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en-us2023 Maplesoft, A Division of Waterloo Maple Inc.Maplesoft Document SystemFri, 24 Mar 2023 22:05:52 GMTFri, 24 Mar 2023 22:05:52 GMTThe questions most recently asked on MaplePrimeshttp://www.mapleprimes.com/images/mapleprimeswhite.jpgMaplePrimes - Newest Questions
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Why the derivative of r_ work in ?examples,physics (Lagrangian for a pendulum) but not in my document
https://www.mapleprimes.com/questions/235997-Why-The-Derivative-Of-R-Work-In-examplesphysics-?ref=Feed:MaplePrimes:New%20Questions
<p>Hi,</p>
<p>I have copied codes from the example of the pendulum to use for a simple case of the motion of a particle in the gravitational field. But when it is time to find v_, I get 0 while in the examples worksheet, it works? I try it in Maple 2022 and 2023 so it is not a question of a version of Maple. It seems that I am missing something. Some help would be appreciated.</p>
<p>Here is my <a href="/view.aspx?sf=235997_question/Example_1.mw">Example_1.mw</a>.</p>
<p>Thank you.</p>
<p>Hi,</p>
<p>I have copied codes from the example of the pendulum to use for a simple case of the motion of a particle in the gravitational field. But when it is time to find v_, I get 0 while in the examples worksheet, it works? I try it in Maple 2022 and 2023 so it is not a question of a version of Maple. It seems that I am missing something. Some help would be appreciated.</p>
<p>Here is my <a href="/view.aspx?sf=235997_question/Example_1.mw">Example_1.mw</a>.</p>
<p>Thank you.</p>
235997Fri, 24 Mar 2023 16:50:29 ZlemelinmlemelinmIs there any command or function for counting the nonzero elements in any row of a matrix?
https://www.mapleprimes.com/questions/235996-Is-There-Any-Command-Or-Function-For?ref=Feed:MaplePrimes:New%20Questions
<p>Hi </p>
<p>I have a question concerning the matrix. Is there any Maple command or function for counting the nonzero elements in any row of a matrix?</p>
<p>Thanks for your help.</p>
<p>Hi </p>
<p>I have a question concerning the matrix. Is there any Maple command or function for counting the nonzero elements in any row of a matrix?</p>
<p>Thanks for your help.</p>
235996Fri, 24 Mar 2023 16:26:13 ZMDDMDDIs there a problem with Maple 2023 and plotting 3D figures?
https://www.mapleprimes.com/questions/235995-Is-There-A-Problem-With-Maple-2023-And?ref=Feed:MaplePrimes:New%20Questions
<p>Hello</p>
<p>I am running Maple 2023 on a mac M1. When I ask Maple to print a document with 3D figures, only the axes come out. 2D figures come out fine. If I do the same thing on Maple 2022 on the same machine, there is no problem at all. </p>
<p><img height="100px" src="/view.aspx?sf=235995_question/Fig_3D_Maple2023.png" width="100px"></p>
<p><img src="/view.aspx?sf=235995_question/Fig_3D_Maple2023.png" style="height: 2px; width: 2px;"> <img height="100px" src="/view.aspx?sf=235995_question/Fig_3D_Maple2022.png" width="100px"></p>
<p>Can any one confirm this problem?</p>
<p>many thanks</p>
<p>Hello</p>
<p>I am running Maple 2023 on a mac M1. When I ask Maple to print a document with 3D figures, only the axes come out. 2D figures come out fine. If I do the same thing on Maple 2022 on the same machine, there is no problem at all. </p>
<p><img height="100px" src="/view.aspx?sf=235995_question/Fig_3D_Maple2023.png" width="100px" /></p>
<p><img src="/view.aspx?sf=235995_question/Fig_3D_Maple2023.png" style="height: 2px; width: 2px;" /> <img height="100px" src="/view.aspx?sf=235995_question/Fig_3D_Maple2022.png" width="100px" /></p>
<p>Can any one confirm this problem?</p>
<p>many thanks</p>
235995Fri, 24 Mar 2023 11:33:50 ZemendesemendesA simple question about sets
https://www.mapleprimes.com/questions/235994-A-Simple-Question-About-Sets?ref=Feed:MaplePrimes:New%20Questions
<p>When we specify a set (a sequence of objects enclosed in curly braces), Maple removes duplicates, since the elements of the set must be unique, that is, they cannot be repeated. See below for 2 examples. With the first example {<strong>a<=b</strong> and <strong>b>=a}</strong>, everything is in order, since they are one and the same. But Maple treats the same equality, written in two ways <strong> {a=b, b=a}</strong> , as different objects. It seems to me that this is not very convenient:</p>
<pre class="prettyprint">
restart;
{a<=b, b>=a}; # OK
{a=b, b=a}; # not OK
is((a=b)=(b=a)); # not OK
</pre>
<p> <img src="/view.aspx?sf=235994_question/1.png" style="height: 80px; width: 150px;"></p>
<p> </p>
<p>When we specify a set (a sequence of objects enclosed in curly braces), Maple removes duplicates, since the elements of the set must be unique, that is, they cannot be repeated. See below for 2 examples. With the first example {<strong>a<=b</strong> and <strong>b>=a}</strong>, everything is in order, since they are one and the same. But Maple treats the same equality, written in two ways <strong> {a=b, b=a}</strong> , as different objects. It seems to me that this is not very convenient:</p>
<pre class="prettyprint">
restart;
{a<=b, b>=a}; # OK
{a=b, b=a}; # not OK
is((a=b)=(b=a)); # not OK
</pre>
<p> <img src="/view.aspx?sf=235994_question/1.png" style="height: 80px; width: 150px;" /></p>
<p> </p>
235994Fri, 24 Mar 2023 09:59:39 ZKitonumKitonumComputing very high genus
https://www.mapleprimes.com/questions/235993-Computing-Very-High-Genus?ref=Feed:MaplePrimes:New%20Questions
<p>Hi,</p>
<p>Would anyone here be interested in helping me with a genus problem and running the following code and letting me know the genus? I do not have Maple and have tried other avenues for help without success; the on-line Magma calculator cannot compute it and Mathematica does not have a genus function. I believe the following is the correct syntax to compute the genus however it may take a while.</p>
<p> </p>
<p>with(algcurves);</p>
<p>f:=2*z^6 + z^7/2 - (5*z^11)/4 + 4*z^22 + (29*z^34)/10 - z^40 - (13*z^43)/2 + w^38*(z^2 - z^7/4) + <br>
w^49*(-z^9 + z^13/4 + 2*z^14) + w^34*((7*z^14)/3 - (3*z^18)/2) + w^47*(z^10/3 + (7*z^11)/4 + (8*z^21)/5) + <br>
w^24*(4*z^8 + (4*z^25)/5 - (3*z^27)/2) + w^9*((-6*z^2)/5 - z^6/2 + (7*z^31)/3) + <br>
w^16*((7*z^21)/3 + (4*z^27)/5 + (4*z^32)/3) + w^18*(-6*z^14 - 2*z^31 - z^33) + w^3*(2*z^17 + (7*z^34)/2) + <br>
w^16*((-3*z^5)/4 - 2*z^36 + z^39/3) + w^50*(-1/3*z^23 - (7*z^40)/2 + z^42) + w^4*((-3*z^30)/2 + (4*z^38)/3 + (8*z^42)/5) + <br>
w^33*(-3*z^4 + (8*z^22)/3 - (8*z^43)/5) + w^16*(-1/4*z^26 - (3*z^41)/4 - z^43) + w^48*((2*z^2)/3 + 6*z^26 + (3*z^43)/5) + <br>
w^49*(2*z^18 + z^36 - 2*z^44) + w^10*((-2*z^11)/5 - (3*z^26)/2 + z^45) + w^40*(-1/2*z^20 - z^29 + z^46) + <br>
w^36*(-4 + 8*z^13 - (7*z^47)/4) + w^14*((7*z^24)/5 - 6*z^32 - 6*z^49) + w^22*(-2*z^27 - (8*z^50)/3) + <br>
w^2*((3*z^10)/5 + (7*z^24)/4 - z^50/4);</p>
<p>genus(f,z,w)</p>
<p>Hi,</p>
<p>Would anyone here be interested in helping me with a genus problem and running the following code and letting me know the genus? I do not have Maple and have tried other avenues for help without success; the on-line Magma calculator cannot compute it and Mathematica does not have a genus function. I believe the following is the correct syntax to compute the genus however it may take a while.</p>
<p> </p>
<p>with(algcurves);</p>
<p>f:=2*z^6 + z^7/2 - (5*z^11)/4 + 4*z^22 + (29*z^34)/10 - z^40 - (13*z^43)/2 + w^38*(z^2 - z^7/4) + <br />
w^49*(-z^9 + z^13/4 + 2*z^14) + w^34*((7*z^14)/3 - (3*z^18)/2) + w^47*(z^10/3 + (7*z^11)/4 + (8*z^21)/5) + <br />
w^24*(4*z^8 + (4*z^25)/5 - (3*z^27)/2) + w^9*((-6*z^2)/5 - z^6/2 + (7*z^31)/3) + <br />
w^16*((7*z^21)/3 + (4*z^27)/5 + (4*z^32)/3) + w^18*(-6*z^14 - 2*z^31 - z^33) + w^3*(2*z^17 + (7*z^34)/2) + <br />
w^16*((-3*z^5)/4 - 2*z^36 + z^39/3) + w^50*(-1/3*z^23 - (7*z^40)/2 + z^42) + w^4*((-3*z^30)/2 + (4*z^38)/3 + (8*z^42)/5) + <br />
w^33*(-3*z^4 + (8*z^22)/3 - (8*z^43)/5) + w^16*(-1/4*z^26 - (3*z^41)/4 - z^43) + w^48*((2*z^2)/3 + 6*z^26 + (3*z^43)/5) + <br />
w^49*(2*z^18 + z^36 - 2*z^44) + w^10*((-2*z^11)/5 - (3*z^26)/2 + z^45) + w^40*(-1/2*z^20 - z^29 + z^46) + <br />
w^36*(-4 + 8*z^13 - (7*z^47)/4) + w^14*((7*z^24)/5 - 6*z^32 - 6*z^49) + w^22*(-2*z^27 - (8*z^50)/3) + <br />
w^2*((3*z^10)/5 + (7*z^24)/4 - z^50/4);</p>
<p>genus(f,z,w)</p>
235993Fri, 24 Mar 2023 09:42:48 ZjackTempletonjackTempletonDifficulty with pdsolve and electromagnetics
https://www.mapleprimes.com/questions/235992-Difficulty-With-Pdsolve-And-Electromagnetics?ref=Feed:MaplePrimes:New%20Questions
<p><a href="/view.aspx?sf=235992_question/perturb_mag_current_density_2.mw">perturb_mag_current_density_2.mw</a></p>
<p>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:</p>
<p>Laplacian * E = Div(E) -Curl(Curl(E))</p>
<p>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.</p>
<p>My boundary conditions are simply that the components of the electric field at the surface of the cantilever is always tangent to the surface.</p>
<p>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.</p>
<p>My question: Are my PDEs and BCs sensible? And if so, what do I need to do with pdsolve to get a proper solution?</p>
<p><a href="/view.aspx?sf=235992_question/perturb_mag_current_density_2.mw">perturb_mag_current_density_2.mw</a></p>
<p>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:</p>
<p>Laplacian * E = Div(E) -Curl(Curl(E))</p>
<p>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.</p>
<p>My boundary conditions are simply that the components of the electric field at the surface of the cantilever is always tangent to the surface.</p>
<p>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.</p>
<p>My question: Are my PDEs and BCs sensible? And if so, what do I need to do with pdsolve to get a proper solution?</p>
235992Thu, 23 Mar 2023 19:45:10 Zjbromelljbromell