Hi to everybody I am trying to plot some bode plots, but want to use the LogLinearPlot command (the BodePlot is yet too obscure to me, sorry). My impedance matrices are rather complex in the sense that they are based on 7x7 matrices and that it uses complex numbers. Once I get the impedance expressions and its corresponding admittance I define some (transfer) functions. But it takes age to plot them. And to plot the ARG of the function is even worse. I have added dots after all the numbers to force the use of floating point numbers and I have the feeling that Mathematica makes too many recursions to plot the functions. I have added a limit to PlotPoints and MaxRecursion, but without too much success. I have also tried to find the roots of the admittance function using NDSolve, but this take seven longer (not shown in the attached notebook). I cannot believe that this is the normal speed of Mathematica, I am sure that I am doing something wrong. I am new and will be probably doing a lot of mistakes. Can somebody give me some useful hints? Thank you very much. Stefan P.D. I have attached the notebook. Attachments:

Hi to everybody I finally found a solution to make plots much faster. First I try to use all four cores of my computer (Parallelize) and I try to not increase the numb rod points above a reasonable number (could there be a bug in the LogPlot commands of Mathematica?). I found out that Mathematica tries to count with step one when constructing a table although I wanted later on to represent it on a Log scale (this makes sense to me, as Mathematica does not know what I am going to do with the table). But this was very, very slow. Could this be bug in the LogPlot functions and that's why it is solo slow? Any how, here is my proposal which fastens the BodePlot representation really a lot. ListLogLinearPlot[ Parallelize[ Table[{10^i,Part[20 Log10[Abs[function[2. PiN I 10^i]]], 1]}, {i, 2, 5,0.01}]], PlotLegends -> {"function"}, Joined -> True, GridLines -> Automatic, GridLinesStyle -> Directive[GrayLevel[0.8]], Frame -> True] ListLogLinearPlot[ Parallelize[ Table[{10^i, Part[DegN Arg[function[2. PiN I 10^i]], 1]}, {i, 2, 5, 0.01}]], PlotLegends -> {"function"}, PlotRange -> {Automatic, {-180, 180}}, Joined -> True, GridLines -> Automatic, GridLinesStyle -> Directive[GrayLevel[0.8]], Frame -> True] The number of points can be increased with the step when constructing the table (here 0.01) One ListPlot is for the magnitude and the other for the phase (the phase was even worse to plot with the normal LogLinearPlot. Good luck and thank you to all for your help. Stefan

This requires some elaborated work. The basic idea is to make all function "algebraically-ready" before they are inserted into the plot function. Here is an example: f[x] = Det[Inverse[{{1,2},{3,x}}]] g[x] := Det[Inverse[{{1,2},{3,x}}]] Plot[f[x],{x,100,200}] Plot[g[x],{x,100,200}] The first plot should be significantly faster than the second because `f` has the `rhs` evaluated already during definition while the `g` looks for the inversion first and compute the determination. Check the downvalues of `f` and `g` respectively: Use this idea to precompute functions. For example, `Yiidealtotal` is thus converted to a rational function before it is inserted into the plot funciton: Some notes about the optimization: Numeric computation may yield imaginary residues in coefficients, which are difficult for simplification. You want to take a look `Simplify[Chop[#]]&` function to knock down the complicated expressions. To simplify a list of function, you can choose the parallel function to accelerate. For `Yi[x]`: Yi[s_] = ParallelMap[Simplify[Chop[#]] &, nciM.Inverse[ZLRC[s]].nci]; Use the attached notebook to take a look at the details. PS I use high precision numbers throughout the notebook to handle the large coefficients. Attachments:

Thank your very much Shenghui! I had the feeling that it has something to do with precomputing the function earlier instead of inverting at each point the plot takes place. I have a lot to learn! I will go through your improved file and your examples immediately. Thank you again for your help. Stefan

LogLinearPlot for Bode too slow