Hello!

I would like to start with the following set of 9 elements,
A = { E11, E12, E21, E22, E11+E12, E11+E21, E12+E22, E21+E22, E11+E12+E21+E22 }.

I need a procedure that takes each of those elements and creates 3 new ones in the following way: Eij becomes Eij1, Eij2, Eij1+Eij2. So for example, E11 will become: E111, E112, and E111+E112. And for example the fifth element in A (i.e. E11+E12) will become the 3 new elements: E111+E121, E112+E122, and E111+E121 + E112+E122.

Since each of the 9 elements gets triplicated, there will be a new set, call it B, with 27 elements.

B = {E111, E112, E111+E112, E121, E122, E121+E122, ... }

Now I want to repeat this process of triplicating again so that, for example, E111 becomes: E1111, E1112, and E1111+E1112. And so on. This new set C will have 81 elements. Now I want to repeat this one last time. The final set, D, will have 243 (3^5) elements. 

Step 2: 

For every pair of elements x and y in D, I want to compute z:=(x+y)mod2. If z already belongs to D, discard it, otherwise, place z in the set D2. Do this until there are no more elements to add together (note that if x+y is computed then I don't want y+x to be computed also--that's inefficient). Maybe the most efficient way is to perform all possibly combinations of x+y mod 2 to create the set D2 and then just go: D2 setminus D.

Step 3: For x in D and y in D2 perform all possible combinations of z:=(x+y)mod2 and place these in D3 then perform set subtraction again: D3 minus D2 minus D.

Repeat this process again: x in D and y in D3 to create new elements in D4. Repeat again until Dm is empty (that is, D(m-1) will be the last set that contains new elements). I'm expecting around 12 sets... 

The issue with this whole algorithm is that I often run out of memory so I need a clever way to do this, since this algorithm is essentially classifying 2^32 elements into disjoint sets. Thank you! 

I figured how to insert row in middle of a matrix using <<>> notation. But I am trying to stick to one notation which is the Matrix() and Vector() for now. 

Here is what I am trying to do. Insert a row in the third row of  Matrix. This works:

A:=< <1|2|3>,<4|5|6>,<7|8|9>>;
A:=<<A[1..2,..],<90|91|92>,A[3,..]>>;

But when I try

A:=Matrix([ [1,2,3],[4,5,6],[7,8,9]]);
A:=Matrix([ A[1..2,..], [91,92,92], A[3,..] ]);

Error, (in Matrix) this entry is too tall or too short: [91, 92, 92]

I also tried:
A:=Matrix([ A[1..2,..], Vector[row](91,92,92), A[3,..] ]);
A:=Matrix([ A[1..2,..],Matrix([[91,92,92]]), A[3,..] ]);

I am starting to think I should go back to using <<|,|,|>> notation, even thought I do not like it, but at least it seems more logical. 
How would you insert row in middle of matrix, using Matrix() constructor from an existing Matrix?

I have a polynomial p in two variables x and y, and I want to extract all the coefficients of p. For example, let p:=x^3+2*x*y^2-2*y^2+x, and I want to obtain the coefficient vector [1,0,0,1,0,2,0,0,-2,0], where 1,0,0,1,0,2,0,0,-2,0 are respectively the coefficients of x^3, x^2, x^2*y,x,x*y,x*y^2,y^0,y,y^2,y^3. In general, let 

p(x,y)=sum(sum(c_*{i, j}*x^(n-i)*y^j, j = 0 .. i), i = 0 .. n)

=c_{0,0}x^n

+c_{1,0}x^{n-1}+c_{1,1}x^{n-1}y

+c_{2.0}x^{n-2}+c_{2,1}x^{n-2}y+c_{2,2}x^{n-2}y^2

+\dots

+c_{n,0}+c_{n,1}y+c_{n,2}y^2+\dots+c_{n,n}y^{n}.

It is possible that some coefficients c_{i,j} are equal to 0. How to obtain the coefficient vector [c_{i,j},i=0..n,j=0..i] of p(x,y)?

Thanks a lot.

When the loop variable can be written as a unit step sequence, I never really distinguish between using

seq( f(i), i=m..n ), and

f(i) $ i=m..n

However I recent came across a case where the 'seq' construct ran about 2.5x faster. Is using 'seq' always faster? Does it depend on the function being evaluated? Why is there such a large difference in execution time

The original example which exhibited the problem is shown below, although after some experimentation, I have found other cases where 'seq' is faster (and plenty where it doesn't seem to make any difference!)

Example code for implementation using '$' is

restart:
ulim:=1000000:
t1:=time():
ans:= max
          ( { iquo(3*d, 7)/d $ d = 1..ulim }
             minus
            {3/7}
         ):
t2:= time()-t1;

Example code for for implementation using 'seq' is

restart:
ulim:=1000000:
t1:= time():
ans:= max
        ( { seq
            ( iquo(3*d, 7)/d, d=1..ulim )
          }
          minus
          {3/7}
        ):
t2:= time()-t1;

On my machine, the version using the 'seq' construct runs 2.5x faster

The help page for ?error says the following:

• A numbered parameter of the form %n displays the nth msgParam in lprint notation.

However this is not literally true if %n happens to refer to a Maple object.  When a Maple object is lprint-ed, it looks for the object's ?ModuleDeconstruct method and uses that.  But in fact if M is an object, an error call like

error "invalid input: object %1 is wrong", M

displays M using its module shell

   Error, invalid input: object  module() export.... local... option object; end module  is wrong.

This is ugly and seems to contradict the ?error help page.  Why isn't the ModuleDeconstruct method of M invoked?  It is one of the few circumstances where an object is displayed "raw" without using either its ModulePrint or ModuleDeconstruct methods.  And can anyone suggest a workaround?

Sorry, don't have access to Maple 18, the above is for my M17.

Thanks,

Ian.

I am learning a bit of Maple. I noticed I can use map and seq to obtain the same result I want. So I was wondering when to use each, or if it just a style issue or if there is more to it.

I am sure there are cases when map can only be used, and cases when seq() only can be used. But are there general rules of thumb to look for when deciding which to use? Here is an example of what I mean

restart;
plot( map(i->i*sin(t),[seq(i,i=.1..1,.2)]),t=-2*Pi..2*Pi);   #1
plot( [seq(i*sin(t),i=.1..1,.2)],t=-2*Pi..2*Pi);  #2

Both give the same result

I kind'a like map more myself, but seq is a little shorter in this case. Just looking for thoughts and hints from the experts.

One would expect that hitting F3 will split from _end_ of the current line (where the cursor is at).

But what Maple does is actually split everything from the current cursor location. Which means if the cursor happened not to be exactly at the end of the line, the current line itself will also be split and broken.

It is much more logical to split starting from end of current _line_ (where the cursor is at), not current character, because that is what normally one would want to do. One will have large block of code, and want to split it from one line down to the end.  It is a simple usability issue, which Maple UI seems to suffer allot from.

Is there a way to modify this behavior? I keep hitting F3 and forget to move the cursor to the end of the line before, and end up wasting time having to fix things afterwords since the line itself is split.

This is a typical problem of what I find when learning DynamicSystems. Basically, I create number of systems by changing one paramter (the damping ratio in this case) and want to plot the unit step of all of them on the same plot to compare the effect of the damping ratio.

I setup the TransferFunction, used Simulate to obtain the response of each to the same input. The problem comes when I want to plot the respones.  I have to use plot[odeplot] it seems. But this only like to take one response at a time.

I can't use plot() since I do not have the actual function of the response in time. Unless I try to extract the differential equation from the sytem object, solve that and get a solution then use plot(). But if I do all of this, what do I need DynamicSystems in first place? 

I will show what I tried. I am sure there is some way to do this in Maple I just do not know yet the correct function or setup.

restart;
alias(DS=DynamicSystems);
H:=(w,zeta)->w^2/(s^2+2*zeta*w*s+w^2);
sys:= (w,zeta)->DS:-TransferFunction(H(w,zeta)):
sol:=seq(DS:-Simulate(sys(1,zeta),Heaviside(t)),zeta=0.1..1.2,.2):

Now I want to plot all the solutions in sol. I wanted to use plot(...) only to be able to obtain the automatic coloring of each solution.

If I try to use plots[odeplot], it works, but only on one at a time:

plots[odeplot](sol[1],t=0..10);

If I try this, it fails:

plots[odeplot]([sol],t=0..10);

I can get each plot separatly and then use display() but then lose the automatic coloring of the lines:

plots:-display(seq(plots[odeplot](sol[i],t=0..10),i=1..nops([sol])));

I am looking for the above plot, but have the lines each colors differently. I also need to figure how to add legend later. But one step at a time. I can't hard code the color in the plots[odeplot] call itself, since I do not know what color to give each line. plot([....],t=0..) allready does this automatically. But I can't use it!

Just to give an idea of the kind of plot I am trying to obtain, here it is in Mathematica:

sys = TransferFunctionModel[w^2/(s^2 + 2 z*w*s + w^2), s];
zValues = Range[.2, 1.2, .2];
fun = OutputResponse[sys /. {w -> 1, z -> #}, UnitStep[t], {t, 0, 12}] & /@ zValues;
Plot[Evaluate@Flatten@Table[fun[[i]], {i, 1, Length[fun]}], {t, 0, 12}, Frame -> True, PlotRange -> {{0, 12}, {-.1, 1.7}}]

How to calculate the integral of (z-z0)*z/sqrt((x-x0)^2+(y-y0)^2+(z-z0)^2)
over the unit sphere {(x,y,z):x^2+y^2+z^2<=1}
under the assumtion x0^2+y0^2+z0^2<=1 (x0^2+y0^2+z0^2>1)?
Its physical interpretation suggests the integral can be expressed through  elementary functions of the parameters.

My tries are
VectorCalculus:-int((z-z0)*z/sqrt((x-x0)^2+(y-y0)^2+(z-z0)^2),[x,y,z]=Sphere(<0,0,0>,1)) assuming x0^2+y0^2+z0^2<=1;

and

VectorCalculus:-int(eval((z-z0)*z/sqrt((x-x0)^2+(y-y0)^2+(z-z0)^2),
[x=r*sin(psi)*cos(theta),y=r*cos(psi)*sin(theta),z=r*cos(psi)])*r^2*sin(psi),
[r,psi,theta]=Parallelepiped(0..1,0..Pi,0..2*Pi)) assuming x0^2+y0^2+z0^2<=1;

The both are spinning on my comp. Also

VectorCalculus:-int((z-1/4)*z/sqrt((x-1/2)^2+(y-1/3)^2+(z-1/4)^2),[x,y,z]=Sphere(<0,0,0>,1),numeric);

is spinning.
Edt. The omitted part of the code assuming x0^2+y0^2+z0^2<=1 is added.

I have a great problem with this integral and Maple gives two answers completely different:

so I get two different results :

or this:

In the first integral A get Lommels2 and If I get the Integral by using Taylor of  and after that I resum I get Lommels1.

Thank you.

Hi All,

I have a problem with regard to partial differential equations. I am using Lagrangian dynamics for a problem. First i have a function First i defined a function with two speeds of angles (first derivatives):

ODE := 5*(diff(theta1(t), t))+diff(theta2(t), t). This gives:

Now this gives an output. Lagrange (just a simple example now) demands that i now derive the obtained function with regard to the first derivative of theta1. In this case, the answer i want is 5. Now, if i give the command: 

diff(ODE, diff(theta1(t),t)), maple says go home. Does anybody know how to solve this? I have been searching for a solution all afternoon.

Thnx in advance!

I'm trying to write an algorithm that arranges the columns of an arbitrary 2xn matrix counter-clockwise starting at the point closest to (1,0). For example, when I input the matrix 

Q := Matrix([

       [ -1 ,  0 ,   0 , -1 ]
     , [  0 ,  1 ,  -1 ,  0 ]

]);

into the algorithm, I would like the output to be

R := Matrix([

       [  0 , -1 , -1 ,   0 ]
     , [  1 ,  0 ,  0 ,  -1 ]

]);

Is there any package that could help me with this? 

three equations,

f1=(256*((256*(-24610976415716501050652227*x+256*(-10153609683556422184100+374519398571124540883*y-4145573659500944095488*z))*(29427736469514379027531261659072347+58899562724319710108573382000184640*y-1732944474195510410991057714955859184*z))/((5042560366642267*x-256*(2446745837411900+4901398098088043*y-144207654645973248*z))^3)-(256*(-308518681989548429992935348850261+41445095210006425938788783390458*y-1638970396838251453451269879637336*z)*(-801790542801929135637671-732048260009923946735424*x+56975701334774517040256*y-187552638032246240630656*z))/((-3075770275504817+198931044892562752*x+14199788245258112*y-1122852841901814912*z)^3)+(5*(-89303793175477833893354121208000+6533090911353242906294143748495*y-32276910383172707359896832089932*z)*(-61468981380127448102256-5328427636421850183140*x+4647710007810227520885*y-13344414478836548348450*z))/((-46366672189358032-18896234711237580*x+3927118781169095*y+14705346416259850*z)^3)-(3*(9101665097092871812176+3063507166600182944940*x+6945927557350563805665*y+1052001549322007294950*z)*(19493858980629008651267653094056+93282964805436900100617577630195*y+42271355681070699741325611572830*z))/((46366672189358032+18896234711237580*x-3927118781169095*y-14705346416259850*z)^3)-(4*(39553725461800043367392+17203831108841472538824*x+45483386678520344593037*y+2703260049547565568088*z)*(52830583937680669669892057655944+303023948138837354463602341532495*y+134962043561465977901954677856080*z))/((92856945980914656+51329763147513032*x-8586501277743859*y-56199770659759016*z)^3)-((22670037111266004087968+12461845278544574559640*x+39219302812923818032157*y-46563087562792926056*z)*(95973949246309465842551069546976+723429769797021053206211106031819*y+317530466286898645427564085427048*z))/((50159316775994592+36243094308305160*x-4827156544231217*y-52318895858217464*z)^3)-(80*(4157117722725769078952+4534359335248895646832*x+26193979470458655189977*y-2382852476120229696128*z)*(205429639975670471114284923188348+2095815907391732802212116237430935*y+883539023887333564964405237094400*z))/((45070329471431608+130124049256651728*x-5583613021604317*y-387630670566282112*z)^3)-(16*(9439334964924689507817+17499514376929345709248*x+187907876794815451253888*y-21704870055089718153088*z)*(943164674716649969807523653958385+18130967224506023673179633045358720*y+7486136216172114262568716503454336*z))/((-3075770275504817+198931044892562752*x+14199788245258112*y-1122852841901814912*z)^3)+(80*(2304705299858575630109*x-256*(204828849006588248100+19508530860149228990861*y-2445924471668591306496*z))*(-179928369646271075844345534739549+3401432279430696137250330740801392*y+12500875943051297916024009205116096*z))/((5042560366642267*x-256*(2446745837411900+4901398098088043*y-144207654645973248*z))^3)+(80*(-805507884940017483975376678503744+52529278437993151034132605337909*y-620040027953848498781390188900552*z)*(-716026618045942942760*x+243780804476456624597*y-8*(408351630952413337484+89777022692195474597*z)))/((-50159316775994592-36243094308305160*x+4827156544231217*y+52318895858217464*z)^3)+(768*(61889933231497708820968+30294916915069669525488*x-4484037822343607626207*y+13934625423713945278848*z)*(16858970779944867265671037333379*y-176*(1546216290476124632111328928258+3134171189636832381705249359145*z)))/((45070329471431608+130124049256651728*x-5583613021604317*y-387630670566282112*z)^3)-(40*(1717566388539311579248*x+7025931019459451548321*y+48*(46537098413809906919-8301700878138964680*z))*(3434616943638241443585000648954199*y+320*(1107265969195848092307625165761+4643932844541992753284837619195*z)))/((85141430232132048+97951351741329392*x-8855616621991191*y-199920422688690560*z)^3)+(12*(88457226224862447127008+13504083955712971035976*x-6622138801690554356387*y+19322683651036147287512*z)*(36451820000039413375829754767131*y-8*(66864837166560711793644210325852+35619205657210451197984743698883*z)))/((92856945980914656+51329763147513032*x-8586501277743859*y-56199770659759016*z)^3)+(512*(45619694076424722199344+14936846773318822792976*x-3365788117861218576473*y+10130491989577935272320*z)*(12048859085295019197936041733505*y-6*(32519187452933223586671104614156+40471151781636260063426632487709*z)))/((85141430232132048+97951351741329392*x-8855616621991191*y-199920422688690560*z)^3)))/125;
f2=(128*((32768*(24610976415716501050652227*x-256*(-10153609683556422184100+374519398571124540883*y-4145573659500944095488*z))*(98990697209366584150952278657452+920305667567495470446459093752885*x-65799721166407263195366683527104*z))/((5042560366642267*x-256*(2446745837411900+4901398098088043*y-144207654645973248*z))^3)+(1024*(-10864227594859409007678067839115+566592725765813239786863532667460*x-3214793226869529893757297514562848*z)*(9439334964924689507817+17499514376929345709248*x+187907876794815451253888*y-21704870055089718153088*z))/((-3075770275504817+198931044892562752*x+14199788245258112*y-1122852841901814912*z)^3)+(40*(2938923392457131154149055759247753+8383263629566931208848464949723740*x-24821520393182477390523323699174560*z)*(4157117722725769078952+4534359335248895646832*x+26193979470458655189977*y-2382852476120229696128*z))/((45070329471431608+130124049256651728*x-5583613021604317*y-387630670566282112*z)^3)+(80*(1717566388539311579248*x+7025931019459451548321*y+48*(46537098413809906919-8301700878138964680*z))*(3017477155357435955713408172820441+3434616943638241443585000648954199*x-6875761229715351344214913955270620*z))/((85141430232132048+97951351741329392*x-8855616621991191*y-199920422688690560*z)^3)+(2*(1013986939222028224203834326214704+723429769797021053206211106031819*x-1002019231842824621894736024449560*z)*(22670037111266004087968+12461845278544574559640*x+39219302812923818032157*y-46563087562792926056*z))/((50159316775994592+36243094308305160*x-4827156544231217*y-52318895858217464*z)^3)+(2*(698833722744934775627393528218146+279848894416310700301852732890585*x-191427609122898840477329914007915*z)*(9101665097092871812176+3063507166600182944940*x+6945927557350563805665*y+1052001549322007294950*z))/((46366672189358032+18896234711237580*x-3927118781169095*y-14705346416259850*z)^3)+(8*(557016173590538671691101855964863+303023948138837354463602341532495*x-309197308873592242001670976702725*z)*(39553725461800043367392+17203831108841472538824*x+45483386678520344593037*y+2703260049547565568088*z))/((92856945980914656+51329763147513032*x-8586501277743859*y-56199770659759016*z)^3)-(128*(-57335208466953058729715954197164+96390872682360153583488333868040*x-372364031472286149332017066304111*z)*(45619694076424722199344+14936846773318822792976*x-3365788117861218576473*y+10130491989577935272320*z))/((85141430232132048+97951351741329392*x-8855616621991191*y-199920422688690560*z)^3)-(5*(-5058036108182894712997605343704+13066181822706485812588287496990*x-23584235630998237996607750176151*z)*(61468981380127448102256+5328427636421850183140*x-4647710007810227520885*y+13344414478836548348450*z))/((46366672189358032+18896234711237580*x-3927118781169095*y-14705346416259850*z)^3)-(256*(-35027435322808897803896166913833+101153824679669203594026224000274*x-443348667941077090029000877418626*z)*(61889933231497708820968+30294916915069669525488*x-4484037822343607626207*y+13934625423713945278848*z))/((45070329471431608+130124049256651728*x-5583613021604317*y-387630670566282112*z)^3)-(24*(-23539469566855513950637813409344+36451820000039413375829754767131*x-87577625291530403453057402554096*z)*(88457226224862447127008+13504083955712971035976*x-6622138801690554356387*y+19322683651036147287512*z))/((92856945980914656+51329763147513032*x-8586501277743859*y-56199770659759016*z)^3)-(112*(97743545586690977941666831119873+189463292388600804291605866927808*x-534599264249120709692835475330432*z)*(801790542801929135637671+732048260009923946735424*x-56975701334774517040256*y+187552638032246240630656*z))/((-3075770275504817+198931044892562752*x+14199788245258112*y-1122852841901814912*z)^3)-(2560*(2304705299858575630109*x-256*(204828849006588248100+19508530860149228990861*y-2445924471668591306496*z))*(-29205293090710790323990469408790736+212589517464418508578145671300087*x+1750806894610755007047140949242022912*z))/((5042560366642267*x-256*(2446745837411900+4901398098088043*y-144207654645973248*z))^3)-(160*(3266813047619306699872+716026618045942942760*x-243780804476456624597*y+718216181537563796776*z)*(52529278437993151034132605337909*x-4*(8646336391489439377118003754263+39602745269819371968458588313429*z)))/((50159316775994592+36243094308305160*x-4827156544231217*y-52318895858217464*z)^3)))/125;
f3=(128*((-24576*(3839508863935892182987929073642496+36103009879073133562313702394913733*x-87732961555209684260488911369472*y)*(24610976415716501050652227*x-256*(-10153609683556422184100+374519398571124540883*y-4145573659500944095488*z)))/((5042560366642267*x-256*(2446745837411900+4901398098088043*y-144207654645973248*z))^3)-(30720*(65108728870058843312625047943313*x-256*(4791937744017588738333042319232+569924119339438478856491194414721*y))*(2304705299858575630109*x-256*(204828849006588248100+19508530860149228990861*y-2445924471668591306496*z)))/((5042560366642267*x-256*(2446745837411900+4901398098088043*y-144207654645973248*z))^3)+(256*(650985307933227267490679218098413+935767027021514282821089562931792*x+12859172907478119575029190058251392*y)*(9439334964924689507817+17499514376929345709248*x+187907876794815451253888*y-21704870055089718153088*z))/((-3075770275504817+198931044892562752*x+14199788245258112*y-1122852841901814912*z)^3)+(1280*(114748411888321695540849692963124+110442377985916695620550654636800*x+775672512286952418453853865599205*y)*(4157117722725769078952+4534359335248895646832*x+26193979470458655189977*y-2382852476120229696128*z))/((45070329471431608+130124049256651728*x-5583613021604317*y-387630670566282112*z)^3)+(1600*(100744894915663705876272277122960+74302925512671884052557401907120*x+343788061485767567210745697763531*y)*(1717566388539311579248*x+7025931019459451548321*y+48*(46537098413809906919-8301700878138964680*z)))/((85141430232132048+97951351741329392*x-8855616621991191*y-199920422688690560*z)^3)+(16*(72249495731635781189477972681776+39691308285862330678445510678381*x+125252403980353077736842003056195*y)*(22670037111266004087968+12461845278544574559640*x+39219302812923818032157*y-46563087562792926056*z))/((50159316775994592+36243094308305160*x-4827156544231217*y-52318895858217464*z)^3)+(640*(505227745581172894057712966825000+155010006988462124695347547225138*x-39602745269819371968458588313429*y)*(3266813047619306699872+716026618045942942760*x-243780804476456624597*y+718216181537563796776*z))/((50159316775994592+36243094308305160*x-4827156544231217*y-52318895858217464*z)^3)+(2*(356681541401645116923690413208956+126814067043212099223976834718490*x+191427609122898840477329914007915*y)*(9101665097092871812176+3063507166600182944940*x+6945927557350563805665*y+1052001549322007294950*z))/((46366672189358032+18896234711237580*x-3927118781169095*y-14705346416259850*z)^3)+(8*(301993014170585471859024964195112+134962043561465977901954677856080*x+309197308873592242001670976702725*y)*(39553725461800043367392+17203831108841472538824*x+45483386678520344593037*y+2703260049547565568088*z))/((92856945980914656+51329763147513032*x-8586501277743859*y-56199770659759016*z)^3)+(128*(4874430224431350455160317539284048+1942615285518540483044478359410032*x-372364031472286149332017066304111*y)*(45619694076424722199344+14936846773318822792976*x-3365788117861218576473*y+10130491989577935272320*z))/((85141430232132048+97951351741329392*x-8855616621991191*y-199920422688690560*z)^3)+((1486971442137244004077030949061728+322769103831727073598968320899320*x-117921178154991189983038750880755*y)*(61468981380127448102256+5328427636421850183140*x-4647710007810227520885*y+13344414478836548348450*z))/((46366672189358032+18896234711237580*x-3927118781169095*y-14705346416259850*z)^3)+(512*(3005184872892536482128059816733656+1654842388128247497540371661628560*x-221674333970538545014500438709313*y)*(61889933231497708820968+30294916915069669525488*x-4484037822343607626207*y+13934625423713945278848*z))/((45070329471431608+130124049256651728*x-5583613021604317*y-387630670566282112*z)^3)+(192*(137644881571986015841084811827840+35619205657210451197984743698883*x-10947203161441300431632175319262*y)*(88457226224862447127008+13504083955712971035976*x-6622138801690554356387*y+19322683651036147287512*z))/((92856945980914656+51329763147513032*x-8586501277743859*y-56199770659759016*z)^3)+(64*(13728575451141247570683309821008705+13111763174706011627610159037098688*x-935548712435961241962462081828256*y)*(801790542801929135637671+732048260009923946735424*x-56975701334774517040256*y+187552638032246240630656*z))/((-3075770275504817+198931044892562752*x+14199788245258112*y-1122852841901814912*z)^3)))/125;

thank you in advance.

RandomCompositions:= proc(n::posint, k::posint)
local
C,
Compositions:= [seq(C-~1, C= combinat:-composition(n+k, k))],
Rand:= rand(1..nops(Compositions))
;
()-> Compositions[Rand()]
end proc:

R:= RandomCompositions(9,6):
n:= 10:
S:= 'R()' $ n;

S := [4, 1, 1, 1, 2, 0], [3, 2, 1, 1, 0, 2], [0, 1, 1, 0, 0, 7], [0, 1, 1, 5, 0, 2], [1, 0, 3, 1, 3, 1],

        [1, 3, 1, 1, 0, 3], [1, 4, 2, 0, 2, 0], [5, 0, 0, 3, 1, 0], [1, 1, 1, 4, 0, 2], [0, 1, 2, 1, 0, 5]

[4, 1, 1, 1, 2, 0] , [1, 1, 1, 4, 0, 2]  and [0, 1, 1, 5, 0, 2] , [0, 1, 2, 1, 0, 5]  are same number 

  but different order.

There are two same sequence. I want to  count  as one, and compile statistics the summation, and 

divide by 8.

the result

0=14/8

1=17/8

2=6/8

...

4=2/8

5=2/8

...

according to

http://www.maplesoft.com/support/faqs/detail.aspx?sid=32658

But the above does not work in Maple 18, windows: (I use worksheet)

restart;
assume(z>0):
interface(showassumed=0):
z;

Only the other solution works, which is using options->display->turnoff assumed variables tilda.

Why does not the above command work?