## Order of display of plots...

I have several plots and I'm using the display procedure,

display(seq(p1[i], i = 1..3), pts1, pts2);

to draw them. I want them to be displayed in the specified order, i.e., pts1 and pts2 should be in the foreground. Unfortunately, the display procedure ignores the order. How to enforce the specified order?

## Speeding Up Solving Equation Numerically...

I am currently running into an issue where the numerical solution to an equation (involving an integral, yes, but the value I am solving for is simly a constant in the integral) is taking significantly longer than I would hope it would to solve. I am solving a similar equation (with a simpler expression) and it is significantly easier to solve, and I am hoping for that kind of speed.

On the last two lines in the attachment, I have two expressions. The penultimate expression is the baseline speed that I would like to match. The last expression is the fsolve I would like to speed up.

Is there any way to numerically speed up the process? I found that when I did tracelast after halting the process, there were HUGE numbers being added and subtracted, multiplied and divided. Not only did this significantly slow down the proecss but it also adds much numerical instability, which I would also like to avoid.

All help would be appreciated.

pole-dragging-mapleprimes.mw

## How can we plot implicit polar equations like r^2=...

Hi, there

How can we plot implicit polar equations like r^2 =5-4cos(theta) in maple13?

Regards

Yegan

## Plot a Vector in 3 dimension...

Aslam-u-Alikum. Hope you will be fine all.  I want to plot the follwing vector in the plan z=0 at time t=0 and A=1

v := `<,>`(VectorCalculus[`-`](VectorCalculus[`*`](VectorCalculus[`*`](VectorCalculus[`*`](A, y), 1/VectorCalculus[`+`](x^2, y^2)), exp(VectorCalculus[`-`](VectorCalculus[`*`](k, t))))), VectorCalculus[`*`](VectorCalculus[`*`](VectorCalculus[`*`](A, x), 1/VectorCalculus[`+`](x^2, y^2)), exp(VectorCalculus[`-`](VectorCalculus[`*`](k, t)))), VectorCalculus[`*`](B, t))

## Customise Virtual Solar System by Yi Xie...

I am trying to alter the Virtual Solar system Maple worksheet of Yi Xie in the way that I added several objects to the eight planets and Pluto (e.g. Hale-Bopp, Sedna, 2012 VP113 etc.) and would like to adjust the array such that when zooming out and the obrit and labels overlap so that it's unreadable anymore (orbits and labels) that I can switch on and off (respectively display/not display) specific parts, e.g. the inner solar system. In the original file a single array was created from 1..18 (including 9 orbital entries and 9 label entries). What I did is to create arrays for each part of the Solar system, e.g. Inner for the planets+Pluto 1..18, an array for Hale-Bopp with an orbital entry and a label entry, so [1,2], and an array with 6 entries for 3 additional objects like Sedna, Planet X and 2012 VP113. As well as the sun, which only has a single entry as there are no orbital elements necessary and one just makes a 3dplot (I did not label it, so just one entry). All arrays are converted into lists in the end and displayed. Here is the code:

> with(linalg);

> with(plots);

> with(plottools);

> P1 := matrix([[cos(omega[j]), -sin(omega[j]), 0], [sin(omega[j]), cos(omega[j]), 0], [0, 0, 1]]); P2 := matrix([[1, 0, 0], [0, cos(i[j]), -sin(i[j])], [0, sin(i[j]), cos(i[j])]]); P3 := matrix([[cos(Omega[j]), -sin(Omega[j]), 0], [sin(Omega[j]), cos(Omega[j]), 0], [0, 0, 1]]);

> A:=matrix([[a[j]*(cos(E[j])-e[j])],[a[j]*sqrt(1-e[j]^2)*sin(E[j])],[0]]);

> R:=multiply(P3,P2,P1);

> B:=multiply(R,A);

> a := [.38709893, .72333199, 1.00000011, 1.52366231, 5.20336301, 9.53707032, 19.19126393, 30.06896348, 39.48168677, 1/0.5454e-2, 268.2509283, 532.7838156, 300];

> e := [.20563069, 0.677323e-2, 0.1671022e-1, 0.9341233e-1, 0.4839266e-1, 0.5415060e-1, 0.4716771e-1, 0.858587e-2, .24880766, .994920, .7005635, .8570973, .1];

> i := [7.00487, 3.39471, 0.5e-4, 1.85061, 1.30530, 2.48446, .76986, 1.76917, 17.14175, 89.5328, 24.01830, 11.92859, 10];

> Omega := [48.33167, 76.68069, -11.26064, 49.57854, 100.55615, 113.71504, 74.22988, 131.72169, 110.30347, 282.1476, 90.88303, 144.53190, 45];

> omega := [77.45645, 131.53298, 102.94719, 336.04084, 14.75385, 92.43194, 170.96424, 44.97135, 224.06676, 130.8038, 293.03200, 311.18311, 150];

> i := map(x→ convert(x, units, deg, rad) end proc, i);

> Omega := map(x→ convert(x, units, deg, rad) end proc, Omega);

> omega := map(x→ convert(x, units, deg, rad) end proc, omega);

> for j to 13 do omega[j] := arcsin(sin(omega[j]-Omega[j])/sin(arccos(sin(i[j])*cos(omega[j]-Omega[j])))) end do;

> x := array(1 .. 13);

> y := array(1 .. 13);

> z := array(1 .. 13);

> for j to 13 do x[j] := B[1, 1]; y[j] := B[2, 1]; z[j] := B[3, 1] end do;

> Sun := array([1]);

> Inner := array(1 .. 18); for j to 9 do Colors := [black, green, blue, red, black, yellow, green, violet, brown, aquamarine, black, black, red]; Linestyle := [solid, solid, solid, solid, solid, solid, solid, solid, solid, longdash, solid, solid, longdash]; Inner[j] := spacecurve([subs(E[j] = E, x[j]), subs(E[j] = E, y[j]), subs(E[j] = E, z[j])], E = 0 .. 2*Pi, color = Colors[j], linestyle = Linestyle[j]) end do;

> Comet := array([1, 2]); if j = 10 then Colors := [aquamarine]; Linestyle := [longdash]; Comet[1] := spacecurve([subs(E[j] = E, x[j]), subs(E[j] = E, y[j]), subs(E[j] = E, z[j])], E = 0 .. 2*Pi, color = Colors[j], linestyle = Linestyle[j]) end if;

> Oort := array(1 .. 6); for j from 11 to 13 do Colors := [black, black, red]; Linestyle := [solid, solid, longdash]; Inner[j] := spacecurve([subs(E[j] = E, x[j]), subs(E[j] = E, y[j]), subs(E[j] = E, z[j])], E = 0 .. 2*Pi, color = Colors[j], linestyle = Linestyle[j]) end do;

> Sun[1] := plot3d(0.1e-1, 0 .. 2*Pi, 0 .. Pi, style = PATCHNOGRID, coords = spherical, color = red);

> Inner[10] := textplot3d([subs(E[1] = 0, x[1]), subs(E[1] = 0, y[1]), subs(E[1] = 0, z[1]), "Mercury"]); Inner[11] := textplot3d([subs(E[2] = 0, x[2]), subs(E[2] = 0, y[2]), subs(E[2] = 0, z[2]), "Venus"]); Inner[12] := textplot3d([subs(E[3] = 0, x[3]), subs(E[3] = 0, y[3]), subs(E[3] = 0, z[3]), "Earth"]); Inner[13] := textplot3d([subs(E[4] = 0, x[4]), subs(E[4] = 0, y[4]), subs(E[4] = 0, z[4]), "Mars"]); Inner[14] := textplot3d([subs(E[5] = 0, x[5]), subs(E[5] = 0, y[5]), subs(E[5] = 0, z[5]), "Jupiter"]); Inner[15] := textplot3d([subs(E[6] = 0, x[6]), subs(E[6] = 0, y[6]), subs(E[6] = 0, z[6]), "Saturn"]); Inner[16] := textplot3d([subs(E[7] = 0, x[7]), subs(E[7] = 0, y[7]), subs(E[7] = 0, z[7]), "Uranus"]); Inner[17] := textplot3d([subs(E[8] = 0, x[8]), subs(E[8] = 0, y[8]), subs(E[8] = 0, z[8]), "Neptune"]); Inner[18] := textplot3d([subs(E[9] = 0, x[9]), subs(E[9] = 0, y[9]), subs(E[9] = 0, z[9]), "Pluto"]); Comet[2] := textplot3d([subs(E[10] = 0, x[10]), subs(E[10] = 0, y[10]), subs(E[10] = 0, z[10]), Hale-Bopp]); Oort[4] := textplot3d([subs(E[11] = 0, x[11]), subs(E[11] = 0, y[11]), subs(E[11] = 0, z[11]), "2012 VP113"]); Oort[5] := textplot3d([subs(E[12] = 0, x[12]), subs(E[12] = 0, y[12]), subs(E[12] = 0, z[12]), "Sedna"]); Oort[6] := textplot3d([subs(E[13] = 0, x[13]), subs(E[13] = 0, y[13]), subs(E[13] = 0, z[13]), "Planet X ?", color = red]);

> Sun1 := convert(Sun, 'list');
> Inner1 := convert(Inner, 'list');
> Comet1 := convert(Comet, 'list');
> Oort1 := convert(Oort, 'list');
> display(Sun1, Inner1, Comet1, Oort1, scaling = CONSTRAINED);

The first error message appears after the if-condition. Can you tell me where I am making a mistake? Beware: when copy paste the code from Maple to Word and from Word in here the colons at the end of lines have changed into semi-colons. Hope this is no problem in executing the code despite the lines being in the same ">..." e.g. where the labels are defined.

## How to copy paste Maple code into a message?...

I can't directly copy Maple code into messages but have to insert into Word first, apply some changes that for better readability and copy it from there via Word-paste. Is there a direct way?

## Incorrect Solution from fsolve...

I have a rather complex expression that I want to find the zero for as a function of two other parameters, i.e. I have a function

Denom := (s,M,g) -> stuff

that I want to find the zero of for a variety of values of M and g. In some cases the solution will be complex, which is entirely acceptable. However, the real part of the solution should never be negative, and yet that is the kind of result I am getting.

As an example (illustrated in the worksheet, when attempting to find the zero for M = 3 and g = 0.2, fsolve gives me s = -6.1 -1.4i. However, when I plot the function with the parameters input already, I can clearly see a zero at s = 9 with no imaginary component. Why won't fsolve find this zero? How can I make it do so?

See the bottom of the attached worksheet for the main problem.

## How can we plot the equation\$r=1/theta\$ in polar c...

Hi there,

How can I plot the equation \$r=1/theta\$ in polar plot in maple13? and in general for plotting \$r=1/(theta-alpha)\$ alpha is constant.?

Any help will be appreciated.

Regards

Yegan

## How leave out entries in an array...

If you define an array with entries from 1..10 and you want to plot these entries but with three different plots, e.g. entry 6 and 7, and again entry 10 shall be plotted separately: plot entries 1,2,3,4,5,8,9 in the same way, but entries 6,7 in a second and entry 10 in a third way. For example with different colors.

Is there a command for this?

## Implicit Crank Nicolson Finite Different Method...

Hye,

Have a good day Sir.

can u help me how to solve my problem using the Implicit Crank Nicolson Finite different Method. I have attached the problem and what I have done in Word file. I have to modify my Equations in order to get the graphs (that is wrong actually). Can you help how to get the graphs by not change the sign of my equations?:(

God Bless you.

## Problem to generate Matrix...

Aslam-u-Alikum. Hope you will be fine. I have some error in the last command of the attached file. I want this type of answer

StressesMultiplication := Matrix(2, 2, {(1, 1) = 7, (1, 2) = 10, (2, 1) = 15, (2, 2) = 22})

n.mw

PhD (Scholar)
Department of Mathematics

## To get value in decimal...

Aslam-u-Alikum. Hope you will be fine. I facing the problem of the last line to the attached program. I need the values of lambda in decimal.

Help.mw

PhD (Scholar)
Department of Mathematics

## Customised plotting...

How do you move plot labels individually? Just click-hold-and-drag does not work.

"A Virtual 3D Solar System": http://www.maplesoft.com/applications/view.aspx?SID=4484&view=html#mapleautobookmark5

How do you color the orbits individually?

## How to ArrayInterpolation using real numbers?...

Hi,

I am trying to interpolate a set of arbitrary numbers including real ones like Pi and plot them using ArrayInterpolate. This does not work. Is there a simple way around this?

Thank you.