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19 votes
2 answers
1k 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, <...
halirutan's user avatar
  • 113k
-1 votes
3 answers
7k views

How do I determine the maximum value for a polynomial, given a range of x values?

I need to determine the maximum value for y = a x^2 + b x + c, where I know the coefficients and the upper and lower x values. ...
Zolt's user avatar
  • 99
8 votes
2 answers
388 views

Given square matrices A and B, how to solve T obeys Transpose[T]. A . T = B?

Dear Mathematica experts, Given two square matrices, A and B, how do we use Mathematica to solve a matrix T such that T satisfies this matrix equation? (Here we have A,B,T $\in$ general linear matrix ...
zeta's user avatar
  • 251
4 votes
1 answer
6k views

Finding the Minimum value of an interpolating function

I can't seem to use FindMinValue to find the min. value of a curve represented by an interpolating function. For instance the below code generates an interpolating ...
dearN's user avatar
  • 5,351
18 votes
4 answers
1k views

Find the equidistance curve between two curves

I have three function $f(x)=x^x$, $g(x)=\ln(x)^{\ln(x)}$, $h(x)=\ln(x)^2$ and I want to find (numerically) $C$ the center of the circle tangent to the three curves. I think that one way is to find ...
Domenico Modica's user avatar
14 votes
1 answer
967 views

Solving optimal control problem when input is constrained

Given a linear time-invariant system: $$x'(t)=Ax(t)+Bu(t)$$ with initial state $x(0)=x0$ and final state $x(T)=xT$. The performance measure to be minimized is: $$∫_0^Tu(t)^2dt$$ The most important ...
sun's user avatar
  • 141
10 votes
2 answers
1k views

Problem with optimal control and Pontryagin's maximum principle

For dynamic system: $\dot{x}=\frac{df}{dx}+u$ where $f=e^{-x^2}$ It is necessary to develop optimal control, minimizing criterion: $J= \int_{0}^{t_f} ((\frac{df}{dx})^2+u^2) \,dt $ Algorithm: We ...
ayr's user avatar
  • 2,444
6 votes
2 answers
339 views

Counterpart of Maple's LSSolve in Mathematica

I am a great fan of Mathematica. Unfortunately, due to some specific tasks I had to move to Maple. I think it's my lack of info that is not letting me do those tasks. That is why I am asking some ...
naveed's user avatar
  • 339
3 votes
1 answer
2k views

wrong use of _?NumberQ?

I am having trouble with a numerical exercise. Here's a simplified version of my problem. I define two functions to find the solution to two constrained maximization problems: ...
OO_SE's user avatar
  • 335
2 votes
0 answers
218 views

Solving `Integrate` of `InterpolatingFunction` from an `NDSolve`

I am interested in solving a system of Differential Equations, particularly u''[\[Tau]]=-f[t]u[\[Tau]] This system has for initial conditions $u(0)=1/\sqrt{2\cdot ...
Jules Alvarez's user avatar
-1 votes
1 answer
106 views

Solving Nonlinear System

I am solving a $3X3$ non-linear system (posted also in mathematics).After some simplifying assumptions it looks like this: $$K c_1 x_1=(1-x_2)(1-x_3)+a_1(1-x_2)x_3+a_2(1-x_3)x_2+a_3x_3x_2$$ $$K c_2 ...
Weierstraß Ramirez's user avatar
7 votes
3 answers
884 views

Not able to get a solution to a Lagrange Multiplier Equation

I assigned several constrained optimization problems to my calc IV students to solve with Mathematica, but this one is being stubborn. The function to optimize is: f(x,y,z) = y Exp[x-z] with the ...
ChazS's user avatar
  • 71
5 votes
2 answers
317 views

Find maximum of the output from reduce

I am trying to reduce a function in two variables($n_1$ and $n_2$) whose domain is the set of Integers. I get a long list of pairs of values for these two variables(instead of a range). This could be ...
gaganso's user avatar
  • 295
4 votes
1 answer
351 views

best way for finding approximate root of monotonic sawtooth like function

First I will generate such kind of monotonic sawtooth like function called func ...
matheorem's user avatar
  • 17.2k
4 votes
3 answers
1k views

FindRoot constrained to maximum

I am using FindRoot to find the local maximum op some function, by examining where its derivative is zero. However, keeping the starting value the same, sometimes <...
LBogaardt's user avatar
  • 1,605

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