All Questions
10
questions
0
votes
2
answers
109
views
Why can't NSolve find values that FindInstance can?
I am trying to solve for \[Epsilon], given three input paramters n, x and ...
- 496
3
votes
2
answers
209
views
Fitting an exponential system
Consider the following system over a periodic array, where $1\leq j\leq n$,
$$
y_j= \sum_{k=0}^m \frac{e^{-\sum_{|i|\leq k}(k-|i|)x_{j+i}}-e^{-\sum_{|i|\leq k}(k+1-|i|)x_{j+i}}}{\sum_{|i|\leq k} x_{j+...
- 4,903
4
votes
0
answers
137
views
Solving or Minimizing the Norm of the matrix equation $M^TAM - M^TB - B^TM =C$
I am trying to solve the matrix equation $M^TAM - M^TB - B^TM=C$ where I know A, B and C. My unknown matrix is M which has the special form that all the rows and columns sum to zero.
i.e. I have four ...
- 777
0
votes
0
answers
113
views
Solving a system of equations as part of maximizing a multivariable function
This is my code
...
- 496
2
votes
0
answers
59
views
How to find the regions for which the derivative of my function changes sign?
I have an energy function of the angles of the electrons' spins. th1 is vector with (2l+2) elements and each element represents the angle of an individual electron spin. I need to eventually find the ...
2
votes
2
answers
101
views
Wolfram Cloud memory limit exceeded with complex Lagrange multipliers
I'm new to the forum and I have problems when I try to run this code. The computation exceeds the limit of my plan.
This is my code. What can I do?
...
- 21
2
votes
1
answer
140
views
Unable to use `Solve` to solve simultaneous equations, or use `Maximize` for exact maximum solution
Mathematica has found that the maximum of the following function is negative using NMaximize, but I am trying to prove that the maximum is negative (i.e. that the ...
- 47
2
votes
0
answers
80
views
Using FindMinimum to solve equations as constraints
As suggested here, a system of equations can be seen as constraints in a minimization procedure with a zero cost function.
For instance:
...
- 14.4k
1
vote
1
answer
329
views
Improving strategy to solve this constrained root-finding problem
I am looking for roots of the function eqs defined below. It has $2k$ unknowns and returns a vector of $2k-1$ components.
The sole purpose of the following block ...
- 14.4k
3
votes
1
answer
188
views
Speeding up constrained optimization problem solving
I have a problem on my homework with Lagrangian multipliers that Mathematica has now been bashing at fruitlessly for 10 minutes. I'm not sure whether I did something horribly wrong codewise, but it's ...
- 562