Hi
I am trying to define commutation rules between operators a1, a2, b1, b2.

restart; 
with(Physics); 
with(Library); 
Setup(mathematicalnotation = true); 

Setup(op = {a1, a2, b1, b2}); 
alias(A = %AntiCommutator); 
algebra := [A(a1, a1) = 0, A(a2, a2) = 0, A(a1, a2) = 0, A(b2, a1) = 0, A(a1, b1) = 1, A(a2, b2) = 1];
Setup(algebrarules = algebra); 

However, the command Setup(algebrarules = algebra); causes an error. What is wrong? Noteworthy that if commutator is considered instead of anticommutator alias(A = %Commutator); then correct result follows.
Thank you.

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! 

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

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!

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.

Here is my code & the error mesage.  What's wrong?

with(Statistics);
X := Vector*([0, 5, 10, 15, 20, 25, 30], datatype = float);
Y := Vector*([38.8, 53.8, 82.4, 107.6, 130.7, 152.4, 173.2], datatype = float);
NonlinearFit(av^2+bv+c, X, Y, v);
Error, (in Statistics:-NonlinearFit) invalid input: PostProcessData expects its 1st argument, x, to be of type {array, list, rtable}, but received w

let A be a matrix=

[  7        7      9    -17

   6        6      1    -2

 -12    -12    -27    1

   7       7      17   -15 ]

What is the reduced row echelon form of A?

What is the rank of A?

cilrcle.mw

i want to plot a circle with that centered at (0,0),and the radius is the length of Point2 and orgin

but it shows the error

how could i do to solve this

How to make Decimal number in maple by default? 

How to make radian to degrees? Think It is like this "degcos" but I cant see the correct result, because it is not showed in decimals

Why do I have to active all my varibles when I open the document after I have saved it?

Regards

Østerbro

Dear.All

I'm a beginner of Maple 13. 

In MATLAB, there is a command 'sigmaplot' which draw the 'SINGULAR VALUE OF SYSTEM H(jw)' over all frequency range. 

I want to obtain the function of the 'sigmaplot' graph about frequency variable 'w'.

so I defined matrix A,B,C,D in Maple13. 

and specify H like following

H:= Multiply(C,Multiply(Inversematrix(s*IdentityMatrix(8)-A),B))+D              

          --> It is to express H=C*((sI-A)^-1)*B+D that is the state-space matrix of frequency domain form.

and Maple 13 gave me a very long formular expressed by 's'.

Then I try to 'SingularValues' command 

but there came up 'Error Message : Error. (in content/polynom) general case of floats not handled'

I couldn't resolve this problem.... 

So I'm requesting your advice like this.

Could you give some advice ? 

I wnat to print the polar that contain a part of loops,but it always contains all loops.

how do I solve this preblem?

Any one can help me,please?

Hi all,

I try  to plot phase portrait the below DAEs, 

diff(S(t), t)=-β*(1+δ*sin2Πt)*S(t)*I(t)-μ*S(t)+μ,

diff(I(t), t)=β*(1+δ*sin2Πt)*S(t)*I(t)-γ*I(t)-μ*I(t),

0=S(t)+I(t)+R(t)-1.

where

μ=0.01,

β=1510,

δ=0.02,

γ=50,

I really appreciate your help.

Hi,

  I have a loop code, such as

****

i_max:=10;

for i from 1 to i_max do
  blah blah blah

end do;

****

  I would like to clean memory, something like restart suppose to do, after each cycle. Restart could only work at top level. How should I do to clean memory after each cycle?