# All Questions

87 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 ...
84 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 ...
147 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: ...
214 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 ...
229 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 ...
96 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: ...
51 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 ...
921 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 ...
53 views

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117 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 ...
222 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: ...
439 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 ...
144 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}]] ...
216 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 ...
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: ...
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 ...
67 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 ...
325 views

### ODE fitting to dataset

So, I have a ODE system, it is a complex biochemical kinetic mechanism with six species changing over time. ...
194 views

### Converting multi variable expression into a function

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

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

All, This code ...
227 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 ...
60 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 ...
100 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 ...
80 views

### Adding a 3D point using Epilog [duplicate]

I am trying to add a point using the Epilog option with ContourPlot3D. ...
329 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, ...
235 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: ...
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]}. ...
41 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:
279 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, ...
75 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 ...
142 views

### Making ReplaceAll faster

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

### definite integration very slow

I have to perform definite integration of function of this kind : ...
500 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 ...
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 ...
131 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 ...
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 ...
146 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. ...
30 views

### How to use PageBreakPalette?

I would like to use PageBreakPallete from http://library.wolfram.com/infocenter/TechNotes/4094/ I did ...
63 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 ...
98 views

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

I wrote some code in Mathematica: ...
93 views

### Fast construction and reshaping of large tensors

I'm trying to construct a large matrix which is derived from some higher rank tensor (the rank of interest to me changes case by case, so it needs to be a general method). Currently, the process of ...
62 views

### How to change size of whole input?

I would like to change size of font of input/output. I see that I can just click on options of single input and set size, but I don't want to do this separately for every line. Could someone help me ...
192 views

### How to speed up a symbolic integration

I have a question about an integral. I wanna integrate this: ...
69 views

### CharacteristicPolynomial returns 0

I have a following matrix. ...
53 views

### Pattern matching & simple replacement

I have a question about an expression that I want to modify. Here is the expression: ...
350 views

### Does the equation have two roots? [closed]

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 ...
74 views

### How can I plot bollinger bands on financial time series? [closed]

I can't find any options for this in CandlestickChart[], but it's a pretty basic measure, is it not supported?
384 views

### Solve for x given an interpolation function, y

Given a list of data, lst={{x1,y2},{x2,y2},...,{xn,yn}} and the interpolation function fun, y=Interpolation[lst] which ...