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DEAR SIR

ANYONE CAN HELP TO COMPUTE TIME IN DSOLVE COMMAND?

restart

with(plots)

Nb := 0.1e-4; Nt := 0.1e-4; Sc := 3.0; Sb := 15; Pe := 1; Bi := .5; Pr := 6.8; c[4] := 0; c[6] := .3; c[8] := .4; k[1] := 0; k[2] := 1; k[3] := 0; Un := .1; M := .5

Eq1 := (101-100*lambda)*(1+c[2]*phi(eta))*(diff(f(eta), `$`(eta, 3)))+(diff(f(eta), `$`(eta, 2)))*(f(eta)+g(eta)+c[2]*(diff(phi(eta), eta)))-(diff(f(eta), eta))^2-M*(diff(f(eta), eta)-k[2])+k[2]+Un*(k[2]-(1/2)*eta*(diff(f(eta), `$`(eta, 2)))-(diff(f(eta), eta))) = 0

(101-100*lambda)*(1+c[2]*phi(eta))*(diff(diff(diff(f(eta), eta), eta), eta))+(diff(diff(f(eta), eta), eta))*(f(eta)+g(eta)+c[2]*(diff(phi(eta), eta)))-(diff(f(eta), eta))^2-.6*(diff(f(eta), eta))+1.6-0.5000000000e-1*eta*(diff(diff(f(eta), eta), eta)) = 0

(1)

Eq2 := (101-100*lambda)*(1+c[2]*phi(eta))*(diff(g(eta), `$`(eta, 3)))+(diff(g(eta), `$`(eta, 2)))*(f(eta)+g(eta)+c[2]*(diff(phi(eta), eta)))-(diff(g(eta), eta))^2-M*(diff(g(eta), eta)-k[2])+k[2]+Un*(k[2]-(1/2)*eta*(diff(g(eta), `$`(eta, 2)))-(diff(g(eta), eta))) = 0

(101-100*lambda)*(1+c[2]*phi(eta))*(diff(diff(diff(g(eta), eta), eta), eta))+(diff(diff(g(eta), eta), eta))*(f(eta)+g(eta)+c[2]*(diff(phi(eta), eta)))-(diff(g(eta), eta))^2-.6*(diff(g(eta), eta))+1.6-0.5000000000e-1*eta*(diff(diff(g(eta), eta), eta)) = 0

(2)

Eq3 := (1+c[4]*phi(eta))*(diff(theta(eta), `$`(eta, 2)))+Pr*(diff(theta(eta), eta))*(f(eta)+g(eta))+Nb*Pr*(diff(theta(eta), eta))*(diff(phi(eta), eta))*(1+c[6]*(2*phi(eta)+1))+Nt*Pr*(diff(theta(eta), eta))^2+c[4]*(diff(theta(eta), eta))*(diff(phi(eta), eta))-(1/2)*Pr*eta*Un*(diff(theta(eta), eta)) = 0

diff(diff(theta(eta), eta), eta)+6.8*(diff(theta(eta), eta))*(f(eta)+g(eta))+0.68e-4*(diff(theta(eta), eta))*(diff(phi(eta), eta))*(1.3+.6*phi(eta))+0.68e-4*(diff(theta(eta), eta))^2-.3400000000*eta*(diff(theta(eta), eta)) = 0

(3)

Eq4 := (1+c[6]*phi(eta))*(diff(phi(eta), `$`(eta, 2)))+Sc*(f(eta)+g(eta))*(diff(phi(eta), eta))+c[6]*(diff(phi(eta), eta))^2+Nt*(diff(theta(eta), `$`(eta, 2)))/Nb-(1/2)*Sc*eta*Un*(diff(phi(eta), eta)) = 0

(1+.3*phi(eta))*(diff(diff(phi(eta), eta), eta))+3.0*(f(eta)+g(eta))*(diff(phi(eta), eta))+.3*(diff(phi(eta), eta))^2+1.000000000*(diff(diff(theta(eta), eta), eta))-.1500000000*eta*(diff(phi(eta), eta)) = 0

(4)

Eq5 := (1+c[8]*phi(eta))*(diff(chi(eta), `$`(eta, 2)))+c[8]*(diff(phi(eta), eta))*(diff(chi(eta), eta))-Pe*(chi(eta)*(diff(phi(eta), `$`(eta, 2)))+(diff(phi(eta), eta))*(diff(chi(eta), eta)))+Sb*(diff(chi(eta), eta))*(f(eta)+g(eta))-(1/2)*Sb*eta*Un*(diff(chi(eta), eta)) = 0

(1+.4*phi(eta))*(diff(diff(chi(eta), eta), eta))-.6*(diff(phi(eta), eta))*(diff(chi(eta), eta))-chi(eta)*(diff(diff(phi(eta), eta), eta))+15*(diff(chi(eta), eta))*(f(eta)+g(eta))-.7500000000*eta*(diff(chi(eta), eta)) = 0

(5)

Vc[2] := [.2, .3, .4]

etainf := 1.85

bcs := (D(f))(0) = k[1], (D(g))(0) = k[3], f(0) = 0, g(0) = 0, (D(theta))(0) = -Bi*(1-theta(0))/(1+c[4]*phi(0)), Nb*(D(phi))(0)*(1+c[6]*(2*phi(0)+1))+Nt*(D(theta))(0) = 0, chi(0) = 1, (D(f))(etainf) = k[2], (D(g))(etainf) = k[2], theta(etainf) = 0, phi(etainf) = 0, chi(etainf) = 0

(D(f))(0) = 0, (D(g))(0) = 0, f(0) = 0, g(0) = 0, (D(theta))(0) = -.5+.5*theta(0), 0.1e-4*(D(phi))(0)*(1.3+.6*phi(0))+0.1e-4*(D(theta))(0) = 0, chi(0) = 1, (D(f))(1.85) = 1, (D(g))(1.85) = 1, theta(1.85) = 0, phi(1.85) = 0, chi(1.85) = 0

(6)

dsys := {Eq1, Eq2, Eq3, Eq4, Eq5, bcs}

for i to 3 do c[2] := Vc[2][i]; dsol[i] := dsolve(dsys, numeric, continuation = lambda); print(c[2]); print(dsol[i](0)) end do

.2

 

[eta = 0., chi(eta) = HFloat(1.0), diff(chi(eta), eta) = HFloat(3.888290578689045), f(eta) = HFloat(0.0), diff(f(eta), eta) = HFloat(0.0), diff(diff(f(eta), eta), eta) = HFloat(2.244199282192492), g(eta) = HFloat(0.0), diff(g(eta), eta) = HFloat(0.0), diff(diff(g(eta), eta), eta) = HFloat(2.244199282192492), phi(eta) = HFloat(-2.044191234673432), diff(phi(eta), eta) = HFloat(5.227515304629519), theta(eta) = HFloat(0.2317093657771352), diff(theta(eta), eta) = HFloat(-0.38414531711143246)]

 

.3

 

[eta = 0., chi(eta) = HFloat(1.0), diff(chi(eta), eta) = HFloat(4.148187853914835), f(eta) = HFloat(0.0), diff(f(eta), eta) = HFloat(0.0), diff(diff(f(eta), eta), eta) = HFloat(3.1086884419918364), g(eta) = HFloat(0.0), diff(g(eta), eta) = HFloat(0.0), diff(diff(g(eta), eta), eta) = HFloat(3.1086884419918364), phi(eta) = HFloat(-2.049332060722701), diff(phi(eta), eta) = HFloat(5.527786294980874), theta(eta) = HFloat(0.2216792480031605), diff(theta(eta), eta) = HFloat(-0.38916037599841974)]

 

.4

 

[eta = 0., chi(eta) = HFloat(0.9999999999999998), diff(chi(eta), eta) = HFloat(4.580796631072469), f(eta) = HFloat(0.0), diff(f(eta), eta) = HFloat(0.0), diff(diff(f(eta), eta), eta) = HFloat(5.687607599246298), g(eta) = HFloat(0.0), diff(g(eta), eta) = HFloat(0.0), diff(diff(g(eta), eta), eta) = HFloat(5.687607599246298), phi(eta) = HFloat(-2.0568809171520708), diff(phi(eta), eta) = HFloat(6.0203396482123575), theta(eta) = HFloat(0.20686299926628238), diff(theta(eta), eta) = HFloat(-0.39656850036685887)]

(7)

NULL

 

 

Download 3DAKc2w_-_Copy.mw

For reference this question was posted exactly 9:05

A simple timing program

st:=time():
for i to 35 do
  i;
end do;
time()-st;

On M16 seems to display after 7 seconds, the time reads 0.010
On M12 it displays in roughly 2 seconds with the time as 0.170

It is physically longer with M16.  Do others get the same results?

**edit add**
No comments?  I should add that it is a laptop 1.4Ghz single core.  Not that it matters but maybe M16 is set up to work more efficiently...

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