All Questions

22 views

$H_{\infty}$ optimization of transfer function matrix [duplicate]

I have a two-dimensional $(2 \times 2)$ transfer function matrix like this: $$G(s) = \begin{pmatrix} \frac{1}{xs+1} & \frac{1}{s+0.5}\\ \frac{3}{s+3}& \frac{1}{ys+2} \end{pmatrix}$$ The ...
77 views

Collecting terms in an expression [duplicate]

I have an expression: ...
90 views

Cropping a Plot without rasterization

Suppose that I make a plot of $x^2$ vs. $x$: myPlot = Plot[x^2, {x, -1, 1}, Frame -> True] If I click on the plot, I see the orange handles with which I can ...
48 views

SSH known hosts in Windows (Error code = 124)

I had to re-install Raspbian OS and now it has new SSH key. SSH clients usually let ignore this fact and save the new key, but not now. Mathematica gives no way to go if the Host Key was changed. I ...
99 views

Sporadic bugs in multidimensional SparseArray objects

Resolution WRI affirms that SparseArray[__] is broken (in 9.0 and 9.01) WRI's suggested workaround is SparseArray//Normal My ...
362 views

Most influential and/or disrupting features introduced with new versions of Mathematica

This is something that has been bugging me for ages. With every upgrade, Mathematica has added new functionalities and amendend some of its bugs. In the process, though, some older functionality has ...
112 views

Saving a graph of a great number of nodes

I'm developing a code where I get graphs with over 10K nodes. These graphs have a particular relationship between clustering and degree that I need to save for future analysis. The problem is when I ...
141 views

Euler's method for system of differential equation

I need to program Euler's method to solve a system of two diffferential equations of first order. Fist, I have programmed the Euler's method for just one differential equation: ...
100 views

I was trying to run some notebook I downloaded from MathWorld, but lots of them need << MathWorldCurves I tried to google it , only to find this, but ...
175 views

The introduction for Context in Wagner's book is out of date? [duplicate]

In Section 8.1.1 (P230 of the book, P249 of the PDF) of Wagner's book, the following example is shown: x = 5; tempx = 6; Begin["temp"]; {x, Global`x} The ...
68 views

Fitting data using a series of Sin and Cos

I have the following data representing the normal displacement caused by a normal load applied at the middle cross section of a cylinder: I've made the data available here. I am trying to fit ...
57 views

For loops overwriting dynamically named lists [closed]

For some reason the following code is overwriting previous loops with the present one, and I really don't see why it is doing it. I included the output to show. Any clues? ...
76 views

How do I NOT change the input/output number when editing?

I tried to search for a topic on this, but didn't seem to find anything, so here goes. I'm pretty new to Mathematica, so there are a lot of things I don't know yet, but one thing is pretty annoying ...
92 views

Improving performance in the generation of random (directed acyclic) graphs

I need to generate large (directed, acyclic, transitive) graphs. My code in Mathematica gets very slow for large numbers of vertices. I've tried a number of approaches and I can't find any significant ...
54 views

The output is the same as Input when I add the boundary conditions to a PDE

I am trying to solve a PDE in the first order with specific boundary conditions. When I solve use DSolve without the boundary conditions, Mathematica gives me an answer in an arbitrary function. When ...
71 views

How to combine multiple functions into a single function, indexed bya new argument

I have a system of expressions (matrices) which correspond to increasing orders of precision in a theory. These expressions are quite complex (require about 40+ lines of code to produce) and are not ...
65 views

Summing Over a Variable Number of Indices

I am trying to figure out the best way to include a variable number of indexes of summation in a program. For example: Suppose I want to define a function $g[n,s]$ that returns the sum ...
67 views

Arguments for ChartElementFunction

I was reading the documentation for BubbleChart and I saw this example ...
28 views

Drawing Target Layers on the Top of 3D Heart for the Women's Day?

For the sake of Women's Day, I would like to draw target sign on the heart and write there something like "Best Mother" or just ...
28 views

i do not understand why NSolve::ivar error is occouring? [duplicate]

PLEASE HELP v[t] = Sqrt[(x'[t])^2 + (y'[t])^2 + (z'[t])^2] NSolve[{z''[t] == -9.8 - 0.0154 z'[t]*v[t], y''[t] == -0.0154 y'[t] v[t] + 0.0033 x'[t] v[t], x''[t] == v[t] (-0.0154 x'[t] - 0.0033 ...
77 views

Simulation code performance tuning

The following simulation takes over 20 seconds for evaluation. I have difficulty re-coding it with Nest and Map or Compile functions to make it more efficient. Can some one help with this? The ...
90 views

combining manipulate with “static” plot

Is there a way to show a plot of a "static" function as background for a manipulate panel ? In other words: I have put into a manipulate a trajectory (solution of a system of two differential ...
39 views

Slow mixture fitting when having ill-conditioned covariance matrices. How to make it faster?

I'm using Mathematica 9.0 to fit multidimensional observations with a gaussian mixture. To do so I first adapted these steps to ensure that the mixture parameters are well defined (see ...
62 views

Can ParametricNDsolve be used for coupled PDEs with 5 parameters?

I have a system of coupled PDEs with five parameters that I only know ranges for rather than explicit values, and I was wondering if I could define a parametric equation with ParametricNDSolve and ...
112 views

Render dynamic Graphics objects static

As was discussed in the comments of another question (MathLink Graphical Output (Plots) to File), Graphcis objects produced by commands such as ...
80 views

How to format the data in a table to have only numbers

This question is in continuation of my earlier query, how to store output of a function in a table for future use. I am able to store the output of my function in a table, however the table consists ...
881 views

Why does Simplify[b-a] give -a+b and not b-a?

Simplify[b - a] results in -a + b. I prefer b - a, which is a bit simpler (3 symbols instead ...