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.

How does one adjust the aspect ratio for Maple plot? I actually searched for aspect ratio for Maple on google and not able to find much of anything. Help does not have such phrase. May be it called something else in Maple? The reason I ask, is that when I change the size of bode plot, the aspect ratio become bad. So I need a way to adjust that. Here is an example

restart:
alias(DS=DynamicSystems):
sys:=DS:-TransferFunction(5*s/(s^2+4*s+25)):
DS:-BodePlot(sys,range=0.1..100);

Now if I do

DS:-BodePlot(sys,range=0.1..100,size=[300,"default"]);

I am finding so many problems with Bodeplot in Maple, but this is for another time. I think it needs much more polishing

Maple 18, windows 7

Hi all.

Assume that we have:

where

and assume we  want to construct a special Vector as

and from the above vector construct following matrix

how can we do it?

Best wishes

Mahmood   Dadkhah

Ph.D Candidate

Applied Mathematics Department

RandomCompositions:= module()
local
Compositions, Rand,
ModuleApply:= 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
;
end module:
R:= RandomCompositions(8,6):
n:= 3:
S:= 'R()' $ n;
map(lhs=rhs/n, Statistics:-Tally(op~([S])));

[0 = 7/3, 1 = 5/3, 2 = 4/3, 5 = 1/3, 6 = 1/3]

plot([S],x=0..8,style=point);

I have  plot problem .

I want to plot the statistics result,but it runs error.

Hi All,

I'm a new Maple user and I just have a question about evaluating a formula.

Say that you have a formula y=45*r*t

and you know what "r" is, lets say r=5

What do I do if I want to evaluate this formula for the values t=2 all they way up to t=150.

Is there a simple command that lets me do this?

Yours

John.

I am generating polynomials and I want to iterate each term in the polynomial and do something accordingly. I collect the first term. I wish to extract the tuples of 1,1,1 and 2,1,1 out and do some calculations.... Do you know how I could achieve that? Thank you:)

expr1 := mu*(h[1, 1, 1]+h[1, 1, 2]+h[1, 1, 3]+h[1, 1, 4])+J1*(h[1, 1, 1]*h[2, 1, 1]+h[1, 1, 2]*h[2, 1, 2]+h[1, 1, 3]*h[2, 1, 3]+h[1, 1, 4]*h[2, 1, 4])+2*J2*(h[1, 1, 1]*h[1, 1, 3]+h[1, 1, 2]*h[1, 1, 4]+h[1, 1, 3]*h[2, 1, 1]+h[1, 1, 4]*h[2, 1, 4]);
mu (h[1, 1, 1] + h[1, 1, 2] + h[1, 1, 3] + h[1, 1, 4]) + J1 (h[1,

1, 1] h[2, 1, 1] + h[1, 1, 2] h[2, 1, 2]

+ h[1, 1, 3] h[2, 1, 3] + h[1, 1, 4] h[2, 1, 4]) + 2 J2 (h[1,

1, 1] h[1, 1, 3] + h[1, 1, 2] h[1, 1, 4]

+ h[1, 1, 3] h[2, 1, 1] + h[1, 1, 4] h[2, 1, 4])
expand(expr1);
J1 h[1, 1, 1] h[2, 1, 1] + J1 h[1, 1, 2] h[2, 1, 2]

+ J1 h[1, 1, 3] h[2, 1, 3] + J1 h[1, 1, 4] h[2, 1, 4]

+ 2 J2 h[1, 1, 1] h[1, 1, 3] + 2 J2 h[1, 1, 2] h[1, 1, 4]

+ 2 J2 h[1, 1, 3] h[2, 1, 1] + 2 J2 h[1, 1, 4] h[2, 1, 4]

+ mu h[1, 1, 1] + mu h[1, 1, 2] + mu h[1, 1, 3]

+ mu h[1, 1, 4]

I'm taking my first steps with maple and pdsolve, trying to run the example in the maplesoft support page:

http://www.maplesoft.com/support/help/Maple/view.aspx?path=examples/pdsolve_boundaryconditions

which reads

>
> restart; with(PDEtools);
> U := diff_table(u(x, t));
>

and I get a solution that is different from the web page, and when i run

Im using maple 13. Any tips about what's wrong?

regards

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Download hh1.mw

Test_modify.mwGood Morning Everybody,

Can anybody demonstrate how I can convert the output from the procedure into an N X N Matrix depending on the nops from the attached file. Thanks everybody.

Regards,

Moses

with(LinearAlgebra):
a:=Vector([1,2]);
b:=Matrix([[1,2],[1,2]]);

Say if I need a^T * b * a, I will do this:

VectorMatrixMultiply(Transpose(a), b);
VectorMatrixMultiply(%, a);

But this seems too long for such a simple matrix （and vector) computation. I am sure there must be an short way.

What if I need more computation, like

a^T * b * c*d*f*g* a, where c,d,f,g are other 2x2 matrices.
 If I were to use the above command, that'll take a long time to input.

Thanks,

f:=x+y+y;

diff(f,x);
diff(f,y);
diff(f,z);

What I hope to get is a vector with i-th entry being the dervative of f, differentiated w.r.s.t the i-th parameter, like this

Vector([1,1,1]);

Is there a more efficient (built-in) command to do this?

VectorCalculus[diff] does not do what I want.

Thanks,

casper