Unanswered Questions

This page lists MaplePrimes questions that have not yet received an answer

Please I need Correction on this code particularly if I can make do without the declaration of vector in the third subroutine . The idea is to get maximum error. The code has 3 subroutine. The problem I think is in the third subroutine (Display of results).

Thank you in anticipation of positive response.

# First Declaration of the problem

restart:
Digits:=30:
interface(rtablesize=infinity):

f1:=proc(n)
    y2[n]:
end proc:
f2:=proc(n)
    -y1[n]+0.001*cos(t[n]):
end proc:
f3:=proc(n)
    y4[n]:
end proc:
f4:=proc(n)
    -y3[n]+0.001*sin(t[n]):
end proc:
F1:=proc(n)
    f2(n):
end proc:
F2:=proc(n)
    -(f1(n))-0.001*sin(t[n]):
end proc:
F3:=proc(n)
    f4(n):
end proc:
F4:=proc(n)
    -f3(n)+0.001*cos(t[n]):
end proc:


# Declaration of the Numerical methods

e1:=y1[n+2] = (7/23)*y1[n]+(16/23)*y1[n+1]+(12/23)*f1(n+2)*h+(16/23)*f1(n+1)*h-(2/23)*F1(n+2)*h^2+(2/23)*h*f1(n)+((24/3703)*y1[n]-(24/3703)*y1[n+1]+(48/18515)*f1(n+2)*h+(8/55545)*f1(n+1)*h-(116/55545)*F1(n+2)*h^2+(208/55545)*h*f1(n))*u^2+((901/2980915)*y1[n]-(901/2980915)*y1[n+1]+(7109/89427450)*f1(n+2)*h+(923/14904575)*f1(n+1)*h-(6241/89427450)*F1(n+2)*h^2+(14383/89427450)*h*f1(n))*u^4+((1979723/158376013950)*y1[n]-(1979723/158376013950)*y1[n+1]+(6364571/2375640209250)*f1(n+2)*h+(728327/215967291750)*f1(n+1)*h-(11785633/4751280418500)*F1(n+2)*h^2+(5106559/791880069750)*h*f1(n))*u^6+((6488435581/13259239887894000)*y1[n]-(6488435581/13259239887894000)*y1[n+1]+(8693517709/91794737685420000)*f1(n+2)*h+(260601208141/1789997384865690000)*f1(n+1)*h-(323357994149/3579994769731380000)*F1(n+2)*h^2+(891627999937/3579994769731380000)*h*f1(n))*u^8+((25090513463/1343541160668420000)*y1[n]-(25090513463/1343541160668420000)*y1[n+1]+(190450718149/55421072877572325000)*f1(n+2)*h+(47563947061/8210529315195900000)*f1(n+1)*h-(1475729910283/443368583020578600000)*F1(n+2)*h^2+(261738159769/27710536438786162500)*h*f1(n))*u^10+((244426606265778733/347060946154014557665200000)*y1[n]-(244426606265778733/347060946154014557665200000)*y1[n+1]+(1316372988977975777/10411828384620436729956000000)*f1(n+2)*h+(105391490263288387/473264926573656214998000000)*f1(n+1)*h-(1284959669761615073/10411828384620436729956000000)*F1(n+2)*h^2+(72506125749079249/204153497737655622156000000)*h*f1(n))*u^12:

e2:=h^2*F1(n+1) = (60/23)*y1[n]-(60/23)*y1[n+1]+(25/46)*f1(n+2)*h+(32/23)*f1(n+1)*h-(4/23)*F1(n+2)*h^2+(31/46)*h*f1(n)+((209/3703)*y1[n]-(209/3703)*y1[n+1]+(1313/222180)*f1(n+2)*h+(1304/55545)*f1(n+1)*h-(131/18515)*F1(n+2)*h^2+(6011/222180)*h*f1(n))*u^2+((77491/35770980)*y1[n]-(77491/35770980)*y1[n+1]+(574843/2146258800)*f1(n+2)*h+(113536/134141175)*f1(n+1)*h-(53461/178854900)*F1(n+2)*h^2+(2258041/2146258800)*h*f1(n))*u^4+((151508243/1900512167400)*y1[n]-(151508243/1900512167400)*y1[n+1]+(1290306599/114030730044000)*f1(n+2)*h+(18919693/647901875250)*f1(n+1)*h-(113769323/9502560837000)*F1(n+2)*h^2+(4470322013/114030730044000)*h*f1(n))*u^6+((42120775181/14464625332248000)*y1[n]-(42120775181/14464625332248000)*y1[n+1]+(332746636891/734357901483360000)*f1(n+2)*h+(302396120633/298332897477615000)*f1(n+1)*h-(369019384141/795554393273640000)*F1(n+2)*h^2+(13797329479621/9546652719283680000)*h*f1(n))*u^8+((18953368786273/177347433208231440000)*y1[n]-(18953368786273/177347433208231440000)*y1[n+1]+(2430202319484337/138330997902420523200000)*f1(n+2)*h+(310803544671199/8645687368901282700000)*f1(n+1)*h-(203453960588449/11527583158535043600000)*F1(n+2)*h^2+(7380568619069419/138330997902420523200000)*h*f1(n))*u^10+((16436168060905785763/4164731353848174691982400000)*y1[n]-(16436168060905785763/4164731353848174691982400000)*y1[n+1]+(167160345356705269819/249883881230890481518944000000)*f1(n+2)*h+(461636091223370027/354948694930242161248500000)*f1(n+1)*h-(13852288092290788813/20823656769240873459912000000)*F1(n+2)*h^2+(29059878239787610409/14699051837111204795232000000)*h*f1(n))*u^12:


e3:=y2[n+2] = (7/23)*y2[n]+(16/23)*y2[n+1]+(12/23)*f2(n+2)*h+(16/23)*f2(n+1)*h-(2/23)*F2(n+2)*h^2+(2/23)*h*f2(n)+((24/3703)*y2[n]-(24/3703)*y2[n+1]+(48/18515)*f2(n+2)*h+(8/55545)*f2(n+1)*h-(116/55545)*F2(n+2)*h^2+(208/55545)*h*f2(n))*u^2+((901/2980915)*y2[n]-(901/2980915)*y2[n+1]+(7109/89427450)*f2(n+2)*h+(923/14904575)*f2(n+1)*h-(6241/89427450)*F2(n+2)*h^2+(14383/89427450)*h*f2(n))*u^4+((1979723/158376013950)*y2[n]-(1979723/158376013950)*y2[n+1]+(6364571/2375640209250)*f2(n+2)*h+(728327/215967291750)*f2(n+1)*h-(11785633/4751280418500)*F2(n+2)*h^2+(5106559/791880069750)*h*f2(n))*u^6+((6488435581/13259239887894000)*y2[n]-(6488435581/13259239887894000)*y2[n+1]+(8693517709/91794737685420000)*f2(n+2)*h+(260601208141/1789997384865690000)*f2(n+1)*h-(323357994149/3579994769731380000)*F2(n+2)*h^2+(891627999937/3579994769731380000)*h*f2(n))*u^8+((25090513463/1343541160668420000)*y2[n]-(25090513463/1343541160668420000)*y2[n+1]+(190450718149/55421072877572325000)*f2(n+2)*h+(47563947061/8210529315195900000)*f2(n+1)*h-(1475729910283/443368583020578600000)*F2(n+2)*h^2+(261738159769/27710536438786162500)*h*f2(n))*u^10+((244426606265778733/347060946154014557665200000)*y2[n]-(244426606265778733/347060946154014557665200000)*y2[n+1]+(1316372988977975777/10411828384620436729956000000)*f2(n+2)*h+(105391490263288387/473264926573656214998000000)*f2(n+1)*h-(1284959669761615073/10411828384620436729956000000)*F2(n+2)*h^2+(72506125749079249/204153497737655622156000000)*h*f2(n))*u^12:

e4:=h^2*F2(n+1) = (60/23)*y2[n]-(60/23)*y2[n+1]+(25/46)*f2(n+2)*h+(32/23)*f2(n+1)*h-(4/23)*F2(n+2)*h^2+(31/46)*h*f2(n)+((209/3703)*y2[n]-(209/3703)*y2[n+1]+(1313/222180)*f2(n+2)*h+(1304/55545)*f2(n+1)*h-(131/18515)*F2(n+2)*h^2+(6011/222180)*h*f2(n))*u^2+((77491/35770980)*y2[n]-(77491/35770980)*y2[n+1]+(574843/2146258800)*f2(n+2)*h+(113536/134141175)*f2(n+1)*h-(53461/178854900)*F2(n+2)*h^2+(2258041/2146258800)*h*f2(n))*u^4+((151508243/1900512167400)*y2[n]-(151508243/1900512167400)*y2[n+1]+(1290306599/114030730044000)*f2(n+2)*h+(18919693/647901875250)*f2(n+1)*h-(113769323/9502560837000)*F2(n+2)*h^2+(4470322013/114030730044000)*h*f2(n))*u^6+((42120775181/14464625332248000)*y2[n]-(42120775181/14464625332248000)*y2[n+1]+(332746636891/734357901483360000)*f2(n+2)*h+(302396120633/298332897477615000)*f2(n+1)*h-(369019384141/795554393273640000)*F2(n+2)*h^2+(13797329479621/9546652719283680000)*h*f2(n))*u^8+((18953368786273/177347433208231440000)*y2[n]-(18953368786273/177347433208231440000)*y2[n+1]+(2430202319484337/138330997902420523200000)*f2(n+2)*h+(310803544671199/8645687368901282700000)*f2(n+1)*h-(203453960588449/11527583158535043600000)*F2(n+2)*h^2+(7380568619069419/138330997902420523200000)*h*f2(n))*u^10+((16436168060905785763/4164731353848174691982400000)*y2[n]-(16436168060905785763/4164731353848174691982400000)*y2[n+1]+(167160345356705269819/249883881230890481518944000000)*f2(n+2)*h+(461636091223370027/354948694930242161248500000)*f2(n+1)*h-(13852288092290788813/20823656769240873459912000000)*F2(n+2)*h^2+(29059878239787610409/14699051837111204795232000000)*h*f2(n))*u^12:

e5:=y3[n+2] = (7/23)*y3[n]+(16/23)*y3[n+1]+(12/23)*f3(n+2)*h+(16/23)*f3(n+1)*h-(2/23)*F3(n+2)*h^2+(2/23)*h*f3(n)+((24/3703)*y3[n]-(24/3703)*y3[n+1]+(48/18515)*f3(n+2)*h+(8/55545)*f3(n+1)*h-(116/55545)*F3(n+2)*h^2+(208/55545)*h*f3(n))*u^2+((901/2980915)*y3[n]-(901/2980915)*y3[n+1]+(7109/89427450)*f3(n+2)*h+(923/14904575)*f3(n+1)*h-(6241/89427450)*F3(n+2)*h^2+(14383/89427450)*h*f3(n))*u^4+((1979723/158376013950)*y3[n]-(1979723/158376013950)*y3[n+1]+(6364571/2375640209250)*f3(n+2)*h+(728327/215967291750)*f3(n+1)*h-(11785633/4751280418500)*F3(n+2)*h^2+(5106559/791880069750)*h*f3(n))*u^6+((6488435581/13259239887894000)*y3[n]-(6488435581/13259239887894000)*y3[n+1]+(8693517709/91794737685420000)*f3(n+2)*h+(260601208141/1789997384865690000)*f3(n+1)*h-(323357994149/3579994769731380000)*F3(n+2)*h^2+(891627999937/3579994769731380000)*h*f3(n))*u^8+((25090513463/1343541160668420000)*y3[n]-(25090513463/1343541160668420000)*y3[n+1]+(190450718149/55421072877572325000)*f3(n+2)*h+(47563947061/8210529315195900000)*f3(n+1)*h-(1475729910283/443368583020578600000)*F3(n+2)*h^2+(261738159769/27710536438786162500)*h*f3(n))*u^10+((244426606265778733/347060946154014557665200000)*y3[n]-(244426606265778733/347060946154014557665200000)*y3[n+1]+(1316372988977975777/10411828384620436729956000000)*f3(n+2)*h+(105391490263288387/473264926573656214998000000)*f3(n+1)*h-(1284959669761615073/10411828384620436729956000000)*F3(n+2)*h^2+(72506125749079249/204153497737655622156000000)*h*f3(n))*u^12:
e6:=h^2*F3(n+1) = (60/23)*y3[n]-(60/23)*y3[n+1]+(25/46)*f3(n+2)*h+(32/23)*f3(n+1)*h-(4/23)*F3(n+2)*h^2+(31/46)*h*f3(n)+((209/3703)*y3[n]-(209/3703)*y3[n+1]+(1313/222180)*f3(n+2)*h+(1304/55545)*f3(n+1)*h-(131/18515)*F3(n+2)*h^2+(6011/222180)*h*f3(n))*u^2+((77491/35770980)*y3[n]-(77491/35770980)*y3[n+1]+(574843/2146258800)*f3(n+2)*h+(113536/134141175)*f3(n+1)*h-(53461/178854900)*F3(n+2)*h^2+(2258041/2146258800)*h*f3(n))*u^4+((151508243/1900512167400)*y3[n]-(151508243/1900512167400)*y3[n+1]+(1290306599/114030730044000)*f3(n+2)*h+(18919693/647901875250)*f3(n+1)*h-(113769323/9502560837000)*F3(n+2)*h^2+(4470322013/114030730044000)*h*f3(n))*u^6+((42120775181/14464625332248000)*y3[n]-(42120775181/14464625332248000)*y3[n+1]+(332746636891/734357901483360000)*f3(n+2)*h+(302396120633/298332897477615000)*f3(n+1)*h-(369019384141/795554393273640000)*F3(n+2)*h^2+(13797329479621/9546652719283680000)*h*f3(n))*u^8+((18953368786273/177347433208231440000)*y3[n]-(18953368786273/177347433208231440000)*y3[n+1]+(2430202319484337/138330997902420523200000)*f3(n+2)*h+(310803544671199/8645687368901282700000)*f3(n+1)*h-(203453960588449/11527583158535043600000)*F3(n+2)*h^2+(7380568619069419/138330997902420523200000)*h*f3(n))*u^10+((16436168060905785763/4164731353848174691982400000)*y3[n]-(16436168060905785763/4164731353848174691982400000)*y3[n+1]+(167160345356705269819/249883881230890481518944000000)*f3(n+2)*h+(461636091223370027/354948694930242161248500000)*f3(n+1)*h-(13852288092290788813/20823656769240873459912000000)*F3(n+2)*h^2+(29059878239787610409/14699051837111204795232000000)*h*f3(n))*u^12:

e7:=y4[n+2] = (7/23)*y4[n]+(16/23)*y4[n+1]+(12/23)*f4(n+2)*h+(16/23)*f4(n+1)*h-(2/23)*F4(n+2)*h^2+(2/23)*h*f4(n)+((24/3703)*y4[n]-(24/3703)*y4[n+1]+(48/18515)*f4(n+2)*h+(8/55545)*f4(n+1)*h-(116/55545)*F4(n+2)*h^2+(208/55545)*h*f4(n))*u^2+((901/2980915)*y4[n]-(901/2980915)*y4[n+1]+(7109/89427450)*f4(n+2)*h+(923/14904575)*f4(n+1)*h-(6241/89427450)*F4(n+2)*h^2+(14383/89427450)*h*f4(n))*u^4+((1979723/158376013950)*y4[n]-(1979723/158376013950)*y4[n+1]+(6364571/2375640209250)*f4(n+2)*h+(728327/215967291750)*f4(n+1)*h-(11785633/4751280418500)*F4(n+2)*h^2+(5106559/791880069750)*h*f4(n))*u^6+((6488435581/13259239887894000)*y4[n]-(6488435581/13259239887894000)*y4[n+1]+(8693517709/91794737685420000)*f4(n+2)*h+(260601208141/1789997384865690000)*f4(n+1)*h-(323357994149/3579994769731380000)*F4(n+2)*h^2+(891627999937/3579994769731380000)*h*f4(n))*u^8+((25090513463/1343541160668420000)*y4[n]-(25090513463/1343541160668420000)*y4[n+1]+(190450718149/55421072877572325000)*f4(n+2)*h+(47563947061/8210529315195900000)*f4(n+1)*h-(1475729910283/443368583020578600000)*F4(n+2)*h^2+(261738159769/27710536438786162500)*h*f4(n))*u^10+((244426606265778733/347060946154014557665200000)*y4[n]-(244426606265778733/347060946154014557665200000)*y4[n+1]+(1316372988977975777/10411828384620436729956000000)*f4(n+2)*h+(105391490263288387/473264926573656214998000000)*f4(n+1)*h-(1284959669761615073/10411828384620436729956000000)*F4(n+2)*h^2+(72506125749079249/204153497737655622156000000)*h*f4(n))*u^12:

e8:=h^2*F4(n+1) = (60/23)*y4[n]-(60/23)*y4[n+1]+(25/46)*f4(n+2)*h+(32/23)*f4(n+1)*h-(4/23)*F4(n+2)*h^2+(31/46)*h*f4(n)+((209/3703)*y4[n]-(209/3703)*y4[n+1]+(1313/222180)*f4(n+2)*h+(1304/55545)*f4(n+1)*h-(131/18515)*F4(n+2)*h^2+(6011/222180)*h*f4(n))*u^2+((77491/35770980)*y4[n]-(77491/35770980)*y4[n+1]+(574843/2146258800)*f4(n+2)*h+(113536/134141175)*f4(n+1)*h-(53461/178854900)*F4(n+2)*h^2+(2258041/2146258800)*h*f4(n))*u^4+((151508243/1900512167400)*y4[n]-(151508243/1900512167400)*y4[n+1]+(1290306599/114030730044000)*f4(n+2)*h+(18919693/647901875250)*f4(n+1)*h-(113769323/9502560837000)*F4(n+2)*h^2+(4470322013/114030730044000)*h*f4(n))*u^6+((42120775181/14464625332248000)*y4[n]-(42120775181/14464625332248000)*y4[n+1]+(332746636891/734357901483360000)*f4(n+2)*h+(302396120633/298332897477615000)*f4(n+1)*h-(369019384141/795554393273640000)*F4(n+2)*h^2+(13797329479621/9546652719283680000)*h*f4(n))*u^8+((18953368786273/177347433208231440000)*y4[n]-(18953368786273/177347433208231440000)*y4[n+1]+(2430202319484337/138330997902420523200000)*f4(n+2)*h+(310803544671199/8645687368901282700000)*f4(n+1)*h-(203453960588449/11527583158535043600000)*F4(n+2)*h^2+(7380568619069419/138330997902420523200000)*h*f4(n))*u^10+((16436168060905785763/4164731353848174691982400000)*y4[n]-(16436168060905785763/4164731353848174691982400000)*y4[n+1]+(167160345356705269819/249883881230890481518944000000)*f4(n+2)*h+(461636091223370027/354948694930242161248500000)*f4(n+1)*h-(13852288092290788813/20823656769240873459912000000)*F4(n+2)*h^2+(29059878239787610409/14699051837111204795232000000)*h*f4(n))*u^12:

# Display of the solutions


h:=evalf(Pi/6):

omega:=1.0:
u:=omega*h:
N:=solve(h*p = 12*Pi/6, p):
n:=0:

exy1:= [seq](eval(cos(i)+0.0005*i*sin(i)), i=h..N,h):
exy2:= [seq](eval(-0.9995*sin(i)+0.0005), i=h..N,h):
exy3:= [seq](eval(sin(i)-0.0005*i*cos(i)), i=h..N,h):
exy4:= [seq](eval(0.9995*sin(i)+0.0005*i*sin(i)), i=h..N,h):

iny1:=1:
iny2:=0:
iny3:=0:
iny4:=0.9995:

err1 := Vector(N):
err2 := Vector(N):
c:=1:
inx:=0:
vars := y1[n+1],y1[n+2],y2[n+1],y2[n+2],y3[n+1],y3[n+2],y4[n+1],y4[n+2]:
for j from 0 to 2 do
    x[j]:=inx+j*h:
end do:
printf("%4s%9s%9s%9s%9s%9s%9s%10s%10s%9s%9s%9s%10s\n",
    "h","numy1","numy2","numy3","numy4",
    "exy1","exy2","exy3","exy4",
    "erry1","erry2","erry3","erry4");
    
st := time():
for k from 1 to N/2 do
    param1:=y1[n]=iny1,y2[n]=iny2,y3[n]=iny3,y4[n]=iny4:
    param2:=t[n]=x[0],t[n+1]=x[1],t[n+2]=x[2]:
    
    res:=eval(<vars>, fsolve(eval({e||(1..8)},[param1,param2]),{vars})):
    
    for i from 1 to 2 do
        printf("%5.2f%9.3f%9.3f%9.3f%9.3f %8.5f%10.5f%10.5f%10.5f %8.2g%9.3g%9.3g%8.3g\n",
        h*c,res[i],res[i+2],res[i+4],res[i+6],
        exy1[c],exy2[c],exy3[c],exy4[c],
        abs(res[i]-exy1[c]),abs(res[i+2]-exy2[c]),abs(res[i+4]-exy3[c]),abs(res[i+6]-exy4[c])):

        err1[c] := abs(evalf(res[i]-exy1)):
        err2[c] := abs(evalf(res[i+4]-exy3)):
        c:=c+1:
    end do:
    iny1:=res[2]:
    iny2:=res[4]:
    iny3:=res[6]:
    iny4:=res[8]:
    inx:=x[2]:
    for j from 0 to 2 do
        x[j]:=inx+j*h:
    end do:
end do:
v:=time() - st;
printf("Maximum error is %.13g", max(err1));
printf("Maximum error is %.13g", max(err2));

 

i got some trouble when i tried to build large matrix. in my case, notification error out of bound appear when looping stop at 9 from 24 repeatation. 

and this is my looping command:

the result of the script was:

now i feel so desperate so finish my final project because the error, please help me

Find the set of solutions of each of the linear congruence:

a) x≡3x≡3 (mod 5).

b) 2x≡52x≡5 (mod 9).

Hello I have the following small piece of code.

XMLTools[Print](MathML[Export]('sin(theta)'=0.25));

which exports sin(theta)=.25, how do I force the 0 to display.

 

Also

why does the following fail:

sol:=solve([cot(x)=2,x>=0,x<2*Pi],x,AllSolutions, Explicit);

i tried to solve a nonlinear ode with numerical method but maple can't solve it and this error occur:

Error, (in dsolve/numeric/bvp) initial Newton iteration is not converging

my maple codes are attached below:

numeriacal_sol.mw

can any help me?

Hello,
I need to formulate the follow relationship in proper math symbols:

Differential in A (last days value minus today's) has a tendency to reach the Differential in B (today's)

I though this could be expressed with

AΔ -> BΔ

BUt I guess there are more elegant and mathematically correct ways to do this in Maple?

thank you!
Dave

Hi

I have the transition matrix used in Markov chain

A := Matrix([[alpha, beta, gamma], [delta, epsilon, zeta], [eta, theta, mu]])

I would like to write a system of equations that can be solved  to get a Markov chain  irreducible and aperiodic

All the entries of the transition matrix are in the interval [0,1)

 

Many tanks for any help

for example

func1 := proc(system1)

for i from 1 to 100 do

solve([system1[1], system1[2]],[x,y]);

od:

end proc:

 

func1([diff(y,t) = data[i+t+1], diff(x,t) = data[i+t+1]])

i is depend on the for loop inside a function, but woud like to pass this system into a function with i

this will cause error

how to write better for passing a system as parameter using variable inside a function?

Hi guys,

I've had only a little experience with Maple, but I decided to use it for preliminary frequecy response calculations. The funny thing is, I have already the solution in some way, but I'm too stupid to get it working. I can't see the mistake, however, it should have something to do with the H_n(f) function and the other normalized functions.

NASA has published a nice paper which explains the calculations, however, they have used MathCAD. Anyway, I don't think this should be a problem. Here is the documentation: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070016024.pdf 

The error message is for example for the H_n(f) function:

Warning, expecting only range variable f in expression H__n(f) to be plotted but found name H__n

 

Please help me.

Maple file: calculations.mw

i use optimization package with constraint hello >= 0

Minimize(xx=0, {hello >= 0})

but solution only return the case when hello = 0

how about hello > 0?

i would like to find all possible set of solutions using this constraint

do i need to set upper bound, such as {hello <= 7, hello >=0}

can it return solution when hello = 1.1, 1.2, ...2, 2.1, 2.2, 2.3, ....7

I am looking for a numerical solver for a parabolic PDE (up to 2nd order derivatives but no mixed ones) on the spatio-temporal domain [X x Y x T], either as an external package or as MAPLE code.  

I have coded the method of lines on the domain [X x T] and indeed also used pdsolve as a check for that case. However, pdsolve (numerical) cannot solve the PDEs on the domain [X x Y x T].  The run times and memory requirements for the latter case would of course be significantly greater.  

I am about to code up the method of lines (in MAPLE) on the domain [X x Y x T], but am wondering whether there exist external FORTRAN or C code packages that would be faster if called up in MAPLE and whose results would then be post-pocessed in MAPLE.

Does anyone have any suggestions?

MRB

 

hi--how i can solve following equation?

thanks

 

Eq.mw


Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/Eq.mw .
 

Download Eq.mw

 

I've implemented the optimal taxation model proposed in this paper using Maple.

But it never stops running and get stuck in the last line for integral computation. Any idea of what's wrong with that?

This is the last line:

Here is the full code.


Please help me on this :

restart; with(PDETools), with(plots)

n := .3:

Eq1 := (1-n)*(diff(f(x, y), `$`(y, 3)))+(1+x*cot(x))*f(x, y)*(diff(f(x, y), `$`(y, 2)))-(diff(f(x, y), y))/Da+(diff(f(x, y), y))^2+n*We*(diff(f(x, y), `$`(y, 2)))*(diff(f(x, y), `$`(y, 3)))+sin(x)*(theta(x, y)+phi(x, y))/x = x*((diff(f(x, y), y))*(diff(f(x, y), y, x))+(diff(f(x, y), `$`(y, 2)))*(diff(f(x, y), x))):

Eq2 := (diff(theta(x, y), `$`(y, 2)))/Pr+Nt*(diff(theta(x, y), y))^2/Pr+Nb*(diff(phi(x, y), y))*(diff(theta(x, y), y))/Pr+(1+x*cot(x))*f(x, y)*(diff(theta(x, y), y)) = x*((diff(f(x, y), y))*(diff(theta(x, y), x))+(diff(theta(x, y), y))*(diff(f(x, y), x))):

Eq3 := Nb*(diff(phi(x, y), `$`(y, 2)))/(tau*Pr)+Nt*(diff(theta(x, y), `$`(y, 2)))/(tau*Pr)+(1+x*cot(x))*f(x, y)*(diff(phi(x, y), y)) = x*((diff(f(x, y), y))*(diff(phi(x, y), x))+(diff(phi(x, y), y))*(diff(f(x, y), x))):

ValWe := [0, 5, 10]:

bcs := {Nb*(D[2](phi))(x, 0)+Nt*(D[2](theta))(x, 0) = 0, f(0, y) = ((1/12)*y)^2*(6-8*((1/12)*y)+3*((1/12)*y)^2), f(x, 0) = 0, phi(0, y) = -.5*y, phi(x, 12) = 0, theta(0, y) = (1-(1/12)*y)^2, theta(x, 0) = 1, theta(x, 12) = 0, (D[2](f))(x, 0) = Da^(1/2)*(D[2, 2](f))(x, 0)+Da*(D[2, 2, 2](f))(x, 0), (D[2](f))(x, 12) = 0}:

pdsys := {Eq1, Eq2, Eq3}:

p1 := ans[1]:-plot(theta(x, y), x = 1, color = blue):

plots[display]({p1, p2, p3})

 

``


 

Download untitle_2_(1).mw

Suppose I have a questions that says simplify some random square root

using the algorithm

$radicand=range(10,50,1);
$ques="sqrt($radicand)";
$ques_exact=maple("simplify($ques);");
$ques_ML=maple("f := $ques_exact: XMLTools[Print](MathML[Export](f));");

How do I create an answer field that ONLY allows the student to provide the simplified answer $ques_ML??  How might I provide partial points if they do not simplify (for a classic pythag triangle question for example)?

Thank you

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