0
votes
0answers
32 views

I have trouble in sorting a matrix in wolfram mathematica [duplicate]

I have an array of five elements, I have to make permutations of 3 elements. I have my code: A = {1, 2, 3, 4, 5}; n = Permutations[A, {3}]; Now I have to sort ...
4
votes
2answers
203 views

Parametrize a circle as a tube?

I have this code: ...
0
votes
0answers
82 views

How to determine why Solve[] failed?

I don't know what to make of Solve[] failing on this: ...
3
votes
0answers
65 views

Export to MX seems to corrupt the in-memory Dataset

I have a function that does a large number of calculations (by calling out to other smaller functions), and then builds a large Dataset object. Then I do two ...
4
votes
3answers
555 views
0
votes
0answers
66 views

Bug (?) in Mathematica in Derivative of function with Abs [duplicate]

I encountered a weird problem with Derivatives in Mathematica, see the following code: ...
5
votes
1answer
404 views

How to program efficient undershoot/overshoot

I would like to solve the following boundary value problem for $y(x)$ for a fixed value of $k$ between $0 < k <1$: $$y'' + \frac{3}{x} y' - y + \frac{3}{2}y^2 - \frac{k}{2}y^3=0 \\ y'(0) = 0,\...
8
votes
1answer
108 views

Setting an image as the background of a GeoGraphics image

It's easy to set the background of a GeoGraphics image to black, e.g., ...
5
votes
3answers
129 views

Encapsulated plot function misbehaves

To insure a collection of plots has identical appearance, the plot command is encapsulated in a function. The results are undesirable. The fiducial plot is ...
3
votes
2answers
266 views

Recursive Euclidean algorithm in Mathematica

Can anyone explain to me how do I use a recursion, if I don't know the limit? For example, I need the remainder $r$ of the Euclidean algorithm for $\gcd(a,b)$ which equals $0$. I figured out that the ...
4
votes
3answers
88 views

Automatically split an expression and use TrigFactor to solve the parts

I want to simplify the following expression: 1/2*(Sqrt[3]*Cos[x]*la - Sin[x]*la - lb + Sqrt[3]*Cos[x+y]*lf - Sin[x+y]*lf) I used ...
1
vote
3answers
86 views

ListPlot the results of FindMaximum [closed]

I want to plot a list of the form whose elements are of the form {value, {x -> value_x, y -> value_y}} The list generated by FindMaximum applied on ...
7
votes
4answers
153 views

How to map Unevaluated over a list

I have a list {a1, a2, ...... , an}, in which all as have been initialized to a number. I want to get: ...
4
votes
2answers
220 views

Improve simulation speed using Compile

I have two square matrices, a hermitian matrix h and an unitary matrix v. I am interested in the following function ...
5
votes
2answers
235 views

Trigonometric simplification

How can I simplify 1/2 (Sqrt[3] Cos[x] - Sin[x]) in order to get Cos[x + Pi/6] on Mathematica? I saw that Wolfram|Alpha lists ...
0
votes
1answer
97 views

Numerical integral speed

I have the following code to calculate a numerical integral for any given a, however it takes a very long time, even with adaptivemontecarlo, which is not accurate enough: ...
2
votes
1answer
53 views

Animating an InterpolationFunction and its integral

I have a list of data that I interpolate (Omega[t]) and animate - it is working fine, but an Integrate over the ...
19
votes
4answers
925 views

A bug in Integrate

Integrate[(1 + 16 Tan[2 x - y]^2)/(1 + 4 Tan[2 x - y]^2), {x, 0, 2 π}] Mathematica (wrong) output is (tested under versions 8 and 10.0, took ~ 1 minute of CPU ...
1
vote
1answer
53 views
2
votes
1answer
121 views

Missing zero in the CoefficientList

The following list has a length only 10 (not 11) CoefficientList[Series[ArcTan[x]/(1-x^2),{x,0,10}],x] {0, 1, 0, 2/3, 0, 13/15, 0, 76/105, 0, 263/315} It should ...
5
votes
1answer
224 views

Wrong Limit in Mathematica 10.0.0

Bug introduced in 9.0.0 and fixed in 10.0.1 Limit[(Log[(3+Sqrt[5])/2]/(2*Log[(1+Sqrt[5])/2]))^(-1-2*n), n -> Infinity] Mathematica (wrong) output: ...
1
vote
2answers
447 views

Plotting a Hill function [closed]

I've Just recently gotten this program and cant plot this function, F(X)=1/(1+(X/K)^n) for X=0 to 4 nmol/m^3, K=1 nmol/m^3, F(X)= 0 to 1, and n=1,2,4,8,16 Now I know how to specify the limits and ...
5
votes
2answers
145 views

Generating and Imaging of the water molecules with Graphics3D [duplicate]

my problem is I don't know how to generate e.g. 20 water molecules: Graphics3D[ Rotate[First@ChemicalData["Water", "MoleculePlot"], 45 Degree, {8, .5, 0}]] ...
11
votes
1answer
220 views

Wrong Limit with LaguerreL

Bug introduced in 7.0 and fixed in 10.2.0 Limit[(n! LaguerreL[n,-1]/(n^(n+1/4)/Sqrt[2]/E^(n-2 Sqrt[n]+1/2))-1) Sqrt[n], n->∞] Mathematica (wrong) output <...
5
votes
3answers
314 views

Generate a list of equations of curves and plot them

I want to plot a series of lines. This is how I did it: ...
-2
votes
1answer
112 views

Interpolate/extrapolate a gate charge curve from two different curves

Gate charge measured data. I have gate-charge measurement plots and Excel data for two operating points for a power MOSFET. Vds = 60 V, Id = 50 A Vds = 600 V, Id = 8 mA Can I generate a plot with ...
1
vote
1answer
72 views

How to disable dynamic update in DynamicModule when certain variable is updated [closed]

I have a UI with DynamicModules. I have a progress bar, whenever the varibale progress updates, the ...
5
votes
1answer
344 views

ODE fitting to dataset

So, I have a ODE system, it is a complex biochemical kinetic mechanism with six species changing over time. ...
3
votes
5answers
195 views

Converting multi variable expression into a function

So I have this rather complicated looking expression ...
2
votes
1answer
101 views

The image turns black when I use the mouse to rotate it

All, This code ...
12
votes
1answer
229 views

Regime Change Stochastic Process

I would like to simulate an Ito process in which the drift and diffusion terms change after hitting a boundary for the first time. For example, a Geometric Brownian Motion X which has 0 drift and ...
2
votes
1answer
61 views

Missing definition of some parts of function?

I have: BeginPackage["Test1`"]; ClearAll[f]; f::usage = ""; Begin["`Private`"]; f[x_AA]:= 1; f[x_BB]:= 2; End[]; EndPackage[]; When later, on a notebook, after ...
1
vote
1answer
102 views

How do I find the constant term of a multivariate polynomial, when (x^0)(y^0)?

So let's say f[x_,y_]:=(2x+2y+1)^2, when I type Coefficient[f[x,y],x y] I recieve 8. But what can I input to recieve 1, when (x^...
4
votes
0answers
80 views

Adding a 3D point using Epilog [duplicate]

I am trying to add a point using the Epilog option with ContourPlot3D. ...
3
votes
0answers
382 views

Fitting data to plot using errors as weights [closed]

I have some enzyme kinetics data that I want to fit to the Michaelis-Menten curve in order to obtain the kinetic parameters of the enzyme. Is it meaningful, statistically and functionally speaking, ...
1
vote
3answers
245 views

Minimize method is not giving minimum. Why?

I was doing an optimization but facing a problem getting what exactly Minimize function do. I run the following code: ...
1
vote
1answer
120 views

How to speed or help Solve[] when it is stuck?

The code below generates a system of equations that I need to Solve[] for {c[5], c[6], c[7], c[8]} in terms of {c[1], c[2], c[3], c[4]}. ...
0
votes
1answer
42 views

About Manipulate : How to make this work properly?

Manipulate[ Plot[PDF[NormalDistribution[mu, sigma], x], {x, -4*sigma, 4*sigma}], {mu, -10, 10}, {sigma, 0, 10} ] I got the following error:
11
votes
2answers
287 views

Built-in symbols that support operator form

In version 10 some built-in symbols are updated to support operator form like the Derivative. For example, Select, ...
0
votes
0answers
78 views

Pulling the boundaries from a Solidworks Profile in Mathematica

I'm currently trying to take a 2d profile generated in SolidWorks and use mathematica to analyze it. I need to pull lines that represent the boundaries of the shape from an image of the shape. . My ...
1
vote
1answer
143 views

Making ReplaceAll faster

I have a list of functions ncalc that is calculated by ...
4
votes
2answers
213 views

definite integration very slow

I have to perform definite integration of function of this kind : ...
1
vote
1answer
539 views

Power::infy: “Infinite expression 1/0. encountered” (ODE Solution using NDSolve)

While solving the following ode, Eq1 = f'''[x] - f'[x]*f'[x] + f[x]*f''[x] - K1*(2 f'[x]* f'''[x] - f[x]* f''''[x] - f''[x]*f''[x]) - f'[x] == 0 with the ...
0
votes
0answers
54 views

FullSimplify cascades too much/groups variables too eagerly

This is something FullSimplify will give: $$\frac{n (s+\text{s2})-\text{a1} g}{\text{a1} (g-\text{a2} s)+s (s+\text{s1}) (s+\text{s2})}$$ I could find better examples where FullSimplify cascades ...
2
votes
2answers
133 views

make trace of a matrix listable?

I have a list of 2 by 2 matrices and I want the list of their traces. I have been using Map[Tr,mylistofmatrices] But I wonder if there is a way to make ...
1
vote
0answers
59 views

NSolve Duration for simultaneous equations solving

At the moment I am asking myself why mathematica gets to point of needing enormous amount of time to solve equations like these when one more "row" or "colum" or both was added in this equations ...
8
votes
1answer
149 views

LogisticSigmoid residue bug?

Bug introduced in 10.0 and fixed in 10.2.0 On version 10.0 for arm: Residue[LogisticSigmoid[z],{z,I Pi}] gives 0 not 1. ...
0
votes
0answers
31 views

How to use PageBreakPalette?

I would like to use PageBreakPallete from http://library.wolfram.com/infocenter/TechNotes/4094/ I did ...
1
vote
1answer
66 views

Table of sections with CellPrint

I am trying to produce a table of sections with each section containing a DynamicModule. My two questions are: (1) How do I produce grouped sections that are folded ...
2
votes
1answer
98 views

Why different output is obtained for the same code (Mathematica 10.1)?

I wrote some code in Mathematica: ...

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