MaplePrimes Posts

MaplePrimes Posts are for sharing your experiences, techniques and opinions about Maple, MapleSim and related products, as well as general interests in math and computing.

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Announcements 186 January 04 2012 by eithne
Applications, Examples and Libraries 199 February 05 2012 by Markiyan Hirnyk
Product Tips & Techniques 499 January 27 2012 by k4walker
MaplePrimes Commons General Technical Discussions 960 February 01 2012 by icegood
Education 164 January 27 2012 by Valery Cyboulko
MapleSim in Engineering Education 3 May 05 2011 by aninroy
Product Suggestions 212 February 01 2012 by icegood
MaplePrimes Suggestions 331 December 11 2011 by icegood
Personal Stories 143 January 31 2012 by pagan

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This is one of rank tests.
Non-parametric methods are widely used for studying populations that take on a ranked order (such as movie reviews receiving one to four stars).
The use of non-parametric methods may be necessary when data have a ranking but no clear numerical interpretation, such as when assessing preferences.
In terms of levels of measurement, non-parametric methods result in "ordinal" data.
After the introduction to the topic let's turn to an example.

One more argument for long double

February 01 2012 by icegood 190 Maple

If there are still doubts to support "long double" in evalhf then there is one more argument to implement them in at least those machines that support it:
CalcInEvalhfFast.mw

P.S. In that well-known holy war about long double supporting in compilers i'm rather on side of "to support them" than on side of (stupid) microsoft visual c++ compiler.

usenet quote

January 31 2012 by pagan 4255 Maple

A recent quote from a thread in sci.math.symbolic:

"FriCAS can produce various 3D plots.  Interface is not pretty, but the plots are." -- Waldek Hebisch

I don't even care if it's true (about FriCAS). I love the sense of priorities.

I created a procedure over a year ago to collect earthquake data from the usgs and save it into a file. The procedure pulls data off the internet and saves it in a text file with a date stamp (minus the year - because I haven't been bothered to change it ) in the folder location f:/7 day earthquakes.  Feel free to modify it as you wish.  Here it is, pretty much still in it's original format when I created it.

earthquakedatasave := proc ()
  local a, b, c, d, e, i:

The kick-off for this year's FIRST Robotics competition was held on January 7, 2012. The title for this year is Rebound Rumble. For those new to FIRST (For Inspiration and Recognition of Science and Technology), it is an annual event that lets high school student teams from around the world compete against each other in a game with robots that they build specifically to tackle the challenges posed to them by the organizer. This...

ZNO 2012

January 27 2012 by Valery Cyboulko 90 Maple

Ukaine-2012. External independent evaluation. A trial version in Maple, by Maple.
HTML, Java-Interactive:
http://webmath.exponenta.ru/zno_11/ranok/z.html
Maple:2012_ranok_ru_bez.mw

Maple Colors

January 27 2012 by k4walker 69 Maple

I was trying to put together a series of plots that each included multiple dataseries.  I wanted to color them to help distinguish the various curves.  When I went into Maple's help page for the "colornames" that Maple recognizes, I was surprised to find that there were no color swatches to help you pick what color you wanted to use.  So I copied the color names from the help into a worksheet and told it to plot some color swatches for me. Here is the result:

Check this:

111.mw

Don't forget set Plot0 component manipulator to "Click and Drag" to test "on click" event. Localizing of problem takes for me ~4 days. It's terrible!

 

---------for stupid tags

global

The directional derivative of a scalar function f(x), computed in the direction u in Cartesian coordinates, is defined by

Suppose that you wish to animate the whole view of a plot. By whole view, I mean that it includes the axes and is not just a rotation of a plotted object such as a surface.

One simple way to do this is to call plots:-animate (or plots:-display on a list of plots supplied in a list, with its `insequence=true` option). The option `orientation` would contain the parameter that governs the animation (or generates the sequence).

But that entails recreating the same plot each time. The plot data might not even change. The key thing that changes is the ORIENTATION() descriptor within each 3d plot object in the reulting data structure. So this is inefficient in two key ways, in the worst case scenario.

1) It may even compute the plot's numeric results, as many times as there are frames in the resulting animation.

2) It stores as many instances of the grid of computed numeric data as there are frames.

We'd like to do better, if possible, reducing down to a single computation of the data, and a single instance of storage of a grid of data.

To keep this understandable, I'll consider the simple case of plotting a single 3d surface. More complicated cases can be handled with revisions to the techniques.

Avoiding problem 1) can be done in more than one way. Instead of plotting an expression, a procedure could be plotted, where that procedure has `option remember` so that it automatically stores computed results an immediately returns precomputed stored result when the arguments (x and y values) have been used already.

Another way to avoid problem 1) is to generate the unrotated plot once, and then to use plottools:-rotate to generate the other grids without necessitating recomputation of the surface. But this rotates only objects in the plot, and does alter the view of the axes.

But both 1) and 2) can be solved together by simply re-using the grid of computed data from an initial plot3d call, and then constructing each frame's plot data structure component "manually". The only thing that has to change, in each, is the ORIENTATION(...) subobject.

At 300 frames, the difference in the following example (Intel i7, Windows 7 Pro 64bit, Maple 15.01) is a 10-fold speedup and a seven-fold reduction is memory allocation, for the creation of the animation structure. I'm not inlining all the plots into this post, as they all look the same.

restart:
P:=1+x+1*x^2-1*y+1*y^2+1*x*y:

st,ba:=time(),kernelopts(bytesalloc):

plots:-animate(plot3d,[P,x=-5..5,y=-5..5,orientation=[A,45,45],
                       axes=normal,labels=[x,y,z]],
               A=0..360,frames=300);

time()-st,kernelopts(bytesalloc)-ba;

                                1.217, 25685408
restart:
P:=1+x+1*x^2-1*y+1*y^2+1*x*y:

st,ba:=time(),kernelopts(bytesalloc):

g:=plot3d(P,x=-5..5,y=-5..5,orientation=[-47,666,-47],
          axes=normal,labels=[x,y,z]):

plots:-display([seq(PLOT3D(GRID(op([1,1..2],g),op([1,3],g)),
                           remove(type,[op(g)],
                                  specfunc(anything,{GRID,ORIENTATION}))[],
                           ORIENTATION(A,45,45)),
                    A=0..360,360.0/300)],
               insequence=true);

time()-st,kernelopts(bytesalloc)-ba;

                                0.125, 3538296

By creating the entire animation data structure manually, we can get a further factor of 3 improvement in speed and a further factor of 3 reduction in memory allocation.

restart:
P:=1+x+1*x^2-1*y+1*y^2+1*x*y:

st,ba:=time(),kernelopts(bytesalloc):

g:=plot3d(P,x=-5..5,y=-5..5,orientation=[-47,666,-47],
          axes=normal,labels=[x,y,z]):

PLOT3D(ANIMATE(seq([GRID(op([1,1..2],g),op([1,3],g)),
                           remove(type,[op(g)],
                                  specfunc(anything,{GRID,ORIENTATION}))[],
                           ORIENTATION(A,45,45)],
                    A=0..360,360.0/300)));

time()-st,kernelopts(bytesalloc)-ba;

                                0.046, 1179432                            

Unfortunately, control over the orientation is missing from Plot Components, otherwise such an "animation" could be programmed into a Button. That might be a nice functionality improvement, although it wouldn't be very nice unless accompanied by a way to export all a Plot Component's views to GIF (or mpeg!).

The above example produces animations each of 300 frames. Here's a 60-frame version:

The cost of some mathematical sites (estimated bizinformation.org):
 8.000.000 $ - wolfram.com
   372.456 $ - webmath.exponenta.ru (Russian Maple in education)
   292.301 $ - maplesoft.com

    82.342 $ - exponenta.ru
    61.278 $ - webmath.ru
    54.895 $ - math.ege
    43.302 $ - univ.kiev.ua (Kiev National University)

Integration anomaly

January 19 2012 by Stewart Herring 15 Maple

Problems concerning integration have been discussed on  maple primes  before with piecewise continuous antiderivatives explaining  difficulties. Here an example is given using Maple 15 where a continuous antiderivative is returned but definite integration fails to give the correct answer.

Integration_anomal.mw

MRB constant T

January 13 2012 by Marvin Ray Burns 465 Maple


Let c=MRB constant -1/2

In case if you like notepad++  under windows, and still didn't do smth like that then this is for you .userDefineLang.zip

Unpack to notepad++ folder. In case if you already had had other
own language then just copy "Maple language" section.

Poker Probabilities

January 11 2012 by alex_01 2963 Maple 13

I have below outlined the different probabilities for different poker hands given
5 cards from a 52 cards deck. The frequencies are from wikipedia
http://en.wikipedia.org/wiki/Poker_probability




These frequencies are quite interesting....I wonder if they found them by "brute fource"

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