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en-us2021 Maplesoft, A Division of Waterloo Maple Inc.Maplesoft Document SystemWed, 27 Oct 2021 09:08:20 GMTWed, 27 Oct 2021 09:08:20 GMTQuestions asked on MaplePrimes that have not yet received an answerhttp://www.mapleprimes.com/images/mapleprimeswhite.jpgMaplePrimes - Unanswered Questions
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How to declare variables local with assign?
https://www.mapleprimes.com/questions/232949-How-To-Declare-Variables-Local-With-Assign?ref=Feed:MaplePrimes:Unanswered Questions
<p>I need to declare a whole set of variables as local. The variable names are generates algorithmically using assign. Like so:</p>
<pre class="prettyprint">
seq(seq(assign(cat(S,i,j)=Vector(datatype=float)),i=1..9),j=1..9);</pre>
<p>Stand-alone, this works and creates all these Vectors for later use. But this:</p>
<pre class="prettyprint">
local seq(seq(assign(cat(S,i,j)=Vector(datatype=float)),i=1..9),j=1..9);</pre>
<p>does not work; I get an "error; '(' unexpected".</p>
<p>I really do not want to type all these by hand... on the other hand, if I do not declare these as local I get 99 warnings about implicit local declaration; not nice.</p>
<p>Is there a way to do this?</p>
<p>Thanks,</p>
<p>M.D.</p>
<p>PS: I do not upload as the one line really is all that is needed. At the lowest level one does not get the implicit-declaration warning, but with "local" it still fails.</p>
<p>I need to declare a whole set of variables as local. The variable names are generates algorithmically using assign. Like so:</p>
<pre class="prettyprint">
seq(seq(assign(cat(S,i,j)=Vector(datatype=float)),i=1..9),j=1..9);</pre>
<p>Stand-alone, this works and creates all these Vectors for later use. But this:</p>
<pre class="prettyprint">
local seq(seq(assign(cat(S,i,j)=Vector(datatype=float)),i=1..9),j=1..9);</pre>
<p>does not work; I get an "error; '(' unexpected".</p>
<p>I really do not want to type all these by hand... on the other hand, if I do not declare these as local I get 99 warnings about implicit local declaration; not nice.</p>
<p>Is there a way to do this?</p>
<p>Thanks,</p>
<p>M.D.</p>
<p>PS: I do not upload as the one line really is all that is needed. At the lowest level one does not get the implicit-declaration warning, but with "local" it still fails.</p>
232949Tue, 26 Oct 2021 23:48:37 ZMac DudeMac DudeHow do I graph this forced spring mass system?
https://www.mapleprimes.com/questions/232948-How-Do-I-Graph-This-Forced-Spring-Mass-System?ref=Feed:MaplePrimes:Unanswered Questions
<p>My forced spring mass system is 4x"+4x'+3x=sin(wt). I calculated my w=w* value that maximizes the amplitude (0.5) and my initial conditions are x(0)=x'(0)=0. I need to graph x(t) when w= w* and when w=w*/2. How am I supposed to input this information into maple to create a graph? </p>
<p>My forced spring mass system is 4x"+4x'+3x=sin(wt). I calculated my w=w* value that maximizes the amplitude (0.5) and my initial conditions are x(0)=x'(0)=0. I need to graph x(t) when w= w* and when w=w*/2. How am I supposed to input this information into maple to create a graph? </p>
232948Tue, 26 Oct 2021 15:22:31 ZVRedlundVRedlundChoice of Branch cuts in HeunC
https://www.mapleprimes.com/questions/232944-Choice-Of-Branch-Cuts-In-HeunC?ref=Feed:MaplePrimes:Unanswered Questions
<p>Hi all,<br>
i'm working with the confluent Heun function (Maple 2019).<br>
Since for the case of an integer coefficient delta or gamma there are two integer Frobenius roots at the regular singularities 0 or 1, there is a logarithmic term in the Frobenius solution at these singularities. So, my question is the following:<br>
When moving around this singularity in the complex plane, the value of the logarithmic term might depend on the choice of the complex logarithm's branch cuts. So, does anybody know just about how HeunC is implemented? Is there sth like a power series solution, which value would in my oppinion depend on this choice of a branch cut?<br>
Or is there another implementation that preserves us from this ambiguity in the case of logarithmic singularities (i.e. integer coefficients in the confluent Heun equation)?<br>
<br>
Many thanks,</p>
<p>Hi all,<br />
i'm working with the confluent Heun function (Maple 2019).<br />
Since for the case of an integer coefficient delta or gamma there are two integer Frobenius roots at the regular singularities 0 or 1, there is a logarithmic term in the Frobenius solution at these singularities. So, my question is the following:<br />
When moving around this singularity in the complex plane, the value of the logarithmic term might depend on the choice of the complex logarithm's branch cuts. So, does anybody know just about how HeunC is implemented? Is there sth like a power series solution, which value would in my oppinion depend on this choice of a branch cut?<br />
Or is there another implementation that preserves us from this ambiguity in the case of logarithmic singularities (i.e. integer coefficients in the confluent Heun equation)?<br />
<br />
Many thanks,</p>
232944Mon, 25 Oct 2021 15:03:29 ZSGDASGDAHow can Maple display an accurate uniform tiling of the hyperbolic Poincare disk?
https://www.mapleprimes.com/questions/232923-How-Can-Maple-Display-An-Accurate-Uniform?ref=Feed:MaplePrimes:Unanswered Questions
<p>This worksheet creates geodesics in the Poincare disk by transformation of a series of circles of diminishing radii in the complex plane.</p>
<p>The intersections of the geodesics are meant to create the first few pentagonal uniform tilings in the Poincare disk.</p>
<p>I do not know the mathematically correct way to create such a display, so the radii of the circles are only a trial and error approximation.</p>
<p>What Maple code will provide the radii of the complex circles which produce an accurate uniform pentagonal tiling?</p>
<p>Is there a better overall strategy for producing uniform tilings of the Poincare disk? </p>
<p><a href="/view.aspx?sf=232923_question/HyperbolicTiling.mw">HyperbolicTiling.mw</a></p>
<p>This worksheet creates geodesics in the Poincare disk by transformation of a series of circles of diminishing radii in the complex plane.</p>
<p>The intersections of the geodesics are meant to create the first few pentagonal uniform tilings in the Poincare disk.</p>
<p>I do not know the mathematically correct way to create such a display, so the radii of the circles are only a trial and error approximation.</p>
<p>What Maple code will provide the radii of the complex circles which produce an accurate uniform pentagonal tiling?</p>
<p>Is there a better overall strategy for producing uniform tilings of the Poincare disk? </p>
<p><a href="/view.aspx?sf=232923_question/HyperbolicTiling.mw">HyperbolicTiling.mw</a></p>
232923Thu, 21 Oct 2021 16:49:22 ZEarlEarlPDE General Solution
https://www.mapleprimes.com/questions/232919-PDE-General-Solution?ref=Feed:MaplePrimes:Unanswered Questions
<p>When I use Solve for a PDE with the option singsol=all, is Maple guaranteeing that I am getting all the solutions, and in partidcular , is it returning the *general* solution(s)? </p>
<p>When I use Solve for a PDE with the option singsol=all, is Maple guaranteeing that I am getting all the solutions, and in partidcular , is it returning the *general* solution(s)? </p>
232919Thu, 21 Oct 2021 00:18:09 Zrl137rl137Finding the Real part of Complex Expression
https://www.mapleprimes.com/questions/232910-Finding-The-Real-Part-Of-Complex-Expression?ref=Feed:MaplePrimes:Unanswered Questions
<p>One of our users asks how they can find the <code>Re ( sqrt(a+I*b))</code> where a, b are real.</p>
<p>They had tried entering the latter as "assume", without any luck. </p>
<p>We told them that it may not be very intuitive, but such expressions can be evaluated by wrapping into evalc which implicitly assumes that free parameters are real-valued:</p>
<pre>
evalc(Re(sqrt(a+I*b)));</pre>
<p>One of our users asks how they can find the <code>Re ( sqrt(a+I*b))</code> where a, b are real.</p>
<p>They had tried entering the latter as "assume", without any luck. </p>
<p>We told them that it may not be very intuitive, but such expressions can be evaluated by wrapping into evalc which implicitly assumes that free parameters are real-valued:</p>
<pre>
evalc(Re(sqrt(a+I*b)));</pre>
232910Mon, 18 Oct 2021 13:55:23 ZTechnicalSupportTechnicalSupport