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en-us2014 Maplesoft, A Division of Waterloo Maple Inc.Maplesoft Document SystemMon, 22 Sep 2014 02:12:29 GMTMon, 22 Sep 2014 02:12:29 GMTMaple 16 Questions and Posts on MaplePrimeshttp://www.mapleprimes.com/images/mapleprimeswhite.jpgMaplePrimes - Maple 16 Posts and Questions
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Fsolve and Isolate Missing Solutions
http://www.mapleprimes.com/questions/202376-Fsolve-And-Isolate-Missing-Solutions?ref=Feed:MaplePrimes:Version Maple 16
<p>To motivate some ideas in my research, I've been looking at the expected number of real roots of random polynomials (and their derivatives). In doing so I have noticed an issue/bug with<strong> fsolve</strong> and <strong>RootFinding[Isolate]</strong>. One of the polynomials I came upon was</p>
<p>f(x) = -32829/50000-(9277/50000)*x-(37251/20000)*x^2-(6101/6250)*x^3-(47777/20000)*x^4+(291213/50000)*x^5.</p>
<p>We know that f(x) has at least 1 real root and, in fact, graphing shows that f(x) has exactly 1 real root (~1.018). However, <strong>fsolve(f)</strong> and <strong>Isolate(f)</strong> both return no real roots. On the other hand, <strong>Isolate(f,method=RC)</strong> correctly returns the root near 1.018. I know that <strong>fsolve</strong>'s details page says "It may not return all roots for exceptionally ill-conditioned polynomials", though this system does not seem especially ill-conditioned. Moreover, <strong>Isolate</strong>'s help page says confidently "All significant digits returned by the program are correct, and <em>unlike purely numerical methods no roots are ever lost</em>, although repeated roots are discarded" which is clearly not the case here. It also seems interesting that the <strong>RealSolving</strong> package used by <strong>Isolate(f,method=RS)</strong> (default method) misses the root while the <strong>RegularChains</strong> package used by <strong>Isolate(f,method=RC)</strong> correctly finds the root.</p>
<p> All-in-all, I am not sure what to make of this. Is this an issue which has been fixed in more recent incarnations of <strong>fsolve</strong> or <strong>Isolate</strong>? Is this a persistent problem? Is there a theoretical reason why the root is being missed, particularly for <strong>Isolate</strong>?<br><br>Any help or insight would be greatly appreciated.</p><p>To motivate some ideas in my research, I've been looking at the expected number of real roots of random polynomials (and their derivatives). In doing so I have noticed an issue/bug with<strong> fsolve</strong> and <strong>RootFinding[Isolate]</strong>. One of the polynomials I came upon was</p>
<p>f(x) = -32829/50000-(9277/50000)*x-(37251/20000)*x^2-(6101/6250)*x^3-(47777/20000)*x^4+(291213/50000)*x^5.</p>
<p>We know that f(x) has at least 1 real root and, in fact, graphing shows that f(x) has exactly 1 real root (~1.018). However, <strong>fsolve(f)</strong> and <strong>Isolate(f)</strong> both return no real roots. On the other hand, <strong>Isolate(f,method=RC)</strong> correctly returns the root near 1.018. I know that <strong>fsolve</strong>'s details page says "It may not return all roots for exceptionally ill-conditioned polynomials", though this system does not seem especially ill-conditioned. Moreover, <strong>Isolate</strong>'s help page says confidently "All significant digits returned by the program are correct, and <em>unlike purely numerical methods no roots are ever lost</em>, although repeated roots are discarded" which is clearly not the case here. It also seems interesting that the <strong>RealSolving</strong> package used by <strong>Isolate(f,method=RS)</strong> (default method) misses the root while the <strong>RegularChains</strong> package used by <strong>Isolate(f,method=RC)</strong> correctly finds the root.</p>
<p> All-in-all, I am not sure what to make of this. Is this an issue which has been fixed in more recent incarnations of <strong>fsolve</strong> or <strong>Isolate</strong>? Is this a persistent problem? Is there a theoretical reason why the root is being missed, particularly for <strong>Isolate</strong>?<br /><br />Any help or insight would be greatly appreciated.</p>202376Wed, 17 Sep 2014 02:29:12 ZbifurcationmanbifurcationmanHow to export an array from maple to matlab?
http://www.mapleprimes.com/questions/202321-How-To-Export-An-Array-From-Maple-To-Matlab?ref=Feed:MaplePrimes:Version Maple 16
<p>Hi,</p>
<p>I need to transfer an array of size (M,N) from maple to matlab. But i dont know how to make it. Please help me for this. Thanx in advance.</p>
<p>Regards</p>
<p>Sunit</p><p>Hi,</p>
<p>I need to transfer an array of size (M,N) from maple to matlab. But i dont know how to make it. Please help me for this. Thanx in advance.</p>
<p>Regards</p>
<p>Sunit</p>202321Mon, 08 Sep 2014 10:26:59 Zsunitsunitproblem with solving equation, I couldn't find any answer by solve or fsolve commands in maple
http://www.mapleprimes.com/questions/202298-Problem-With-Solving-Equation-I-Couldnt?ref=Feed:MaplePrimes:Version Maple 16
<p>i := I;</p>
<p>assume(a>0);</p>
<p>assume(b>0);</p>
<p>assume(r>0);</p>
<p>assume(k>0);</p>
<p>assume(w>0);</p>
<p>Hz := k*(z^2-2*r*a+r^2)/((z-1)*(z^2-2*b*z+1));</p>
<p>Hzw := eval(Hz, z = exp(i*w)); assume(a > 0);</p>
<p>Habs := simplify(abs(Hzw)^2);</p>
<p>p1 := eval(Habs, w = Pi) = (10^((-3.3018)*(1/20)))^2;</p>
<p>p2 := eval(Habs, w = (1/2)*Pi) = (10^((-.1758)*(1/20)))^2;</p>
<p>p3 := eval(Habs, w = (1/4)*Pi) = (10^(6.425*(1/20)))^2;</p>
<p>p4 := eval(Habs, w = (1/8)*Pi) = (10^(54.5699*(1/20)))^2;</p>
<p>solve({p1, p2, p3, p4})</p>
<p> </p><p>i := I;</p>
<p>assume(a>0);</p>
<p>assume(b>0);</p>
<p>assume(r>0);</p>
<p>assume(k>0);</p>
<p>assume(w>0);</p>
<p>Hz := k*(z^2-2*r*a+r^2)/((z-1)*(z^2-2*b*z+1));</p>
<p>Hzw := eval(Hz, z = exp(i*w)); assume(a > 0);</p>
<p>Habs := simplify(abs(Hzw)^2);</p>
<p>p1 := eval(Habs, w = Pi) = (10^((-3.3018)*(1/20)))^2;</p>
<p>p2 := eval(Habs, w = (1/2)*Pi) = (10^((-.1758)*(1/20)))^2;</p>
<p>p3 := eval(Habs, w = (1/4)*Pi) = (10^(6.425*(1/20)))^2;</p>
<p>p4 := eval(Habs, w = (1/8)*Pi) = (10^(54.5699*(1/20)))^2;</p>
<p>solve({p1, p2, p3, p4})</p>
<p> </p>202298Thu, 04 Sep 2014 08:14:49 ZmrhrezamrhrezaHow to use PlanePlot (after with(Student[LinearAlgebra]) ) for 2 equations?..
http://www.mapleprimes.com/questions/202252-How-To-Use-PlanePlot-after-WithStudentLinearAlgebra?ref=Feed:MaplePrimes:Version Maple 16
<p>Dear Maple experts,</p>
<p> </p>
<p>I would like to visualize the equation -3*x+2*y+3*z=0 and (with other color) 2*y+3*z =0. I used the following commands:</p>
<p>with(Student[LinearAlgebra]):<br>infolevel[Student[LinearAlgebra]]:=1:<br>PlanePlot(-3*x+ 2*y + 3*z = 0, [x,y,z], normaloptions=[shape=harpoon], showbasis);</p>
<p>But I do not know how to show at the same time the second equation (2*y+3*z=0 ).</p>
<p> </p>
<p>How should I proceed? Any hint?</p>
<p>Thanks for your attention,</p>
<p> </p>
<p>Jean-Jaques</p>
<p> </p><p>Dear Maple experts,</p>
<p> </p>
<p>I would like to visualize the equation -3*x+2*y+3*z=0 and (with other color) 2*y+3*z =0. I used the following commands:</p>
<p>with(Student[LinearAlgebra]):<br />infolevel[Student[LinearAlgebra]]:=1:<br />PlanePlot(-3*x+ 2*y + 3*z = 0, [x,y,z], normaloptions=[shape=harpoon], showbasis);</p>
<p>But I do not know how to show at the same time the second equation (2*y+3*z=0 ).</p>
<p> </p>
<p>How should I proceed? Any hint?</p>
<p>Thanks for your attention,</p>
<p> </p>
<p>Jean-Jaques</p>
<p> </p>202252Mon, 25 Aug 2014 21:40:38 ZjeanjacquesvvidejeanjacquesvvideFind extremes of numeric solution of ODE system
http://www.mapleprimes.com/questions/202181-Find-Extremes-Of-Numeric-Solution-Of-ODE-System?ref=Feed:MaplePrimes:Version Maple 16
<p>Hello! How can I find extremes of numeric solution of ODE system obtained using "dsolve"? Can I use something like "extrema" function?</p><p>Hello! How can I find extremes of numeric solution of ODE system obtained using "dsolve"? Can I use something like "extrema" function?</p>202181Sun, 17 Aug 2014 11:16:04 Zdmytro_rubanovdmytro_rubanovFinding a term into an expression
http://www.mapleprimes.com/questions/202147-Finding-A-Term-Into-An-Expression?ref=Feed:MaplePrimes:Version Maple 16
<p>Dear friends:</p>
<p>I have a long expression having a/some RootOf(something..) inside it. </p>
<p>Any way to get just that "something..", i.e., the argument of RootOf() from that expression?</p>
<p> </p>
<p>Thank you very much.</p>
<p>César Lozada</p>
<p> </p>
<p> </p><p>Dear friends:</p>
<p>I have a long expression having a/some RootOf(something..) inside it. </p>
<p>Any way to get just that "something..", i.e., the argument of RootOf() from that expression?</p>
<p> </p>
<p>Thank you very much.</p>
<p>César Lozada</p>
<p> </p>
<p> </p>202147Tue, 12 Aug 2014 12:08:28 Zcloz54cloz54Nonlinear system of 14 equations/unknowns, 9 parameters: eliminate
http://www.mapleprimes.com/questions/201996-Nonlinear-System-Of-14-Equationsunknowns?ref=Feed:MaplePrimes:Version Maple 16
<p>Hello,</p>
<p>this is the second time I'm writing.</p>
<p>I posted this question in June http://www.mapleprimes.com/questions/201781-System-Of-Parametric-Equations.</p>
<p>This time I have a similar problem because I'm trying to find a solution for a parametric system of equations but the number of equations and parameters is much bigger and using the tips you gave me last time I couldn't reach any result.</p>
<p>Here is the system:</p>
<p>1) alpha[1]=v*a*u*b ;<br>2) alpha[2]=v*a*u*(1-b);<br>3) alpha[3]= v*z*c*(1-a) ;<br>4) alpha[4]=v*z*(1-a)*(1-c) ;<br>5) alpha[11]=1/2*v*a* u* b* (-p*u*b+p*u*b*a+b*g-g);<br>6) alpha[22]=1/2*v*a*u*(1-b)* (p u b-p u b a-b g-p u+p u a);<br>7) alpha[33] =1/2*v*c*z*(1-a)* (c* (-z*p*a+q)-q);<br>8) alpha[44]=1/2*v*z*((1-a)*(1-c)* (c*z*p*a-z*p*a-q*c);<br>9) alpha[12]=v*a*u*b*(1- b)*(-p*u+p*u*a+g) ;<br>10) alpha[13]=v*a*u*b*z*c*p*(1-a) ;<br>11) alpha[14]=a*u*b*z*(1-a)*(1-c) ;<br>12) alpha[23]=a*u*z*c*(1-a)*(1-b);<br>13) alpha[24]=v*a*u*z*p*(1-a)*(1-b)*(1-c);<br>14) alpha[34]= v*c*z*(1-a)*(1-c)*(-z*p*a+q);</p>
<p> </p>
<p>I have 14 equations/unknowns and 8 parameters (a, b, c, u, v, z, p, q).</p>
<p>I would like to write this system only in terms of alphas. In order to do so, I usually try to find the value for the parameters and the substitute them into the equations (and I have already found b,c,g,q using this technique) but I couldn't manage to find all of them. </p>
<p>Howveer, as you suggested me, with Maple there is the command "eliminate" that implement exactly what I'm looking for but I can't make it work.</p>
<p>This is my code:</p>
<p>> sys := {alpha[1] = v*a*u*(1-b), alpha[2] = v*a*u*b, alpha[3] = v*z*c*(1-a), alpha[4] = v*z*(1-a)*(1-c), alpha[11] = (1/2)*v*a*u*(1-b)*(p*u*b-p*u*b*a-b*g-p*u+p*u*a), alpha[12] = v*a*u*b*(1-b)*(-p*u+p*u*a+g), alpha[13] = z*c*a*u*(1-a)*(1-b), alpha[14] = v*z*a*u*p*(1-a)*(1-b)*(1-c), alpha[22] = (1/2)*v*a*u*b*(-p*u*b+p*u*b*a+b*g-g), alpha[23] = v*z*c*a*u*b*p*(1-a), alpha[24] = z*a*u*b*(1-a)*(1-c), alpha[33] = (1/2)*v*c*z*(1-a)*(c*(-z*p*a+q)-q), alpha[34] = v*c*z*(1-a)*(1-c)*(-z*p*a+q), alpha[44] = (1/2)*v*z*(1-a)*(1-c)*(c*z*p*a-z*p*a-q*c)};</p>
<p>> eliminate(sys, {a,b,c, p, q, u, v, z});</p>
<p>> simplify(%, size);</p>
<p> </p>
<p>I also tries to substitute in the system the four parameters I already found but still I can't find a solution.</p>
<p>What am I doing wrong? Or the problem is that it is too complicated?</p>
<p> </p>
<p>Thank you for your attention,</p>
<p>Elena</p><p>Hello,</p>
<p>this is the second time I'm writing.</p>
<p>I posted this question in June http://www.mapleprimes.com/questions/201781-System-Of-Parametric-Equations.</p>
<p>This time I have a similar problem because I'm trying to find a solution for a parametric system of equations but the number of equations and parameters is much bigger and using the tips you gave me last time I couldn't reach any result.</p>
<p>Here is the system:</p>
<p>1) alpha[1]=v*a*u*b ;<br />2) alpha[2]=v*a*u*(1-b);<br />3) alpha[3]= v*z*c*(1-a) ;<br />4) alpha[4]=v*z*(1-a)*(1-c) ;<br />5) alpha[11]=1/2*v*a* u* b* (-p*u*b+p*u*b*a+b*g-g);<br />6) alpha[22]=1/2*v*a*u*(1-b)* (p u b-p u b a-b g-p u+p u a);<br />7) alpha[33] =1/2*v*c*z*(1-a)* (c* (-z*p*a+q)-q);<br />8) alpha[44]=1/2*v*z*((1-a)*(1-c)* (c*z*p*a-z*p*a-q*c);<br />9) alpha[12]=v*a*u*b*(1- b)*(-p*u+p*u*a+g) ;<br />10) alpha[13]=v*a*u*b*z*c*p*(1-a) ;<br />11) alpha[14]=a*u*b*z*(1-a)*(1-c) ;<br />12) alpha[23]=a*u*z*c*(1-a)*(1-b);<br />13) alpha[24]=v*a*u*z*p*(1-a)*(1-b)*(1-c);<br />14) alpha[34]= v*c*z*(1-a)*(1-c)*(-z*p*a+q);</p>
<p> </p>
<p>I have 14 equations/unknowns and 8 parameters (a, b, c, u, v, z, p, q).</p>
<p>I would like to write this system only in terms of alphas. In order to do so, I usually try to find the value for the parameters and the substitute them into the equations (and I have already found b,c,g,q using this technique) but I couldn't manage to find all of them. </p>
<p>Howveer, as you suggested me, with Maple there is the command "eliminate" that implement exactly what I'm looking for but I can't make it work.</p>
<p>This is my code:</p>
<p>> sys := {alpha[1] = v*a*u*(1-b), alpha[2] = v*a*u*b, alpha[3] = v*z*c*(1-a), alpha[4] = v*z*(1-a)*(1-c), alpha[11] = (1/2)*v*a*u*(1-b)*(p*u*b-p*u*b*a-b*g-p*u+p*u*a), alpha[12] = v*a*u*b*(1-b)*(-p*u+p*u*a+g), alpha[13] = z*c*a*u*(1-a)*(1-b), alpha[14] = v*z*a*u*p*(1-a)*(1-b)*(1-c), alpha[22] = (1/2)*v*a*u*b*(-p*u*b+p*u*b*a+b*g-g), alpha[23] = v*z*c*a*u*b*p*(1-a), alpha[24] = z*a*u*b*(1-a)*(1-c), alpha[33] = (1/2)*v*c*z*(1-a)*(c*(-z*p*a+q)-q), alpha[34] = v*c*z*(1-a)*(1-c)*(-z*p*a+q), alpha[44] = (1/2)*v*z*(1-a)*(1-c)*(c*z*p*a-z*p*a-q*c)};</p>
<p>> eliminate(sys, {a,b,c, p, q, u, v, z});</p>
<p>> simplify(%, size);</p>
<p> </p>
<p>I also tries to substitute in the system the four parameters I already found but still I can't find a solution.</p>
<p>What am I doing wrong? Or the problem is that it is too complicated?</p>
<p> </p>
<p>Thank you for your attention,</p>
<p>Elena</p>201996Thu, 17 Jul 2014 10:59:06 Zele88ele88Error, (in convert/matrix) expecting array, rtable or list
http://www.mapleprimes.com/questions/201976-Error-in-Convertmatrix-Expecting?ref=Feed:MaplePrimes:Version Maple 16
<p>hello, I put in the code:</p>
<p>> with(plots), with(ColorTools), with(LinearAlgebra), with(RandomTools), with(ExcelTools);<br>> A := `<|>`(`<,>`(1, 2, 0, 2, 3, 4, 3, 4, 7, 9, 5, 3, 4, 6, 7, 8, 3), `<,>`(0, 4, 7, 2, 2, 2, 4, 5, 6.5, 7, 5, 3, 2, 5, 9, 0, 1), `<,>`(1, 5, 2, 0, 4, 1, 2, 3, 4.3, 7, 8, 5, 3, 2, 9, 6, 4)); J := convert(Import("testB1.xlsx", "Cartesian", "E2:G18"), matrix);<br>Error, (in convert/matrix) expecting array, rtable or list<br>> B := matrix([[1], [.2], [.1], [.8], [.5], [.6], [.8], [.764], [.234], [0.4e-1], [.89], [.36], [.687], [.627], [.689], [.328], [.139]]); H := convert(Import("test.xlsx", "Cartesian", "D2:D18"), matrix);<br>Error, (in convert/matrix) expecting array, rtable or list<br>> C := [seq(Color([H[i, 1], 0, 0]), i = 1 .. RowDimension(A))];</p>
<p> </p>
<p>And i get the error message everytime I try import m data list and I dont understand why. Any help would be appreciated. Thank you</p>
<p> </p>
<p>Jennifer</p><p>hello, I put in the code:</p>
<p>> with(plots), with(ColorTools), with(LinearAlgebra), with(RandomTools), with(ExcelTools);<br />> A := `<|>`(`<,>`(1, 2, 0, 2, 3, 4, 3, 4, 7, 9, 5, 3, 4, 6, 7, 8, 3), `<,>`(0, 4, 7, 2, 2, 2, 4, 5, 6.5, 7, 5, 3, 2, 5, 9, 0, 1), `<,>`(1, 5, 2, 0, 4, 1, 2, 3, 4.3, 7, 8, 5, 3, 2, 9, 6, 4)); J := convert(Import("testB1.xlsx", "Cartesian", "E2:G18"), matrix);<br />Error, (in convert/matrix) expecting array, rtable or list<br />> B := matrix([[1], [.2], [.1], [.8], [.5], [.6], [.8], [.764], [.234], [0.4e-1], [.89], [.36], [.687], [.627], [.689], [.328], [.139]]); H := convert(Import("test.xlsx", "Cartesian", "D2:D18"), matrix);<br />Error, (in convert/matrix) expecting array, rtable or list<br />> C := [seq(Color([H[i, 1], 0, 0]), i = 1 .. RowDimension(A))];</p>
<p> </p>
<p>And i get the error message everytime I try import m data list and I dont understand why. Any help would be appreciated. Thank you</p>
<p> </p>
<p>Jennifer</p>201976Mon, 14 Jul 2014 14:56:10 ZjentoxjentoxModule/Package - Why are some functions (proc) not loading correctly?
http://www.mapleprimes.com/questions/201974-ModulePackage--Why-Are-Some-Functions-proc?ref=Feed:MaplePrimes:Version Maple 16
<p>I've been using a maple package (written by another author) on earlier versions of Maple. Recently I have been trying to rewrite it so it's a bit more Maple 16+ friendly (since I've read that Maple is not forward-compatible). However, I have been experiencing similar <em>strange</em> behavior in both the original and my current version: </p>
<p>After saving the module to my personal library, I load with(MyPackage). Most functions work fine (all but a handful out of dozens). However, some functions won't be recognized (e.g., Coproduct(...) will return itself Coproduct(...)). </p>
<p>HOWEVER, when I execute the code in the module in its own Maple worksheet, <em>all</em> functions are recognized and work perfectly. I look at the difference in the code between the functions that work upon loading the package (using with(MyPackage) command in a separate sheet) and those that don't, and there is no difference.</p>
<p>I'm assuming I'll just have to cut and paste the hundreds of lines of code for my package into each sheet I'd like to use it in, since I haven't been able to find others experience this problem in the knowledge base. I'm hoping someone will be able to help out, however.</p><p>I've been using a maple package (written by another author) on earlier versions of Maple. Recently I have been trying to rewrite it so it's a bit more Maple 16+ friendly (since I've read that Maple is not forward-compatible). However, I have been experiencing similar <em>strange</em> behavior in both the original and my current version: </p>
<p>After saving the module to my personal library, I load with(MyPackage). Most functions work fine (all but a handful out of dozens). However, some functions won't be recognized (e.g., Coproduct(...) will return itself Coproduct(...)). </p>
<p>HOWEVER, when I execute the code in the module in its own Maple worksheet, <em>all</em> functions are recognized and work perfectly. I look at the difference in the code between the functions that work upon loading the package (using with(MyPackage) command in a separate sheet) and those that don't, and there is no difference.</p>
<p>I'm assuming I'll just have to cut and paste the hundreds of lines of code for my package into each sheet I'd like to use it in, since I haven't been able to find others experience this problem in the knowledge base. I'm hoping someone will be able to help out, however.</p>201974Sun, 13 Jul 2014 18:30:04 ZoughteroughterMaple having trouble simplifying
http://www.mapleprimes.com/questions/201840-Maple-Having-Trouble-Simplifying?ref=Feed:MaplePrimes:Version Maple 16
<p>Well, I'm having issues getting this expression to simplify. I have a bunch of polynomial results I store in an array, and the simplify command isn't cancelling obvious terms which should cancel out.<br><br><a href="/view.aspx?sf=201840_question/June_18.mw">June_18.mw</a><br><br>Curiously, it will simplify if I use the command by selecting it from the drop down menu when I select the expression (see lines (7) vs. (8))</p><p>Well, I'm having issues getting this expression to simplify. I have a bunch of polynomial results I store in an array, and the simplify command isn't cancelling obvious terms which should cancel out.<br><br><a href="/view.aspx?sf=201840_question/June_18.mw">June_18.mw</a><br><br>Curiously, it will simplify if I use the command by selecting it from the drop down menu when I select the expression (see lines (7) vs. (8))</p>201840Tue, 24 Jun 2014 01:17:55 Zber9erudber9erudwriting data during iteration
http://www.mapleprimes.com/questions/201807-Writing-Data-During-Iteration?ref=Feed:MaplePrimes:Version Maple 16
<p>I am writing a big numerical code in maple. I need to write the results in each step in a file. I mean in the first step of loop it writes the results in the first line of a text file, in the second step writes in the second line and to the end. when I use writedata command, it needs to write a complete array or matrix and it is not what i need. In other words I want to save data for each steps of iteration during the calculation and when it goes to ther next step it writes the result in the next line.</p>
<p>Can you help me to perform it?</p>
<p>Thanks</p><p>I am writing a big numerical code in maple. I need to write the results in each step in a file. I mean in the first step of loop it writes the results in the first line of a text file, in the second step writes in the second line and to the end. when I use writedata command, it needs to write a complete array or matrix and it is not what i need. In other words I want to save data for each steps of iteration during the calculation and when it goes to ther next step it writes the result in the next line.</p>
<p>Can you help me to perform it?</p>
<p>Thanks</p>201807Tue, 17 Jun 2014 15:46:16 ZpuyapuyaHow to create all possible lists containing m elements from an n element list?
http://www.mapleprimes.com/questions/201773-How-To-Create-All-Possible-Lists-Containing?ref=Feed:MaplePrimes:Version Maple 16
<p>Hey everyone,<br><br>New here but I'm a bit stuck. Ive looked around in list tools as well as tried but I havent had any luck.<br><br>Suppose I have a list defined as FirstList:=[A,B,C,D,E,F]. Now I want to create (and label) all possible<br>lists from FirstList which contain 4 elements which dont have an element repeated within the same list<br>In this example, there are 15 lists in total i.e.<br><br>Sublist[1]:=[A,B,C,D]:<br>Sublist[2]:=[A,B,C,E]:<br>Sublist[3]:=[A,B,C,F]:<br>Sublist[4]:=[A,C,D,E]:<br><br>..etc<br><br>Is there a simple way to do this???<br><br>Any help is appreciated!<br><br></p><p>Hey everyone,<br><br>New here but I'm a bit stuck. Ive looked around in list tools as well as tried but I havent had any luck.<br><br>Suppose I have a list defined as FirstList:=[A,B,C,D,E,F]. Now I want to create (and label) all possible<br>lists from FirstList which contain 4 elements which dont have an element repeated within the same list<br>In this example, there are 15 lists in total i.e.<br><br>Sublist[1]:=[A,B,C,D]:<br>Sublist[2]:=[A,B,C,E]:<br>Sublist[3]:=[A,B,C,F]:<br>Sublist[4]:=[A,C,D,E]:<br><br>..etc<br><br>Is there a simple way to do this???<br><br>Any help is appreciated!<br><br></p>201773Wed, 11 Jun 2014 22:30:13 ZNeedMapleListHelpNeedMapleListHelpExecuting Sections in Maple
http://www.mapleprimes.com/questions/201763-Executing-Sections-In-Maple?ref=Feed:MaplePrimes:Version Maple 16
<p>Is there away to quickly execute a specific section within Maple? I know that I can execute a selection, but that sometimes requires me to select several lines of Maple code and can be tedious and tiresome.</p><p>Is there away to quickly execute a specific section within Maple? I know that I can execute a selection, but that sometimes requires me to select several lines of Maple code and can be tedious and tiresome.</p>201763Mon, 09 Jun 2014 20:09:28 ZBoundary condition - Partial differential equation
http://www.mapleprimes.com/questions/201754-Boundary-Condition--Partial-Differential?ref=Feed:MaplePrimes:Version Maple 16
<p>Hello everybody,</p>
<p>I am trying to solve a partial differential equation (wave equation) with initial conditions that contain derivative and x-varying values</p>
<p>My equation <br>Uxx – Utt = 0 (hiperbólica) where xx and tt denote second partial derivatives with respect to x and t<br>0 <= x <= 10; t > 0; <br>u(0,t) = u(10,t) = 0; <br>Ut(x,0) = 0;<br>u(x,0)= <br>x for 0 <= x < 5<br>10-x for 5 <= x <= 10</p>
<p>I ve defined my equation as follow<br>> PDE := diff(u(x,t),x,x)=diff(u(x,t),t,t);<br><img src="webkit-fake-url://8BDFBF0A-1CD1-4845-BE40-0906E4CA77C8/image.tiff" alt=""></p>
<p>I m first trying without the x-varying initial condition.</p>
<p>> IBC := {u(0,t)=0,u(10,t)=0,u(x,0)=10-x,diff(u(x,0), t) = 0};<br>Returns the ugly<br><img src="webkit-fake-url://FE9626D1-563F-48FD-9C3C-5A53F517B3FB/image.tiff" alt=""><br>And that gives error when trying to solve<br>> pds := pdsolve(PDE,IBC,numeric);<br>Error, (in pdsolve/numeric/process_IBCs) initial/boundary condition does not contain the dependent variables of the PDE: 0 = 0</p>
<p>Another try with <br>> IBC := {u(0,t)=0,u(10,t)=0,u(x,0)=10-x,diff(u(x,t=0), t) = 0};<br><img src="webkit-fake-url://262C213B-B19A-42E4-8769-8CD2C30BFF3C/image.tiff" alt=""><br>Looks like more promissing but returns (in a solving attempt)<br>> pds := pdsolve(PDE,IBC,numeric);<br>Error, (in pdsolve/numeric/process_IBCs) initial/boundary condition does not contain the dependent variables of the PDE: 0 = 0</p>
<p><br>Regarding the x varying initial condition, I ve tried the `assuming` keyword in various attempts but without success.</p>
<p>Anybody could help on the matter?</p>
<p><br>Thanks in advance for anytip. <br>Have a good day<br>Nicolas</p><p>Hello everybody,</p>
<p>I am trying to solve a partial differential equation (wave equation) with initial conditions that contain derivative and x-varying values</p>
<p>My equation <br />Uxx – Utt = 0 (hiperbólica) where xx and tt denote second partial derivatives with respect to x and t<br />0 <= x <= 10; t > 0; <br />u(0,t) = u(10,t) = 0; <br />Ut(x,0) = 0;<br />u(x,0)= <br />x for 0 <= x < 5<br />10-x for 5 <= x <= 10</p>
<p>I ve defined my equation as follow<br />> PDE := diff(u(x,t),x,x)=diff(u(x,t),t,t);<br /><img src="webkit-fake-url://8BDFBF0A-1CD1-4845-BE40-0906E4CA77C8/image.tiff" alt="" /></p>
<p>I m first trying without the x-varying initial condition.</p>
<p>> IBC := {u(0,t)=0,u(10,t)=0,u(x,0)=10-x,diff(u(x,0), t) = 0};<br />Returns the ugly<br /><img src="webkit-fake-url://FE9626D1-563F-48FD-9C3C-5A53F517B3FB/image.tiff" alt="" /><br />And that gives error when trying to solve<br />> pds := pdsolve(PDE,IBC,numeric);<br />Error, (in pdsolve/numeric/process_IBCs) initial/boundary condition does not contain the dependent variables of the PDE: 0 = 0</p>
<p>Another try with <br />> IBC := {u(0,t)=0,u(10,t)=0,u(x,0)=10-x,diff(u(x,t=0), t) = 0};<br /><img src="webkit-fake-url://262C213B-B19A-42E4-8769-8CD2C30BFF3C/image.tiff" alt="" /><br />Looks like more promissing but returns (in a solving attempt)<br />> pds := pdsolve(PDE,IBC,numeric);<br />Error, (in pdsolve/numeric/process_IBCs) initial/boundary condition does not contain the dependent variables of the PDE: 0 = 0</p>
<p><br />Regarding the x varying initial condition, I ve tried the `assuming` keyword in various attempts but without success.</p>
<p>Anybody could help on the matter?</p>
<p><br />Thanks in advance for anytip. <br />Have a good day<br />Nicolas</p>201754Sun, 08 Jun 2014 14:40:17 ZMikoulasseMikoulasseBuild array of coordinates from implicit equation.
http://www.mapleprimes.com/questions/201747-Build-Array-Of-Coordinates-From-Implicit?ref=Feed:MaplePrimes:Version Maple 16
<p>Hallo,</p>
<p>Is there a fairly straightforward method for obtaining an array of coordinates from an implicit equation? I have an ellipse defined implicitly (by a horrendously involved expression) and can't figure out how to extract a set of coordinates from an implicitplot. I'm reluctant to use seq and fsolve with a fixed stepsize.</p>
<p>Would be grateful for some insight!</p>
<p>Thanks.</p>
<p>Weirp</p><p>Hallo,</p>
<p>Is there a fairly straightforward method for obtaining an array of coordinates from an implicit equation? I have an ellipse defined implicitly (by a horrendously involved expression) and can't figure out how to extract a set of coordinates from an implicitplot. I'm reluctant to use seq and fsolve with a fixed stepsize.</p>
<p>Would be grateful for some insight!</p>
<p>Thanks.</p>
<p>Weirp</p>201747Fri, 06 Jun 2014 22:08:16 Zweirpweirp