# All Questions

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### Different Results from Simplify, dependent on explicit vs computed rules

Can anybody explain why these two pieces of code are giving me different results? Heres the inputs: ...
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### How to calculate the derivative at a point of a non-integrable multivariable function?

I want to integrate this function with respect to θ1 and then take the derivative of that function with respect to n. Since the ...
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### How to calculate the value of financial derivatives [on hold]

I want to loop through all of the put and calls available for each of the derivative types as listed by calling: FinancialDerivative[] I need to eliminate the ...
138 views

### How to tell Mathematica to get the real-only inverse function?

The problem I have is that Mathematica seems to play better with complex numbers so that the result of N[InverseFunction[Function[x,x^3]][-1]] is ...
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### Discrete Fourier Transform: help on how to convert x axis in to the frequency when I have a set of data samples [duplicate]

I have a huge data set (400000 sample) and when I plot them ListLinePlot[Au4, PlotRange -> {All, All}] I used the following code to Fourier transform it ...
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I want to do image processing using the Wolfram Language on a web app hosted on the Wolfram Cloud. The user must be able to upload a PNG image to the Wolfram Cloud, how can I set this up? I've ...
130 views

### How does Mathematica detect the number of cores in a system?

I'm running Mathematica 10.3.1.0 on a machine with 16 cores, but Mathematica (in the Parallel settings) says "Number of processor cores is 8." It's a 16-core Opteron 6300 chip on an Ubuntu system. All ...
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### Combining two list function (Is it the best way?)

Suppose I have two list, ...
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### Solve a nonlinear PDE equation with a Neumann boundary condition

I am trying to use Mathematica 10 to solve a PDE $$u_t=u_{xx}+u_{yy}+u(1-u),$$ in the unit disk $(x,y) \in D=\{(x,y):x^2+y^2<1\}$, with the Neumann boundary condtion \frac{\partial u}{\partial ...
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### How to find the real values of the parameter a, so that the inequation doesn't have positive solutions? [migrated]

The inequation is the following: (x^2 - 6ax + 2x - 5a - 1) / (x+a+1) < 0 If we write this inequation like a/b <0, I may say that for a=0, I found that X1=3a -1-sqrt(9a^2-a+2) X2=3a ...
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### Error given by the Clear function

I'm trying to clear out some variables that I've previously used, so that I can use them again. I tried this in a different notebook and it worked, however, now, a command like : ...
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### Is the free Mathematica Trial Version a full version? [on hold]

There is a trial version of Mathematica in the Wolfram website, which can be downloaded for free with a license valid for 15 days. Is this version of Mathematica a "full version"? That is, during ...
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### How to plot linear term of a function expanded by Taylor seires in Mathematica?

I am quite new in Mathematica and I am trying to plot a linear term of a particular function in Mathematica. I have tried something like this: ...
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### Trouble solving a system of 2 ODE's with NDSolve

I'm trying to solve a system of two coupled second-order ordinary differential equations using Mathematica's NDSolve. The functions of r that appear in the equations are ...
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### replacing complex numbers

I know: I'm going to make a poor showing, but really I can't understand this: a is an expressione whose FullForm is ...
53 views

### Conditional probability syntax [on hold]

What syntax do I use to compute this in Mathematica? Game of Yahtzee: 1. Suppose you get three 5’s on the first roll. What is the probability of rolling the other two dice and completing the Yahtzee ...
141 views

### How to get the frequency information of an mp3 audio?

I have: music = Import["http://www.qlcoder.com/uploads/145425353234642.mp3", "mp3"] Then I get: But what I want to get is ...
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### Arrowheads cover the end of the ticks

When arrowheads are added to the axes, the ends of the ticks are covered by the arrowheads, e.g., ticks for $1$ disappear in the plot below, ...
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### Label multiple Data in Set of plots

in this simplified example I defined several data and plotted them at once to reduce typing work. Unfortunately I cannot find the syntax or option to label/ name each data array, which all belong to ...
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### Deleting vertices from Graph and preserving Structure?

My goal is to remove vertices from graphs (and the edges from them) and then take GraphComplement to find out cut sets in graphs with sink and source such as here. So How can I delete vertices from a ...
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### Plot multiple functions with different but overlapping intervals

Suppose I numerically solve a differential equation by using sol = ParametricNDSolve[{y'[x] == b y[x], y[0] == 1}, y, {x, 0, 0.3}, {b}] And then I want to plot ...
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### Random bipartite graphs?

RandomGraph[{n,m}] generates a random graph with $n$ vertices and $m$ edges. I want to generate a random bipartite graph, like ...
107 views

### Solving a quasi- or nonlinear PDE

Is the following PDE solvable in mathematica 9? When i solve it, the DSolve command does not do anything. ...
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### Manipulate aborts the computation of NDSolve with the Piecewise function after curtain time [on hold]

I'm facing the problem with performance: Manipulate is working fine till end time =60 sec, after that it aborts. There is NDSolve inside Manipulate with Piecewise function, and the plot of the ...
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### Interpolate the discrete list into continuous function

I have a data whose list plot shows up following graph I would like to interpolate the missing data and make the function continuous but for particular x-coordinate there is multiple values of $y$ ...
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### NelderMeadMinimize for 2D Gaussian fitting

I would like to fit a large number (10^5-10^6) of small images to 2D gaussians by taking advantage of the NelderMeadMinimize package from Oleksandr: Shaving the last 50 ms off NMinimize. The ...
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### an odd degree node . [on hold]

Let $v$ be an odd degree node. Consider the longest walk starting at $v$ that does not repeat any edges ( though it may omit some ) . Let $w$ be the final node of the walk . Show that $v$ $\neq$ $w$. ...
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### extract data from a graph image

How do I convert the following image graph into data (if possible into function)? I checked this answer and found that my problem is grid and plot have same color.
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### Visualize how a function varies as its parameters vary [on hold]

I'm quite new to Mathematica, so maybe i havent figured out the right help file to look or the right function. I apologize if thats the case, but I would like to be pointed in the right direction if ...
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### Prevent Dynamic from behaving dynamically until notebook evaluated

If a notebook containing a = {1, 2}; Dynamic[a[[2]]] (* 2 *) is executed, closed, and then opened in a new session, it yields along with the expected error ...
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### Integration by using NDSolve [duplicate]

I have no idea how to calculate the problems. For example consider following differential equation (DE): ...
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### What are the time and space complexities of Classify/Predict?

Does anyone have knowledge of the O(n) time & space complexities for various model types supported by Classify[] and ...
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### How can I add a checkbox to a Manipulate expression?

I'm looking for a simple example about how to add a simple On-Off switch in a manipulate function. More specifically, I defined a curve with two parameters. One is a continuous parameter that is ...
52 views

### Is it possible to visualize something in for loop? [closed]

Hi I have the following code: ...
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### 3D Vector Plot with multiple data points

I have this code: ...
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### For Loop clarification [closed]

I have the following dataset: ...
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### Can't load Geometry package [closed]

I am trying to use << GeometryRotations; but I got this message Get::noopen: Cannot open GeometryRotations`. >>". How I can solve this problem?
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### Simple grouping equations [closed]

I'm new in the Mathematica world. A very basic question. I have been using the command Eliminate on a set of equations as follow: ...
55 views

### How to compare two polygons?

I have these polygon points which are like these: ...
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### Imaginary part of complex number, nothing works?

I want to find the imaginary part of the complex number (a+i*b). say I have a function in the following form: ...
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### Sum of difference between dates do not match [closed]

The formula used was years of 365 days and months with 30 days. The days of the sum column are correct. The column sum of the hazard in years, months and days also is correct . But when I verify that ...
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### Using Solve with NIntegrate [duplicate]

I have a function defined as a numerical integral of a parameter. When I try to solve for the parameter Mathematica complains that the integrand has evaluated to a non-numerical value (which makes ...
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### How can I calculate the root of any order of power series

How can I calculate the root of any order of power series with Mathematica. Here I insert every quantity by hand. But I want to give a, ...
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### Forcing equal scale in RegionPlot3D [duplicate]

I want the following 3D graph using RegionPlot3D. But the following code does not give me uniform scales on different axes. ...
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### Is there a way to find the values of x for a graph in a given area?

Sorry for my wording, I'm not sure what the proper term for this is. I want to find the sections of x for which the graph of some function, f(x), is in a given area. For an example of what I'm ...