18
votes
1answer
742 views

Bug in Solve (Mathematica 9)

The issue seems to be fixed as of Version 10.1. Just came across the strangest bug under both Mathematica 9.0.0 and 9.0.1. If one enters: ...
1
vote
0answers
42 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 ...
2
votes
3answers
80 views

Perform For-loop and show output which meets a certain criterion

I am new to Mathematica and I have a For loop like so: For[i = 0, i < 15, i++, PowerMod[i, -1, 15]] Currently it doesn't output anything. The calculation I am ...
1
vote
2answers
83 views

Plotting a Hill function

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 ...
8
votes
1answer
111 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 ...
13
votes
2answers
186 views

Can Mathematica produce manipulatable WebGL 3D plots?

I have a 3D plot I produced in Mathematica and I would like to share it with the world in a way that allows my audience to rotate it and interact with it in the broadest possible way. I would like ...
1
vote
1answer
97 views

Making ReplaceAll faster

I have a list of functions ncalc that is calculated by ...
1
vote
2answers
36 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} Should be ...
1
vote
1answer
78 views
1
vote
0answers
32 views

FisherHypergeometricDistribution and WalleniusHypergeometricDistribution, how to specify boundary conditions

I'm trying to write a function that consists of a noncentral hypergeometric distribution. When I'm passing a set of parameters to the function, the following boundary problems occur: ...
10
votes
0answers
91 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
0answers
36 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}]] ...
1
vote
0answers
27 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 ...
3
votes
5answers
157 views

Converting multi variable expression into a function

So I have this rather complicated looking expression ...
0
votes
0answers
54 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 ...
1
vote
1answer
66 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 ...
1
vote
0answers
40 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 ...
1
vote
2answers
34 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 ...
3
votes
2answers
107 views

definite integration very slow

I have to perform definite integration of function of this kind : ...
0
votes
0answers
75 views

ODE fitting to dataset

So, I have a ODE system, it is a complex biochemical kinetic mechanism with six species changing over time. ...
0
votes
0answers
41 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 ...
1
vote
1answer
88 views

Defining Solutions to FindRoot a functions of parameters-Part II

Here's a similar question as the the preceding question with the same title, but this time with vectors, which I need to use. I followed the suggestion in the answer the the previous question, but it ...
5
votes
3answers
195 views

Generate a list of equations of curves and plot them

I want to plot a series of lines. This is how I do it: ...
12
votes
1answer
372 views

Greek variables in 10.0.1

Bug introduced in 10.0.1 and fixed in 10.0.2 10.0.1 under Ubuntu 12.04 x64 .... Does everybody get greek variables emboldened? Is anybody aware of how to revert to previous normal display? The ...
-3
votes
1answer
69 views

Interpolate/Extrapolate a gate charge curve from 2 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
44 views

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

I have a UI with DynamicModules. I have a progress bar, whenever the varibale progress updates, the ...
0
votes
0answers
40 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
68 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]}. ...
16
votes
1answer
362 views

A better simplification function

I am creating this question and posting an answer to it as a help for those who have problems with Mathematica simplification oddities that appear in many other questions on the site. First of all, ...
2
votes
1answer
42 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 ...
2
votes
0answers
52 views

Adding a 3D point using Epilog

I am trying to add a point using the Epilog option with ContourPlot3D. ...
1
vote
3answers
76 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: ...
9
votes
2answers
176 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, ...
13
votes
2answers
425 views

Determining the default Method used in optimization and root-finding algorithms

Is it possible to extract the Method which is used in functions like NMinimize, FindRoot, ...
3
votes
0answers
44 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
1answer
59 views

Scaling vectors in an animated vector field

I want to animate a VectorPlot3D. But, Mathematica rescales the vectors in every frame. Can you scale them all to one fix point? For example, scale the vectors on ...
-7
votes
0answers
31 views

i need generalized code for genetic algorithm(an optimization technique)? [on hold]

I'm working on GA coding to optimize the locators position in fixturing system to minimize the error in precision manufacturing.I need generalize code for GA (including random population ...
0
votes
0answers
36 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 ...
0
votes
1answer
90 views

How to stop a .sh script that calls multiple Mathematica scripts?

When I press Ctrl + C in a linux console running a Mathematica script, it doesn't stop. Instead it brings a console where I am supposed to type either quit, or ...
17
votes
1answer
291 views

math.exe vs wolfram.exe vs MathKernel.exe vs WolframKernel.exe (running scripts on Windows)

I generally consider Mma documentation very good. However, it is startlingly difficult to find useful information on running Mma batch scripts, especially on Windows. So ... just what would I enter ...
0
votes
0answers
61 views

Finding the numerical solution to a polynomial of a high degree [on hold]

I would like to numerically solve the following equation for ρ and use the obtained values of ρ to calculate the values of VR ...
0
votes
2answers
317 views

Does the equation have two roots? [on hold]

I want to solve the equation $$-x^2+\sqrt{2-x^2} \left(x^2+2 x-1\right)+2 x+5=0.$$ I tried ...
1
vote
1answer
55 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
59 views

NDSolve and assuming

I am trying to solve the system of PDE with NDSolve and I got an error message like this NDSolve::deqn: "Equation or list of equations expected instead of ...
-2
votes
0answers
15 views

How many workers each company have? [on hold]

If total there are 90 workers between 2 companies and one company have 16 more workers then the other. How many each company have?
0
votes
1answer
53 views

Finding the points where the derivative is zero [on hold]

I want to find points where the derivative of a function is zero. Therefore, I discretize the waveform (vbusa) and have substituted time and voltage values into the ...

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