Linked Questions

0
votes
1answer
52 views

Count intersections of two non-polynomial functions [duplicate]

I have two Bessel functions, and I need to be able to count the number of intersections if both functions are plotted dependent upon the same variable. I can use FindRoot or FindInstance to get one ...
18
votes
6answers
4k views

About multi-root search in Mathematica for transcendental equations

I have some questions for multiroot search for transcendental equations. Is there any clever solution to find all the roots for a transcendental equation in a specific range? Perhaps ...
20
votes
6answers
2k views

Finding the intersection of a curve with an interpolation function

There are no issues trying to find the intersection points of two defined curves. ...
34
votes
3answers
2k views

Identifying critical points/lines of 2/3D image/cubes

Upshot I am interested in identifying critical points of a 3D field/cubes (maxima, minima, tube-like and wall-like saddle points) and 2D field/image (maxima, minima, saddle points). I.e. the ...
10
votes
3answers
633 views

Finding “Maxima” and “Minima” on a B-Spline

I need to find the "Maxima" and "Minima" on a B-Spline or more correct the points where the 2nd components of the derivate equal zero. For example: ...
10
votes
1answer
881 views

How do I find all the solutions of three simultaneous equations within a given box?

Sometimes, one needs to find all the solutions of three simultaneous nonlinear equations in three unknowns $$\begin{align*}f(x,y,z)&=0\\g(x,y,z)&=0\\h(x,y,z)&=0\end{align*}$$ within a ...
9
votes
2answers
1k views

RootSearch for complex or multiple equations

First the background. I'm trying to solve for the roots of a rather messy complex equation. This is not the exact equation, but it's a decent (simpler) stand in: ...
2
votes
1answer
971 views

FindMaxValue and FindMaximum - how to find GLOBAL maximum and not just LOCAL maximum

I will not be able to provide a simple minimum working example here as this seems to be very specific. I have an interpolating function which I substituted into a PDE and then plot said PDE at a ...
3
votes
2answers
822 views

Numerically Solving two dependent Transcendental Equations

I need to solve a system similar to the following (Except it is quite large. Solving this ought to do the job): $$ \tan[2f(t)] = 1+ t^2\ $$ and $ f(t) $ is $ k $, such that$$ \tan[2kt]-(1+k^2) = 0\ ...
7
votes
1answer
646 views

Using Mathematica to help to determine the consistency of and numerically solve systems of non-linear equations

The formal problem The question I am about to ask is applicable to many scientific and engineering problems. In short, I am bout to ask for pointers and practical advice for Mathematica beginners who ...
2
votes
1answer
215 views

Plotting Zeros of a Complex Variable

I'm trying to plot the zeros within a certain distance from the origin using Mathematica of a given function (in my case, partial sums of the Zeta Function). I've tried plugging in simple functions, ...
3
votes
1answer
315 views

HarmonicNumber problem

I am looking for all the roots of HarmonicNumber, in the domain [-30, 1] and [0, 6000] for the real and imaginary parts, respectively, and where the parameter ...
1
vote
1answer
343 views

How to get a solution set of a nonlinear system of equations?

I'm trying to find the solution set of {x, y} variables for the following system of equations: ...
7
votes
0answers
437 views

Creating and using an explicit piecewise function in a convenient way

I have a set of data points that define a function in the form curvePts = {data1,data2,...} where ...
1
vote
1answer
359 views

How to guess initial complex value for FindRoot

I have to solve a transcendental equation for a parameter, say $\beta$. Now, the $\beta$ has a range from $ik$ to $k$ where $i$ is the usual imaginary root $\sqrt{-1}$ and $k$ is a real number. ...

15 30 50 per page