## How do I access the Google Maps and Geocoding pack...

Good day!

I attempted to download the geocoding package for Maple and I cannot get it to work. Executing the worksheet produces no results.

I am using Maple 2022.

Can anyone shed some light on this please?

Thanks for reading ..

## How to extract the coefficients of the random var...

How to use collect() or coeffs() on random variables instead of standard variables?

I need to re-organize a linear combination of RVs nu[1], nu[2], u[1], u[2], u[3] by collecting the coefficients on each of these 5 RVs. Note that the Xs are correlated with each other and the Ys are correlated with each other (but Xs and Ys are uncorrelated).

For example, nu is a 2D gaussian vector where nu[1] and nu[2] are defined in terms of _R1, _R2, means, standard deviations and correlation coefficient. They are quite "nested" and the 3D gaussian vector u is even worse, so when these enter a linear combination it becomes hard to identify them back as simply nu[1], nu[2], u[1], u[2], u[3].

Is there a way to "isolate" them in a linear combination by using collect()-like or coeffs()-like functions (i) directly on the RVs or (ii) indireclty on the explicit expressions of _Rs, means, standard devs, correlation coeffs?

(I already checked the answers to these two somewhat similar questions but did not help for my case:

https://mapleprimes.com/questions/235215-Reduce-Length-Of-Sum-Of-Products

https://mapleprimes.com/questions/234292-Re-How-To-Collect-Using-A-Term-By-Multiplication

)

See my script below:

For example, I would want collect() on nu[1] (or equivalently on _R1*sigma__v[1]+nu__0[1]) to give me X__1+X__3 (as you easily see from my definition of Omega).

 > # 2.2.1 Define the Omega random variable as Omega__1+Omega__2+Omega__3:
 >
 (1)
 > # 2.2.2 Simplify and re-arrange the Omega RV to obtain the easy-to-read version (a,b,c,d,e,f are the coefficients): #Omega__* = a + b*nu[1] + c*nu[2] + d*u[1] + e*u[2] + f*u[3]; # How to do it? Collect() does not work...simplify() doesn't make it any easier...
 >
 >
 >

## How to find a symbolic solution for this piecewise...

I can derive a symbolic solution by hand for the following ODE, but cannot get Maple to do it for me.  Any tricks?

 > restart;

Velocity field, ,  .

 > v := (x,t) -> piecewise(x <= -t, 0, x < t, 1 - 1/2*(1 - x/t));

Position :

 > de := diff(x(t),t) = v(x(t),t);

Initial condition, assuming

 > ic := x(0) = -a;

Symbolic solution, calculated by hand:

 > x__exact := t -> piecewise(t < a, -a, t - 2*sqrt(t)*sqrt(a));

Verify exact solution by comparing it against the numeric solution for some :

 > a := 3;  # any a>0 should do dsol := dsolve({de,ic}, numeric): plots:-odeplot(dsol, t=0..5);   # dsolve solution plot(x__exact(t), t=0..5);      # symbolic solution (calculated by hand) a := 'a';

Can Maple's dsolve find the exact solution?  This one returns empty in Maple 2022:

 > dsolve({de, ic}) assuming a > 0, t > 0;

## Rearrange the rows and columns of a square matrix...

I obtain the adjacency matrix from a graph. We know that it is indexed according to the order of vertices in the `Vertices`. But what if I want to rearrange it in a different order? Here is a specific example.

```with(GraphTheory):
g:=Graph({{2,3},{1,2}});
Vertices(g); #[1,2,3]
```

I would like to display this matrix in the order of `[3, 1, 2]`.

## The program is making intercept zero even though T...

I have give this below fit command my data is only continous data either positive or negative float data. Their never any complex number at all.

I use the below fit command

Error, complex argument to max/min

It can be observed it is running into error in C1 I dont know why can someone suggest where should I check and why is this happening kind help.   In Excel we can see the intercept coming big.

I attach the toycode to see the error I get too

toycode.mw

## contourplot3d. For the "coloring=[lowColor, highColor...

by: Maple 2022

# countourplot3d piggybacks on top of plot3d.
# For the "coloring=[lowColor, highColor]", the "filledregions=true" option must be present.
# If "filledregions=true" is not present, plot3d will throw an error.
# This code shows the three cases, only one of which will work.
Note to support. I cannot add a new tag. contourplot3d should be a tag.

restart;
with(plots);
with(ColorTools);
cGr4s := Color([0.50, 0.50, 0.50]);
contourplot3d(-5*d/(d^2 + y^2 + 1), d = -3 .. 3, y = -3 .. 3, color = black, thickness = 3, coloring = [cGr4s, cGr4s], contours = [-2, -1.5, -1, -0.5, 0, 0.5, 1, 1.5, 2]);
contourplot3d(-5*d/(d^2 + y^2 + 1), d = -3 .. 3, y = -3 .. 3, filledregions = false, color = black, thickness = 3, coloring = [cGr4s, cGr4s], contours = [-2, -1.5, -1, -0.5, 0, 0.5, 1, 1.5, 2]);
contourplot3d(-5*d/(d^2 + y^2 + 1), d = -3 .. 3, y = -3 .. 3, filledregions = true, color = black, thickness = 3, coloring = [cGr4s, cGr4s], contours = [-2, -1.5, -1, -0.5, 0, 0.5, 1, 1.5, 2]);

## Check if a symmetric bivariate polynomial has a ro...

I'm having a symmetric bivariate polynomial P(x,y) with a high degree (larger than 8). I want to know if there exists a root of P(x,y) or not. I may not need a specific root but rather to know if P(x,y) has a root or not. I've been doing some research but I only find the command that helps solve univariate functions or solve systems of bivariate functions.

In conclusion, my question is: How can I know that a symmetric bivariate polynomial has a root or not using Maple?

Here is the polynomial I want to check

P(x,y)=x^12*y^3 + 10*x^11*y^4 + 43*x^10*y^5 + 105*x^9*y^6 + 161*x^8*y^7 + 161*x^7*y^8 + 105*x^6*y^9 + 43*x^5*y^10 + 10*x^4*y^11 + x^3*y^12 - x^12*y^2 - 8*x^11*y^3 - 17*x^10*y^4 + 8*x^9*y^5 + 82*x^8*y^6 + 128*x^7*y^7 + 82*x^6*y^8 + 8*x^5*y^9 - 17*x^4*y^10 - 8*x^3*y^11 - x^2*y^12 - x^12*y - 4*x^11*y^2 - 62*x^10*y^3 - 341*x^9*y^4 - 902*x^8*y^5 - 1410*x^7*y^6 - 1410*x^6*y^7 - 902*x^5*y^8 - 341*x^4*y^9 - 62*x^3*y^10 - 4*x^2*y^11 - x*y^12 + x^12 - 8*x^11*y - 62*x^10*y^2 - 680*x^9*y^3 - 3169*x^8*y^4 - 7312*x^7*y^5 - 9540*x^6*y^6 - 7312*x^5*y^7 - 3169*x^4*y^8 - 680*x^3*y^9 - 62*x^2*y^10 - 8*x*y^11 + y^12 + 10*x^11 - 17*x^10*y - 341*x^9*y^2 - 3169*x^8*y^3 - 11838*x^7*y^4 - 21793*x^6*y^5 - 21793*x^5*y^6 - 11838*x^4*y^7 - 3169*x^3*y^8 - 341*x^2*y^9 - 17*x*y^10 + 10*y^11 + 43*x^10 + 8*x^9*y - 902*x^8*y^2 - 7312*x^7*y^3 - 21793*x^6*y^4 - 30696*x^5*y^5 - 21793*x^4*y^6 - 7312*x^3*y^7 - 902*x^2*y^8 + 8*x*y^9 + 43*y^10 + 105*x^9 + 82*x^8*y - 1410*x^7*y^2 - 9540*x^6*y^3 - 21793*x^5*y^4 - 21793*x^4*y^5 - 9540*x^3*y^6 - 1410*x^2*y^7 + 82*x*y^8 + 105*y^9 + 161*x^8 + 128*x^7*y - 1410*x^6*y^2 - 7312*x^5*y^3 - 11838*x^4*y^4 - 7312*x^3*y^5 - 1410*x^2*y^6 + 128*x*y^7 + 161*y^8 + 161*x^7 + 82*x^6*y - 902*x^5*y^2 - 3169*x^4*y^3 - 3169*x^3*y^4 - 902*x^2*y^5 + 82*x*y^6 + 161*y^7 + 105*x^6 + 8*x^5*y - 341*x^4*y^2 - 680*x^3*y^3 - 341*x^2*y^4 + 8*x*y^5 + 105*y^6 + 43*x^5 - 17*x^4*y - 62*x^3*y^2 - 62*x^2*y^3 - 17*x*y^4 + 43*y^5 + 10*x^4 - 8*x^3*y - 4*x^2*y^2 - 8*x*y^3 + 10*y^4 + x^3 - x^2*y - x*y^2 + y^3

## Choose a function from set of user defined functio...

Say I have 20 userdefined functions defined by me say

Now i required function which picks one of the userdefined from the above 20 functions randomly

## Help!! My maple file got corrupted....

Can anyone help me fix a corrupted maple file?

I have tried to fix it myself and searched all over for a solution but can' seem to fix it myself. Please help

## How to optimize an expression with conditional mea...

Hello everyone,

Here is a stylized version of my problem. Given three normally distributed random variables {A, B, C}, I want to find the X_1, X_2, X_3 that maximize the following expression (gamma being a constant and A being a linear combination of other normally distributed random variables):

Max{ Exp[A|B,C] - (gamma/2)*Var[A|B,C] }

All the details are here: 070423_Optimization.mw

In particular, I am seeking your help to:

1. Correlate three random variables (an example of the procedure for correlating two random variables is already provided in the script).
2. Verify my understanding of the linear projection theorem (https://stats.stackexchange.com/questions/30588/deriving-the-conditional-distributions-of-a-multivariate-normal-distribution) in two dimensions, that is, to compute conditional means and variances of the form E[X|Y,Z] and V[X|Y,Z].
3. Implement and adapt the linear projection theorem to my problem in Maple.
4. Combine all together to obtain Expr = E[A|B,C] + V[A|B,C] and find the optimal {X_1, X_2, X_3} by solving the linear system of three equations in the three variables {X_1, X_2, X_3}, where the three equations are obtained by setting to 0 the partial derivatives of Expr with respect to {X_1, X_2, X_3}.

In relation to point 2., did I correctly interpret the matrix form of the three-dimensions version of the linear projection theorem?

In relation to point 3., I attach a stylized script for the three-dimensions version (note that I need the two-dimensions version for my problem): LinearProjectionTheorem_3dimensions.mw. Assuming a correct interpretation of the theorem:

• Did I correctly implement E[X_2|Y_1,Y_2,Y_3] and E[X_3|Y_1,Y_2,Y_3] as in the picture above?
• How to adapt it accordingly to include E[X_1|Y_1,Y_2,Y_3] and V[X_1|Y_1,Y_2,Y_3], V[X_2|Y_1,Y_2,Y_3], and V[X_3|Y_1,Y_2,Y_3]?
• How to apply it to the random variables in my script to eventually find the optimal {X_1,X_2,X_3}?

You can play around with my script 070423_Optimization.mw and send me the updated version. The problem I am trying to solve is quite convoluted, so let me know if you need any further clarification. Thanks a lot!

## what is the correct way to define a function with ...

Actually, I have two questions here, I don't know if they are connected.

I don't know if it's the right way to deifne function with indexed variables, is there any difference between f and g?

I assume they are the same since neither of them work with Maximize.

Finally, I use the most original way in (5), why give the wrong answer? (no way the answer is -infinity)

 (1)

 (2)

 (3)

 (4)

 (5)

## How often does 2022.1 gets updated?...

In the last two months I've have been asked to download an update to 2022.1 around 7 times.

Each oupdates takes 5-10 minutes and I have to sit idle.

1. Is this the typical pace of updates?

2.Is there a veriosn 2023 I need to get? if yes, how?

Thanks!

## corrupt worksheet...

yeah sorry it didnt want 2 send so i spamed the botten i didnt meen 2 send more than 1

it could be amazing if u could help

ty for the quick respons

alle-maple_3.mw

## curve fitting with least square to logistic equati...

i want  your solution  procedure in Maple and get the best fit for the coefficients, r anda k.  i want
plot the data and the y curve together on the same graph to visualize the fitting. For the
data  use blue circles while for the y curve, use red solid line style. Use the leastsquare. thank you verymuch

estimasi_par_logistik.mw

## Difficulty with pdsolve and electromagnetics...

perturb_mag_current_density_2.mw

I am trying to calculate the electric field E induced in a vibrating cantilever of conductive material, oscillating in the field of a permanent magnet.  However, I am having some difficulty getting pdsolve to work the way I want it to.  I'm also not sure if the partial differential eqations I derived from Maxwell's equations are correct, or if the boundary conditions for the electric field in the cantilever are correct.  Currently pdsolve gives me no solutions, which makes me think that either my PDEs or my BCs are not correct.  It may be that I need to try some sort of numerical method as well.  I am assuming that the z component of the electric field is just 0.  My third PDE comes from setting the divergence of the electric field to 0.  My first two PDEs come from the vector laplacian and its relation to the divergence and curl:

Laplacian * E = Div(E) -Curl(Curl(E))

The x and y components of this should be my first and second PDE, respectively.  Note that in this equation the divergence of E is 0, and the curl of E is -dB/dt, where B is the magnetic field.

My boundary conditions are simply that the components of the electric field at the surface of the cantilever is always tangent to the surface.

I have tried various simplifications, such as setting the right hand side of the PDEs to 0, and still I don't get any solution.

My question:  Are my PDEs and BCs sensible?  And if so, what do I need to do with pdsolve to get a proper solution?

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