# All Questions

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: ...
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 ...
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 ...
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 ...
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 ...
35 views

### How to attach an “handler” to a PopupMenu inside a Manipulate, using the second argument of Dynamic, when the item list is itself variable

I have some trouble evolving from this ...
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 ...
97 views

### Making ReplaceAll faster

I have a list of functions ncalc that is calculated by ...
19 views

...
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 ...
8k views

### How can this confetti code be improved to include shadows and gravity?

Here's some confetti: ...
78 views

### “Power series” in Cos[n*x] for X coordinate of planetary ellipse

Consider the functions below: ...
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: ...
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 ...
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}]] ...
27 views

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

Let that we want to numerically solve the following PDE \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 ...
157 views

### Converting multi variable expression into a function

So I have this rather complicated looking expression ...
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 ...
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 ...
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 ...
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 ...
107 views

### definite integration very slow

I have to perform definite integration of function of this kind : ...
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. ...
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 ...
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 ...
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: ...
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 ...
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 ...
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 ...
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 ...
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]}. ...
54 views

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

All, This code ...
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, ...
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 ...
52 views

### Adding a 3D point using Epilog

I am trying to add a point using the Epilog option with ContourPlot3D. ...
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: ...
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, ...
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, ...
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, ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...