I'm trying to create a series of if commands which will return a value based on some initial conditions.  I have 5 equations, x1, x2, x3, x4 and x5, which contain functions containing parameters m and n.

 

If the initial condition is "yes", then x1, x2 and x3 could be used, if no, then only x4 and x5 can be used. 

 

For the "yes" case, if m = 0, then only x2 can be used, and likewise, if n=0, only x3 applies.  Should m > 0, n > 0, then x1 applies.

I've been trying to vreate a script which will provide the roots of the Bessel function of the first kind, and it's derivative.

 

The root of the Bessel itself is fairly straight forward, simply BesselJZero(m,n); however, I can't do the same for the derivative diff(BesselJ(m,n),n).

 

Any help would be appreicated.

Is there a quick way to remove a value corresponding to a given row and column position from within a table?

 

For example, say I wanted the result written out for the 4th column, 3rd row, and all I'd have to do would be enter say row:=3;  column:= 4; and have the data written out.  I've done something before like this in Excel with an IF command, but I can't get it working in Maple.

I'm dealing with an equation of the form shown below:

E-I*(Pi-5)^.5*r*(cos(2*phi)-sin(2*phi))

Basically, I am trying to solve for E in polar co-ordinates, across a radius of r, in a given range of phi = 2*Pi - so, for a given value of r, there would be several values of E around a circle. I was toying with the idea of using the fsolve command to solve for the range of r first, then create a data matrix, then continue solving for phi, but I have no idea how to bridge the gap between the two. Thanks.

I'm using the following bit of code: step1:=1:for w[x] from start by jump to finish do: fsolve(test2,k,complex): answer:=%: k1:=Re(answer[1]): k2:=Im(answer[1]): k3:=Re(answer[2]): k4:=Im(answer[2]): data[step1,1]:=w[x]: data[step1,2]:=k1: data[step1,3]:=k2: data[step1,4]:=k3: data[step1,5]:=k4: step1:=step1+1: end do: Obtain All Data Points from Array points1:=seq([data[d,2],data[d,1]],d=1..nopoints): points2:=seq([data[d,3],data[d,1]],d=1..nopoints): points3:=seq([data[d,4],data[d,1]],d=1..nopoints): points4:=seq([data[d,5],data[d,1]],d=1..nopoints): Obtain Relevant Data Points