sure I understand this: the result appears as a table: if you grab the internal table boundaries (and drag) then you should be able to scale plots simulaneously. For example if you grabbthe internal vertical table boundary and pull it left or right, then both the scatterplot and the xvals histogram should "scale" together. Just grab the table borders, pull them around and see how things scale. If this doesn't work then I can only assume that it is a difference between Maple2015 and Maple13 which I won't be able to diagnose, becuase (as I said before) I have no access to Maple 13

 

@lt 

I can only operate with Maple 2015 and Maple18: I simply no longer have access to Maple13, so I cannot guarantee that anything I suggest will work for you.

You are now worrying a lot about aesthetics - what looks *right* to you may not look *right* to me, so I can only encourage you to experiment

The attached worksheet is a modification of my original for two distinct data sets

aplot2.mw

Answers to some of your questions:

  1. "Is it possible that the array grid is not displayed?" Yes: once the plot has been produced, right-click on the plot and you should get a menu from whch you can select Table->Properties and then switch off internal and external borders of the Table. Regrettably, I can find no way to do this programmatically. Not saying that it can't be done - I'm just not smart enough to do it :-(
  2. The attached worksheet does handle two data sets although you may want to play with transparency settings on the histograms.
  3. I was careful to set up these plots so that the "bins" on the histograms exactly aligned with the data on the scatterplot, so I don't really understand your comment in update2 above. In both the previous worksheet and the above, the histogram bins are rigged to align exactly with the scatterplot. If this isn't working for you then it is a Maple2015/Maple13 problem which I can't debug.
  4. I don't thnk that there is any way to turn on the "y"-axis on the histograms so showing the scale for the number of elements in each bin, without turning on the x-axis showing the bin widths., but I could be wrong. If I really had to do this I might try turning the axes on and setting the color of the x-axis to white (so it was there, but invisible) - or some such trick

 

@acer 

Thanks for the useful comment:

I no longer have access to Maple13.

When responding to questions involving versions prior to Maple 18, I'm always taking a bit of leap of faith. However I did hope by commenting that a "blank" plot was *needed*, this would be sufficient guidance. After all, how hard can it be to come up with a plot which has nothing in it!

SInce you do not provide the data it is difficult to give a definitive answer. However I woud be tempted to try either the DirectSeacrh[DataFit] command or Statistics[NonlinearFit]

The DirectSearch package is not technically a Maple product but an add-on package, so has to be downloaded and installed separately.

@brian bovril 

Oddly enough I did consider the possibility of placing the smallest cheese on top of the middling cheese, and cuttiing out the "overlapping" annulus of the middling cheese, and then cutting it in half. However I considered that this act constituted two cuts, which, added to the halving of the largest cheese, would result in three cuts

The issue of allowing right-angled direction changes in a "single" cut confuses mathematical accuracy with practicality. In a practical single cut of cheese you cannot execute a right-angle, so you end up with a "rounded" corner. As a result this approach seems clever in theory, but is guaranteed to fail in practice

Whilst the approach I suggested guarantees two cuts,and guarantees the equality of areas it does depend on the accuracy of measurement of an irrational number, so I admit that this too is probably also flawed :-(

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