5
votes
1answer
163 views

Solution to $y = x^x (1-x)^{(1-x)}$ for $x$ [closed]

Does anyone have any insight to a symbolic Mathematica solution to this equation for $x$ in terms of y? Symbolic of any sort, just not numeric. $$y = x^x (1-x)^{(1-x)}$$
6
votes
1answer
34 views

How to force evaluation of an expression with Part left unnevaluated?

My goal is to minimize a real valued multi-variable function averageFreeEnergyDensity. The function accepts an integer argument ...
2
votes
2answers
60 views

Graph not drawing after VertexDelete

I'm very new to Mathematica and am currently trying the VertexDelete function, but after using it, my graph isn't drawing. Input: ...
1
vote
3answers
95 views

Use Do to evaluate an expression over two indices $i \ne j$ (over a list of tuples)?

I have an expression of the form: expr1[i_,j_] = Sum[\[Beta][j]*\[Phi][i, j]* C[i] I would like to evaluate this expression over i=1:4, j=1:4 with i!= j. One ...
0
votes
0answers
31 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
135 views

Parametrize a circle as a tube?

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

How to determine why Solve[] failed?

I don't know what to make of Solve[] failing on this: ...
-1
votes
0answers
24 views

Delete integer cases that contain specified number [duplicate]

I have a sequence generated with this RecurrenceTable function: RecurrenceTable[{a[n + 1] == 7 a[n], a[1] == 3}, a, {n, 1, 10}] and I would like to remove the ...
2
votes
0answers
35 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
347 views
0
votes
0answers
52 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
154 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) = ...
7
votes
1answer
52 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., ...
-4
votes
0answers
42 views

problem with this assignment, can you help? [closed]

Give approximative values on the all the roots to the equation x = 3sinx. Place the the answers in-growing order
5
votes
3answers
104 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 ...
2
votes
2answers
126 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
69 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 ...
0
votes
0answers
25 views

Constraints for LP [closed]

Im fairly new to mathematica and I'm writing a minimization problem with constraints: ...
1
vote
3answers
77 views

ListPlot the results of FindMaximum [on hold]

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 ...
5
votes
4answers
109 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
137 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
128 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 ...
1
vote
1answer
79 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
37 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 ...
18
votes
4answers
762 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
34 views
2
votes
1answer
93 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
0answers
112 views

Wrong Limit in Mathematica 10.0.0

Limit[(Log[(3+Sqrt[5])/2]/(2*Log[(1+Sqrt[5])/2]))^(-1-2*n), n -> Infinity] Mathematica (wrong) output: 0 But this is ...
1
vote
2answers
237 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 ...
1
vote
0answers
60 views

How to incorporate the boundary conditions into the differentiation scheme in MMA?

Let that we want to numerically solve the following PDE \begin{equation}\label{sde} -r V(S,t)+r S \frac{\partial V(S,t)}{\partial S}+0.5 S^2 \text{sigma}^2 \frac{\partial ^2V(S,t)}{\partial ...
2
votes
1answer
59 views

Generating and Imaging of the water molecules with Graphics3D

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}]] ...
5
votes
0answers
116 views

Wrong Limit with LaguerreL

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
259 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
92 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
50 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 ...
3
votes
1answer
172 views

ODE fitting to dataset

So, I have a ODE system, it is a complex biochemical kinetic mechanism with six species changing over time. ...
-1
votes
0answers
62 views

convergence problem - triple integral

I have a problem in convergence ... for i=j=5 is enough to calculate what i want. But for os11[100,5,5]=1.59 ( 1.58 is the real ...
3
votes
5answers
171 views

Converting multi variable expression into a function

So I have this rather complicated looking expression ...
1
vote
1answer
81 views

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

All, This code ...
12
votes
1answer
177 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
45 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
72 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 ...
2
votes
0answers
58 views

Adding a 3D point using Epilog [closed]

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

Fitting data to plot using errors as weights

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, ...
0
votes
0answers
48 views

n dimension vector expression in mathematica

I have a question about how to write the formula in Mathematica. If $w$ is $n$-dimensional vector, with each element as $w_i : i=1,2,3,...n$ and $n$ is symbol, how to write it as vector in ...
-7
votes
0answers
53 views

I need generalized code for genetic algorithm(an optimization technique)? [closed]

I'm working on GA coding to optimize the locators position in fixturing system to minimize the error in precision manufacturing.Basically my work is the extension of article "An analytical model for ...
1
vote
3answers
91 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: ...
-2
votes
0answers
17 views

How many workers each company have? [closed]

If total there are 90 workers between 2 companies and one company have 16 more workers then the other. How many each company have?
1
vote
1answer
73 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
24 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:

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