All Questions
Tagged with equation-solving mathematical-optimization
211
questions
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61
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Finding the symbolic root of a non-linear function with fractional exponents
Define $f(x, a, t) = (x-t)^a - \frac{x^2}{2}$ where $x>0$ is the main variable of interest and $\alpha \in (0,1)$ is the parameter of curvature:
...
0
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0
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49
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Optimization problem with complex and real values
I have the following optimization problem:
$\underset{{{a}_{1}},...,{{a}_{m}}}{\mathop{\max }}\,\parallel \sum\limits_{n=1}^{N}{{{a}_{n}}}{{\varpi }_{n}}{{e}^{j{{\theta }_{n}}}}{{\varphi }_{n}}{{\...
2
votes
0
answers
192
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How to approximate an exponential series?
Consider the following expression
$$
y_j= \sum_{k=0}^{L} \frac{e^{-\sum_{i=-k}^k(k-|i|)x_{j+i}}-e^{-\sum_{i=-k}^k(k+1-|i|)x_{j+i}}}{\sum_{i=-k}^k x_{j+i}}\tag{1}
$$
for $1\leq j \leq L$. Given smooth ...
- 4,903
1
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1
answer
130
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Minimize is returning unevaluated for a simple positive integer domain problem [closed]
I don't understand why the following Minimize code is returning unevaluated. I believe I have it coded properly and the expected minimum is $x=14$ and $y=1$.
<...
- 2,444
0
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197
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4
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2
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126
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Representing pairs of values that lead to a constant
I have the following expression:
$Q=\frac{\sqrt{rc}}{1+r(1+K)}$
Q and K are constant values. Basically I want to plot a graph that shows me all the combinations of r and c that verify the equation. ...
1
vote
0
answers
97
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Optimizing my code to solve nonlinear system
I have solved a non-linear system using Eliminate[] and Solve[], using a really nice answer found here I am able to use ...
0
votes
1
answer
72
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Find solutions after using Eliminate
I have used Eliminate[] to reduce a system of equations as found here, I then proceeded to verify that indeed my system has zeros using this code. My question is, ...
-1
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1
answer
106
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Solving Nonlinear System
I am solving a $3X3$ non-linear system (posted also in mathematics).After some simplifying assumptions it looks like this:
$$K c_1 x_1=(1-x_2)(1-x_3)+a_1(1-x_2)x_3+a_2(1-x_3)x_2+a_3x_3x_2$$
$$K c_2 ...
3
votes
2
answers
209
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Fitting an exponential system
Consider the following system over a periodic array, where $1\leq j\leq n$,
$$
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
0
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1
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91
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Finding only non-negative roots with FindRoot
Given an arbitrary function F, how do I force FindRoot to look only for non-negative roots, returning nothing otherwise?
- 4,903
2
votes
1
answer
55
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Using the result of Solve as a function of parameters
I am trying to find b2 maximising a function I named 'EG1EUB'. And 'EG1EUBb2' is the frist order condition. Based on my understanding, Solve gave me a single solution saying that b2 is the second root....
- 45
2
votes
1
answer
101
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Can I solve a system for a postive semidefinite variables?
I have the following system, where I want to find the solution set consisting of real, nonzero, symmetric positive semidefinite matrices $G$ and $DD$ such that the block matrix $X$ defined below is ...
- 315
0
votes
1
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281
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Solving an equation involving exponential function
I have an equation
$$ c \tan \left(\theta_{\mathrm{OPT}}\right)+\frac{a b A \exp \left(-b\left[\theta_{\mathrm{OPT}}-a\right]\right)}{\left[a \exp \left(-b\left[\theta_{\mathrm{OPT}}-a\right]\right)+1\...
- 3
0
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2
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86
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how i put condition to sure that values of outputs in FindRoot?
i want to put condition in this like x>0,0<y<1
FindRoot[{Exp[x - 2] == y, y^2 == x,x > 0 && 0 < y < 1}, {{x, 1}, {y, 1}}]
but it dosen't ...
- 369