## Interpolate Polar Coordinates...

Hello,

How do I interpolate using polar coordinates?  I have a series with non-uniform spacing, that I want to map onto a uniform space polar grid.

Any assistance would be appreciated.

## solve system symbolic...

Hello every one,

I had a 3 equations with 3 unknown (X,Y,Z, conjugate(Y),conjugate(Z))

this is the code:

solve( {ao*x + a1*y + conjugate(a1)*conjugate(y)+a2*z+conjugate(a2)*conjugate(z) = 0.5, conjugate(a1)*x + bo*y + conjugate(a2)*conjugate(y)+a1*z = 0, 10*x + 10*y/4 + 10*z = 10}, {x, y, z});

where the coefficients are complex numbers

Is thee any simple way to solve it

thanks

## Exporting Contourplot with higher resolution then ...

Hi experts,

the standard resolution for maple contourplots is 72 dpi wich is not suitable for publication purposes. I need at least a resolution between 500 - 1000 dpi. How do I get better resolutions for my contourplots when exporting them to .bmp or .jpg-files?
Somebody any ideas?

## Vector math and conditional functions...

Level: Idiot (Me)

I have a matrix of 3 columns and lots of rows M

• First column is latitude in degrees
• Second column is longitude in degrees
• Third column is data

So I set lambda:=M(..,1) and phi_g:=M(..,2) giving me two column vectors.

I want to convert lambda and phi_g to polar coordinates theta and phi

theta:=90-lambda produces "Error, (in rtable/Sum) invalid arguments"

WHY?

I also want to convert phi_g to phi where phi=phi_g when phi_g is 0...180 and phi=phi_g +360 when phi_g <0

How do I create a conditional function like this?

## export plot as gif file empty...

i am trying to export an animated gif file but the export windows freezes and exports an empty file with zero bytes

the animation was created by: display(map(p, convert(A(() .. (), 2), list)), insequence = true)

i have tried to give maple some time (2-3 hours) and i even tried to restart the computer and lauch maple and try to export it but it didnt worked

how can i export it or how can i plot the using commands

## how to convert a ODE/DAE system to a real system...

I am using Maple 15 to numerically solve a system of differential algebraic euqations (DAE) with given initial conditions, and I've tried rfk45_dae and rosenbrock_dae solver, but both solver responded in error like this

Error, (in dsolve/numeric) cannot numerically solve complex DAE initial value problems, the system must be converted to a real system

I don't understand what is a real system, and how could i convert it to a real system.

## how to solve differential equations with variables...

i am using maple to solve a system of ordinary differential equations , 3 unknows (x,y, x ), and 3 equations (dx/dt,dy/dt,dz/dt)

there is one known variable denpendent on x and z

# code begins here

if x(t) <= z(t) then Q(t) := 8 end if;

if x(t) > z(t) then Q(t) := 10 end if;

eq1 := diff(x(t), t) = 3*x(t)-1;

eq2 := diff(y(t), t) = y(t)+Q(t);

eq3 := diff(z(t), t) = z(t);

eqs := {eq1, eq2, eq3};

# code ends here

above i put the system of ODEs, the code maybe illegal in maple, but i wrote in this way to make it clear.

Q is dependent on x and z.

in the past, when i was trying to solve ODEs, normally, eqs contains with only x,y,z as unknowns. but in this eqs, clearly, Q is included as an unknown.

i've tried to use piecewise function to express Q(t), but failed.

how could i solve a system like this? thanks

## 1D heat equation with Neumann B.C....

Hello! I have written a code to solve 1D heat equation with Neumann B.C. using explicit method. But there is a problem with plot. I don't understant, what's wrong. Help me, please. I will be very grateful. The code is attached here.
pr3.mw
11.pdf

## fitting multiple data curves...

i have a non linear equation that depends on three variables e, theta and z.

i have done calculations to calculate e while varying theta and z. theta varied among the vector [0, Pi/4, Pi/3, Pi/2] and z was varying between 1 and 20

when plotting my data it gives the following plot where z is represented on the x-axis and each curve correspond to one theta

i am currently able of fitting one plot to one equation i would like to fit the data points using the nonlinearfit function and to only get one equation for all the plots. is that possible in maple or not

## Substitution with mod function doesn't work...

Help!!

Why do the first two of the following 4 examples not work in Maple 15?

subs(m=21,`mod`(m, 4));
subs(m=21,m mod(4));
21
21
`mod`(21, 4);
21 mod(4);

1
1
Is there a (simple) workaround?

Thanks.

## How do import a table of data into a time series?...

I have a table of data arranged in the following columns: Year, Jan, Feb, Mar,..,Dec in Excel or csv

I would like to import this data into a time series in Maple so I can plot the result.

What is the simplest way of doing this?

## Another question about the Physics package...

Here is a problem I have with the Nabla operator:

I am working on a demonstration involving Maxwell's equations:

restart:with(Physics[Vectors]);
Setup(mathematicalnotation = true);
# Maxwell's eqn
M4 := `&x`(Nabla, B1_(x, y, z, t)) = mu*epsilon*(diff(E1_(x, y, z, t), t));

eval(subs(B1_(x,y,z,t)=Bxx(x,y,z,t)*_i+Bzz(x,y,z,t)*_k,M4)); # transverse magnetic field, no longitudinal (j) component

# Ok, this one is as expected.

eval(subs(B1_(x,y,z,t)=Bxx(x,y,z,t)*_i+Bzz(x,y,z,t)*_k,M4)) assuming real;

# Hmm... why is this zero?

eval assuming real seems to make them all zero. In this little example, Bxx and Bzz are just arbitrary functions and therefore the result cannot be zero in general. The bother here is that I later use a parametrization of the field (the Bxx and Bzz) which in fact does make curl(B) = 0. I wanted Maple to demonstrate that the parametrization does that, but it appears i can make the result zero for any B-field, which sort-of defeats the purpose. If I don't assume real, with the other parametrization Maple isn't getting anywhere...

So, how can I get correct results while declaring variables to be real when they are... ?

Thanks,

M.D.

Maxwell_test.mw

## How cant i use collect in this case?...

Plz help me friends ...

I gave this function ...

fuction_A.docx

i wanna extract coeffitions from this function ... for example what is the coeffition of phi(X)*psi(x)?

i used coeff ... but it had an error ..

unable compute coeff ...

i used collect ... but it had an error

what am i doing with this problem?

:(

## Maple 15 on Windows and Ubuntu in a dual boot syst...

Hello,

Is it possible to use Maple 15 Student Edition with the same license information and purchase code both on Windows and Ubuntu?

I did a few Windows reinstalls (guess about 3) hence I used the same purchase code to activate the license that many times. Today I tried installing and using Maple 15 on Ubuntu 12.04.3 LTS 32-bit and to my dismay the license manager said, "Not enough activations left on this account." Furthermore, I have exhausted my download links and would like to know how many times Maple 15 can be activated and if the download links can be refreshed?

Thanks

## What's up with inttrans[fourier]?...

I am trying to get a Fourier transform of a Gaussian:

so I say

and get

The Fouriertransform of a Gaussian is well known and the result I expect is something like

exp(1/2*sigma^2*omega^2)

ignoring normalizations & other factors. I know that I can add functions to inttrans, but I kind-of expected inttrans[fourier] to know how to transform a Gaussian, it is a commonly used transformation. Even if I set phi0 to 0 it does not produce anything useful.

???

Mac Dude

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