Question

sum elements of matrix if...
Hi, lets say i have two matrices: A=rand(5,10); B=[ones(1,10);3*ones(1,10);ones(1,10);ones(1,10);3*ones(1,10)]; I...

12 years ago | 2 answers | 0

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fixed-point iteration for root finding
a while loop might be a good idea: err_lim = 1e-6; x_new = %initial guess err = err_lim *2; %arbitrary to pass while ...

12 years ago | 0

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how to solve a system of equations with n equation and m unknown (m>n)?
i think fmincon (constrained optimization) will work best... if you try to minimize some error use as the objective: objective=e...

12 years ago | 0

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How to stop nonlinear fitting and obtain the results of fitting at that iteration
the display iter only displays something after an iteration is complete (after all function evaluations of that iteration are do...

12 years ago | 0

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How to stop nonlinear fitting and obtain the results of fitting at that iteration
im no expert on this (sorry) but did you try the 'output' function thingy... i know for most optimizers there is such a thing. i...

12 years ago | 0

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what is the optimal way to build a sparse matrix from row/col index, and value data?
did you check 'sparse'? i think this will do what you want: S = sparse(i,j,s) where i,j,s are your 3 column vectors... htt...

12 years ago | 0

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Optimization: Which algorithms I should choose when it's difficult to define an objective function?
...and if your problem is continuous, then the other optimizers are more usefull (fminsearch, fminunc, fsolve, fmincon,...). ...

12 years ago | 0

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how can i remove this error in matlab?
ermm, what error? and what do you actually want the line to achieve? i mean, the code wants to assign a matrix with blanks to co...

12 years ago | 0

Question

Problem using 'deal' for objective and gradient in comb. with 'DerivativeCheck'
When using optimization tools I usually keep my objective function and gradient function as separate subfunctions and then use '...

12 years ago | 1 answer | 0

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The problem in fminsearch function error
i dont know what you want this to do: x = sym(zeros(6,1)); for i=1:1:6 x(i) = sym(sprintf('x%d',i)); end or: ...

12 years ago | 0

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Question

Calculating stationary distribution of Markov chain
I am calculating the stationary distribution of a Markov chain. The transition matrix P is sparse (at most 4 entries in every co...

12 years ago | 2 answers | 1

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Question

me not like new lay out of this section! (not a question)
i dislike the new lay out of this section, because now only 2 or 3 questions fit on my screen, ie. any overview is lacking and i...

12 years ago | 2 answers | 2

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problem with dynamic optimization solution when increasing the scaling parameter value of the objective function
What is your utility function and how do you scale it? And is zero also your starting value for the controls? The only thing...

12 years ago | 0

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Question about fsolve
first you should try yourself to solve the equation when there is just 1 line (1 a and a_1). see what's happening... and then in...

12 years ago | 0

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Vectorizing finding indexes
Hmmmmm, andrei and jamie: do your solutions only work when Y consists of integers??? In my example Y was just integers, but in f...

12 years ago | 0

Question

Vectorizing finding indexes
hi, i have a vector X and a vector Y (both in ascending order). for every element in X i want the indexes of the values in Y be...

12 years ago | 4 answers | 0

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using fminsearch on several data sets simultaneously
As an alternative you could make an optimization routine for K only. That way you would not need fminunc. It would look very ...

12 years ago | 1

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using fminsearch on several data sets simultaneously
To answer the original post: if you have N data sets, you just have to combine the objective functions for the N data sets, so ...

12 years ago | 0

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Solve non-linear equation with 2 unknowns and lb/ub constraints
to get the min instead of max you have to put a minus in the objective (and yes this is annoying) but if you just try to maxi...

12 years ago | 0

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Question about fsolve
first of all you should delete the /M in the objective, because this only scales your problem in a bad way. another problem cou...

12 years ago | 0

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fminsearch with boundary conditions on parameters
in the file exchange there is an fminsearch with boundaries (fminsearchbnd) i assume you dont have the optimization toolbox, ...

12 years ago | 0

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Non-negativity for unconstrained nonlinear multivariable function
if you want your inputs to be positive, just add them as a lower bound, see documention. For example if your x is a vector of th...

12 years ago | 0

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a question on fsolve
the problem in the first case is that matlab assumes that every x will show up in every equation. In other words, it will try to...

12 years ago | 0

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fmincon and constrains
if you want to minimize all the values in the vector, you can sum them and use that as your objective.... about the not equal...

12 years ago | 0

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fsolve with multidimensional array and x0
if you want to stick more to your orginal formulation: the problem is that your x0 has to be a vector, not an array, so you will...

12 years ago | 1

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syntax of fsolve
you should write it as a function (in either anonymous function, function file or subfunction if your main program is also a fun...

12 years ago | 0

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How do I set my fmincon constraint parameters?
you can insert them as nonlinear constraints (as functions, see the documentation).

12 years ago | 0

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Equation solving problem
im sure we can help you very well with this what do you have so far? or which part is difficult for you? anyway, we have ...

12 years ago | 0

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need help with optimtool
although this does not matter much, you should add an 'end' how do you call obj.m with fmincon? and where did you store obj.m...

12 years ago | 0

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need help with optimtool
apparently you somewhere call a function "obj.m" with an 'double' input and this is not allowed we can't help much more if yo...

12 years ago | 0