hello,

restart:

ODE:=diff(T(z),z$2)+A1*(S-1/L+1/L*exp(-L*z))*diff(T(z),z)+A2*T(z)=0;

bcs:=T(0)=1,T(infinity)=0;

bcs:=T(0)=1,T(A3)=0;

dsolve({ODE,bcs});

where, A1, A2, A3, L, S are all constants.

i get an exact solution but is there any way around to get a more compact solution?

Hi everyone,

restart:with(plots):

lambda1:=(S+sqrt(S^2+4*alpha))/(2);

lambda2:=(S-sqrt(S^2+4*alpha))/(2);

plot3d({lambda1,lambda2}, S=-10..10, alpha=-5..5, contours=50,grid=[100,100]);

plot([subs(alpha=-5,lambda1),subs(alpha=-4,lambda1),subs(alpha=-3,lambda1),subs(alpha=-2,lambda1)

,subs(alpha=-1,lambda1),subs(alpha=-0.5,lambda1),subs(alpha=0.0,lambda1),subs(alpha=0.5,lambda1)

,subs(alpha=1,lambda1),subs(alpha=2,lambda1),subs(alpha=3,lambda1),subs(alpha=4,lambda1)

,subs(alpha=5,lambda1),subs(alpha=-5,lambda2),subs(alpha=-4,lambda2),subs(alpha=-3,lambda2)

,subs(alpha=-2,lambda2),subs(alpha=-1,lambda2),subs(alpha=-0.5,lambda2),subs(alpha=0.0,lambda2)

,subs(alpha=0.5,lambda2),subs(alpha=1,lambda2),subs(alpha=2,lambda2),subs(alpha=3,lambda2)

,subs(alpha=4,lambda2),subs(alpha=5,lambda2)],S=-10...10,axes=box,color=[red,green]);

contourplot({lambda1,lambda2}, S=-10..10, alpha=-5..5, contours=50,grid=[100,100]);

How to minimize the disconnect in the 3d plot and countourplot to get a smooth plot?

Hello everyone,

restart:with(plots):

xNData := ExcelTools:-Import("D:/a.xls"):

L := convert(xNData, listlist);

L := [[1.0, 0.75e-1], [2.0, .1], [3.0, .12], [4.0, .14], [5.0, .16], [6.0, .18], [7.0, .2], [8.0, .22], [9.0, .24], [10.0, .26]]

In the above L for each x we have N. I want to sub a single set of value [x,N] into THE equation NN to get a value for d and repeat the same process for each set of [x,N] to get d.  

NN := -N+(N0B-NB)*(erf((1/2)*x/(sqrt(t)*sqrt(d)))-sqrt(erf((1/2)*alpha/d)))/sqrt(erfc((1/2)*alpha/d))+NB;

alpha:=2*10^(-12):NB:=0.075:N0B:=0.2:t:=360000:

Cheers.

@Care Love, sorry for the trouble. I have edited the question.

a.xls

Hello,

restart:

N := N0-(1/2)*sqrt(2)*sqrt(Pi*Kc/d)*(sum(erfc((1/2)*(L*n+x)/sqrt(d*t))+erfc((1/2)*((n+1)*L-x)/sqrt(d*t)),

n = 0 .. infinity));

N0:=0.2:L:=0.25:Kc:=2*10^(-12):t:=360000:d:=2.010619298*10^(-10):

When I plot N vs x = 0..0.25 then there is no issue

plot(N,x=0..0.25,axes=box);

but when try to use a loop to get the data, Maple cannot evaluate

for x from 0 to 0.25 by 0.01 do

N[x]:=evalf(N0-sqrt(Pi*Kc/(2*d))*sum(((((erfc((n*L+x)/(2*sqrt(d*t))))+erfc(((n+1)*L-x)/(2*sqrt(d*t))))),n=0..infinity)));
end do;

Thanks

Hi,

plot([[F(0,0.8)(y),y,y=0..3],[F(0.1,0.8)(y),y,y=0..3],[F(0.2,0.8)(y),y,y=0..3]],numpoints=25,color=[red,green,blue],view=[-0.3..0.5,0..2.5]);

p1:=%:

data:=plottools:-getdata~([p1]):

dm1:=op([1,-1],data);

              dm1 := Vector(4, {(1) = ` 36 x 2 `*Matrix,

                        (2) = `Data Type: `*float[8], (3) = `Storage: `*rectangular, (4) = `Order: `*Fortran_order})

dm2:=op([2,-1],data);

           dm2 := Vector(4, {(1) = ` 32 x 2 `*Matrix,

                    (2) = `Data Type: `*float[8], (3) = `Storage: `*rectangular, (4) = `Order: `*Fortran_order})

dm3:=op([3,-1],data);

                       dm3 := Vector(4, {(1) = ` 28 x 2 `*Matrix, (2) = `Data Type: `*float[8], (3) = `Storage:                                         `*rectangular, (4) = `Order: `*Fortran_order})

How to combine these three matrices into a single one with four columns (y, F(0,0.8)(y), F(0.1,0.8)(y), F(0.2,0.8)(y) )?

Thanks