MaplePrimes - Questions and Posts tagged with model
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en-us2016 Maplesoft, A Division of Waterloo Maple Inc.Maplesoft Document SystemSat, 23 Jul 2016 21:11:19 GMTSat, 23 Jul 2016 21:11:19 GMTThe most recent questions and posts on MaplePrimes tagged with modelhttp://www.mapleprimes.com/images/mapleprimeswhite.jpgMaplePrimes - Questions and Posts tagged with model
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Seasonal fluctuation of model
http://www.mapleprimes.com/questions/209968-Seasonal-Fluctuation-Of--Model?ref=Feed:MaplePrimes:Tagged With model
<p>Howdy,</p>
<p>I am trying to create a mathmatical model that shows a predator-prey relationship along with seasonal variations (hibernation). I made two piecewise functions where one is "on" during the winter and the other is "off" during the winter and the model worked well for one unit of time. </p>
<p>My problem is that I would like the piecewise functions to apply over an arbitrary amount <span style="text-decoration: line-through;">of time units</span> periods without having to set the range within the function itself for 100 units of time. I was thinking that a for loop would work but i'm not sure how I would impliment that.</p>
<p>Thanks in advance!!</p>
<p>Edit: </p>
<p>Here's a little bit more info on the problem.</p>
<p>I have three O.D.E's in an array..</p>
<p>ode := {r'(t),h'(t),c'(t)}</p>
<p>which are dependent on a list of parameters..</p>
<p>constants := {a,b,...,s,w,c0,h0,r0};</p>
<p>where s and w are my piecewise functions.</p>
<p>I am able to solve the three odes using dsolve for one period of s and w.</p>
<p>Again, I'm really not sure where to start to make my model periodic.</p><p>Howdy,</p>
<p>I am trying to create a mathmatical model that shows a predator-prey relationship along with seasonal variations (hibernation). I made two piecewise functions where one is "on" during the winter and the other is "off" during the winter and the model worked well for one unit of time. </p>
<p>My problem is that I would like the piecewise functions to apply over an arbitrary amount <span style="text-decoration: line-through;">of time units</span> periods without having to set the range within the function itself for 100 units of time. I was thinking that a for loop would work but i'm not sure how I would impliment that.</p>
<p>Thanks in advance!!</p>
<p>Edit: </p>
<p>Here's a little bit more info on the problem.</p>
<p>I have three O.D.E's in an array..</p>
<p>ode := {r'(t),h'(t),c'(t)}</p>
<p>which are dependent on a list of parameters..</p>
<p>constants := {a,b,...,s,w,c0,h0,r0};</p>
<p>where s and w are my piecewise functions.</p>
<p>I am able to solve the three odes using dsolve for one period of s and w.</p>
<p>Again, I'm really not sure where to start to make my model periodic.</p>209968Thu, 03 Mar 2016 01:12:26 Znrebman1nrebman1Improved Wave Length to Color
http://www.mapleprimes.com/posts/202039-Improved-Wave-Length-To-Color-?ref=Feed:MaplePrimes:Tagged With model
<p>The CIELAB perceptual model of human vision can be used to predict the color of a wavelength in sRGB. I found the CIEDE2000 corrections to hue, chroma, and lighness were required to get the right values in the blue to violet region. The CIEDE2000 results seem pretty close to what I see looking through a diffraction grating considering I have no way of knowing how my eyes are adapted.</p>
<p><strong>Use the new, faster version. It can run in under 1 minute;</strong></p>
<p><strong><a href="/view.aspx?sf=202039_post/nprocWavelength_Color_CIEDE2000.mw">nprocWavelength_Color_CIEDE2000.mw</a> and <a href="/view.aspx?sf=202039_post/WtoC_data.xlsx">WtoC_data.xlsx</a></strong><a href="/view.aspx?sf=202039_post/Wavelength_Color_CIEDE2000.mw"><br></a></p>
<p><strong>You will need the data for the color matching functions in the WtoC Excel File. The data directory can now be controlled in the mw file.</strong></p>
<p><img src="/view.aspx?sf=202039_post/WaveColors.jpg" alt="" width="523" height="349"></p>
<p> </p><p>The CIELAB perceptual model of human vision can be used to predict the color of a wavelength in sRGB. I found the CIEDE2000 corrections to hue, chroma, and lighness were required to get the right values in the blue to violet region. The CIEDE2000 results seem pretty close to what I see looking through a diffraction grating considering I have no way of knowing how my eyes are adapted.</p>
<p><strong>Use the new, faster version. It can run in under 1 minute;</strong></p>
<p><strong><a href="/view.aspx?sf=202039_post/nprocWavelength_Color_CIEDE2000.mw">nprocWavelength_Color_CIEDE2000.mw</a> and <a href="/view.aspx?sf=202039_post/WtoC_data.xlsx">WtoC_data.xlsx</a></strong><a href="/view.aspx?sf=202039_post/Wavelength_Color_CIEDE2000.mw"><br></a></p>
<p><strong>You will need the data for the color matching functions in the WtoC Excel File. The data directory can now be controlled in the mw file.</strong></p>
<p><img src="/view.aspx?sf=202039_post/WaveColors.jpg" alt="" width="523" height="349"></p>
<p> </p>202039Thu, 10 Dec 2015 18:10:17 ZJohn DoleseJohn DoleseNonlinear regression (2)
http://www.mapleprimes.com/questions/204468-Nonlinear-Regression-2?ref=Feed:MaplePrimes:Tagged With model
<div style="padding: 10px 0px 10px 0px; overflow: auto;">
<p>Hello everyone,</p>
<p>I have an nx2 matrix of (x,w) , I need to fit a curve of the form of w = a*( ((x/b)-1)/c+1)^c to the data. since there is a (1/c)^c factor inside the model, I couldn't use any of the regression models that I knew. I'd greatly appreciate any comments that could help me to find the optimum values for a, b and c through regression methods.</p>
<p>Thanks a lot,</p>
<p>Haley</p>
</div>204468Fri, 12 Jun 2015 19:16:18 ZHaley_VSRCHaley_VSRCPicking the right model by min
http://www.mapleprimes.com/questions/204394-Picking-The-Right-Model-By-Min?ref=Feed:MaplePrimes:Tagged With model
<p>loock i have 3 models and a Matrix<br>>m3:=importmatrix("loslobos.txt");<br>>model[1]:=a*x;<br>>model[2]:=a^2*x+b;<br>>model[3]:=C-x^2+a;<br><br>so i apply a command named DataFit and it gives me <br>>g:=Datafit(matrix,model[1]);<br><br>and that throws<br> g:=[3,[a:=5],33];<br>so <br> >g[1];<br>3<br> >g[2];<br>5<br> >g[3];<br>33<br>the variable that i care about is g[1] so every 3 models have differents g[1] so i need to pick the smallest g[1] and then use his model.<br>Example:=<br>>g:=Datafit(matrix,model[1]);<br>g:=[3,[a:=5],33];<br>>gg:=Datafit(matrix,model[2]);<br>gg:=[10,[a:=5,b:=10],44];<br>>G:=Datafit(matrix,model[3]);<br>G:=[1.1,[C:=5,a:=2],88];<br><br>then <br><br>>plots:-display(plot(m3, style = point, symbol = diamond, symbolsize = 9), plot(eval("<strong>MODEL THAT SHOULD BE PLOT"</strong>, <strong>THE G[2] OF THE MODEL</strong>), x = 0 .. 27, color = black));<br><br>The right one here would be <br><br>>plots:-display(plot(m3, style = point, symbol = diamond, symbolsize = 9), plot(eval(model[3], G[2]), x = 0 .. 27, color = black));<br><br>so how do i select the model[3] for my plot? i knnow how the eval works so the problem here is to pick the right model please Help i hope that i isn't that Hard thnx<br> </p><p>loock i have 3 models and a Matrix<br>>m3:=importmatrix("loslobos.txt");<br>>model[1]:=a*x;<br>>model[2]:=a^2*x+b;<br>>model[3]:=C-x^2+a;<br><br>so i apply a command named DataFit and it gives me <br>>g:=Datafit(matrix,model[1]);<br><br>and that throws<br> g:=[3,[a:=5],33];<br>so <br> >g[1];<br>3<br> >g[2];<br>5<br> >g[3];<br>33<br>the variable that i care about is g[1] so every 3 models have differents g[1] so i need to pick the smallest g[1] and then use his model.<br>Example:=<br>>g:=Datafit(matrix,model[1]);<br>g:=[3,[a:=5],33];<br>>gg:=Datafit(matrix,model[2]);<br>gg:=[10,[a:=5,b:=10],44];<br>>G:=Datafit(matrix,model[3]);<br>G:=[1.1,[C:=5,a:=2],88];<br><br>then <br><br>>plots:-display(plot(m3, style = point, symbol = diamond, symbolsize = 9), plot(eval("<strong>MODEL THAT SHOULD BE PLOT"</strong>, <strong>THE G[2] OF THE MODEL</strong>), x = 0 .. 27, color = black));<br><br>The right one here would be <br><br>>plots:-display(plot(m3, style = point, symbol = diamond, symbolsize = 9), plot(eval(model[3], G[2]), x = 0 .. 27, color = black));<br><br>so how do i select the model[3] for my plot? i knnow how the eval works so the problem here is to pick the right model please Help i hope that i isn't that Hard thnx<br> </p>204394Wed, 03 Jun 2015 02:35:30 Z8595197185951971How do I solve s systems of pdes in maple
http://www.mapleprimes.com/questions/204321-How-Do-I-Solve-S-Systems-Of-Pdes-In-Maple?ref=Feed:MaplePrimes:Tagged With model
<p>The model of fixed-bed adsorption column</p>
<p><strong>Fluid phase:</strong></p>
<p>PDE:= diff(U(x, tau),tau)+ psi*Theta*diff(U(x, tau),x)-(1/Pe)*psi*Theta*diff(U(x, tau),$(x, 2))=-3*psi*xi*(U(x, tau)-Q/K);</p>
<p> </p>
<p>IBC:={U(x, 0) = 0,U(0, tau) = 1+(1/Pe)*(D[1](U))(0, tau),(D[1](U))(1, tau)=0};</p>
<p><strong>Particle:</strong></p>
<p>PDE:= diff(Q(r, tau), tau) = diff(Q(r, tau), $(r, 2))+(2/r)*diff(Q(r, tau),r);</p>
<p>IBC:={Q(r, 0) = 0,(D[1](Q))(0, tau) = 0,(1/K)*(D[1](Q))(1, tau)=xi*(U-Q(1, tau)/K)};</p>
<p>Pe:=0.01:</p>
<p>psi:=6780:</p>
<p>Theta:=3.0:</p>
<p>xi:=10000:</p>
<p>I will really appreciate your help. Thanks in anticipation.</p><p>The model of fixed-bed adsorption column</p>
<p><strong>Fluid phase:</strong></p>
<p>PDE:= diff(U(x, tau),tau)+ psi*Theta*diff(U(x, tau),x)-(1/Pe)*psi*Theta*diff(U(x, tau),$(x, 2))=-3*psi*xi*(U(x, tau)-Q/K);</p>
<p> </p>
<p>IBC:={U(x, 0) = 0,U(0, tau) = 1+(1/Pe)*(D[1](U))(0, tau),(D[1](U))(1, tau)=0};</p>
<p><strong>Particle:</strong></p>
<p>PDE:= diff(Q(r, tau), tau) = diff(Q(r, tau), $(r, 2))+(2/r)*diff(Q(r, tau),r);</p>
<p>IBC:={Q(r, 0) = 0,(D[1](Q))(0, tau) = 0,(1/K)*(D[1](Q))(1, tau)=xi*(U-Q(1, tau)/K)};</p>
<p>Pe:=0.01:</p>
<p>psi:=6780:</p>
<p>Theta:=3.0:</p>
<p>xi:=10000:</p>
<p>I will really appreciate your help. Thanks in anticipation.</p>204321Wed, 27 May 2015 09:37:14 ZOloyemikeOloyemikeError occurred when I simulate a build-in model
http://www.mapleprimes.com/questions/204119-Error-Occurred-When-I-Simulate-A-Buildin-Model?ref=Feed:MaplePrimes:Tagged With model
<p>The following error occurred when I simulate a build-in model, anyone could help me to solve this problem? Thanks first</p>
<p><img src="http://www.packme.cn/forum.php?mod=attachment&aid=NDM3NXxkOTYwYzVmYnwxNDMwNDc5MjA5fDIzNTZ8MjUxMg%3D%3D" alt=""></p><p>The following error occurred when I simulate a build-in model, anyone could help me to solve this problem? Thanks first</p>
<p><img src="http://www.packme.cn/forum.php?mod=attachment&aid=NDM3NXxkOTYwYzVmYnwxNDMwNDc5MjA5fDIzNTZ8MjUxMg%3D%3D" alt="" /></p>204119Fri, 01 May 2015 11:21:16 Zzhong chenzhong chen