Mr. Robert Long

## 1409 Reputation

14 years, 349 days
Leeds, United Kingdom

## Are you hoping to obtain symbolic expres...

Are you hoping to obtain symbolic expressions for Ana, Anm, Anr, Ans, Bna, Bnm, Bno and Bns in terms of n and theta ? Are you interested in numeric solutions for given n and theta ? For example:

`sys:={eq1, eq2, eq3, eq4, eq5, eq6, eq7, eq8};sys_sub:=subs({n=1,theta=0},sys);fsolve(sys_sub, {Ana, Anm, Anr, Ans, Bna, Bnm, Bno, Bns});      {Ana = 2.968328229*10^8, Anm = 1.395157953*10^9, Anr = -5.323482514*10^5,        Ans = -8.950727638*10^8, Bna = 0.7039319912e-2, Bnm = -0.3091044476e-2,        Bno = 1.269538296*10^(-8), Bns = 0.3530504109e-1}`
` `

## ODE definitions are wrong...

T1 and T2 are functions of t, but you differentiate them with respect to x in the ODE definitions.

I'm afraid I've forgotten most of the mechanics I ever learned, so I can't advise on the model, but you might start by simply changing differentiation wrt x, to wrt t.

## A few problems...

Normally when there is no result it means Maple didn't find any solutions.I can see a few problems in your code:

1. Z[0] = 377; should be Z[0] := 377;

2. It's generally not a good idea to use indexed variables such as Z[0] and then also use Z on it own.

3. subs(w = w[1], 2*Z[0]*(1-S[21])/S[21]) doesn't do anything

4. subs(w = w[2], 2*Z[0]*(1-S[21])/S[21]) also doesn't do anything

5. I counted 15 variables before I lost count, but there are only 10 equations

6. Generally, you may find it easier to assign a name to each of the equations on seperate lines, then call solve() with (solve({eq1,eq2,...}) etc

## case sensitive...

I believe your problem is that Maple is case sensitive. Hence this should work:

dsolve({ODE,ics});

## The problem seems to be that indruk...

The problem seems to be that indrukking does not depend on s:

`indrukking;                   /                           2           222.8 - \(152.5 - 108 cos(beta1[1]))                                             2\                    + (-105.6 - 108 sin(beta1[1])) /^(1/2)`
` `
`it seems to depend only on beta1[1] . So:`
` `
`plot(indrukking, beta1[1] = 0 .. 180);`

## If you look at the output of solve(...

If you look at the output of solve(eq,{theta1,theta2}); it is giving you  θ1 =...... and θ2

Of course, as I mentioned above, there are two unknowns are only one equation so θ1 is given in terms of θ2 and vice versa.

If you give a value to one of θ1 or θ2 hen you can solve for the other. For example:

`eq2:=subs(theta1=0,eq);`
`solve(eq2);`

Now you have the problem that there are many solutions since the function is sinusoidal. so you can use fsolve, and restrict the range:

fsolve(eq2, theta2, 0..Pi);

2.431253757

## Need equation(s)...

You don't have any equations, only 4 assignments to variables. I *guess* you want the last assignment to be an equation, so

`Lar := 416:Iar := -45+158*cos(theta1)-416*cos(theta2):Jar := 169+158*theta1-416*sin(theta2):eq := Lar = sqrt(Iar^2-Jar^2):`

However, now you have one equation and two unknowns. You can use solve, but you won't get a unique answer:

`solve(eq,{theta1,theta2});`

## Inconsistent...

In your solve command, you seem to be solving for 10 unknown variables. However, you only have 4 equations: mf2, mf3, mf4 and mf5; while some of the "equations" in your solve command are actually just variable assignments (dm1, dm1A, dm1B, dm1C, dm2, dm2A,  dm2B , dm2C).

I believe it is an instrument that measures the amplitude of a pulse/signal.

http://www.universe.nasa.gov/xrays/programs/astroe/eng/pha-math.html

## normal...

I think it's normal behaviour by Maple.

For example,

`(a*c+c)/(b*c+c);                            a c + c                            -------                            b c + c`

## plot3d...

The plot command is for curves. You have a surface. Does this do what you want ?

plot3d([x(eta,xi),y(eta,xi)],eta = -1..1, xi=-1..1);

## Tools>Assistant>Import Data...

Are you able to import it using the menu ?

Tools>Assistant>Import Data

?

## DirectSearch:-Search()...

The Search command in the DirectSearch package should be able to find the maximum and minimum

http://www.maplesoft.com/applications/view.aspx?SID=101333

As for the mean, you can find this by integration of the function over the volume, divided by the volume of integration.

## L[i]...

Perhaps you need to use L[i] instead of L(i) inside the procedure ?

## I'm not sure if there is an equivalent f...

I'm not sure if there is an equivalent function in Maple, but I think this should work, if I've understood what you want to achieve

`conv:=proc(f1::list,f2::list) # procedure computes the discrete convolution of two lists, returning a list local n, tmp, k, cv: cv:=[]: for n from 1 to nops(f1)+nops(f2)+1 do   tmp:=0:   for k from 1 to nops(f1) do     if n>k and n-k<=nops(f2) then tmp:=tmp+f1[k]*f2[n-k]: end if   end do;   cv:=[op(cv),tmp]: end do:end proc:`
` `
`s1:=[1,2,1,2]:s2:=[1,3,1,2]:conv(s1,s2);                  [0, 1, 5, 8, 9, 11, 4, 4, 0]`
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