Solves a multiobjective goal attainment problem
x = fgoalattain(fun,x0,goal,weight) +x = fgoalattain(fun,x0,goal,weight,A,b) +x = fgoalattain(fun,x0,goal,weight,A,b,Aeq,beq) +x = fgoalattain(fun,x0,goal,weight,A,b,Aeq,beq,lb,ub) +x = fgoalattain(fun,x0,goal,weight,A,b,Aeq,beq,lb,ub,nonlcon) +x = fgoalattain(fun,x0,goal,weight,A,b,Aeq,beq,lb,ub,nonlcon,options) +[x,fval] = fgoalattain(...) +[x,fval,attainfactor] = fgoalattain(...) +[x,fval,attainfactor,exitflag] = fgoalattain(...) +[x,fval,attainfactor,exitflag,output] = fgoalattain(...) +[x,fval,attainfactor,exitflag,output,lambda] = fgoalattain(...)
a function that accepts a vector x and returns a vector F
a nx1 or 1xn matrix of double, where n is the number of variables.
a nil x n matrix of double, where n is the number of variables and
a nil x 1 matrix of double, where nil is the number of linear
a nel x n matrix of double, where n is the number of variables
a nel x 1 matrix of double, where nel is the number of linear
a nx1 or 1xn matrix of double, where n is the number of variables.
a nx1 or 1xn matrix of double, where n is the number of variables.
a function, the nonlinear constraints
a list, containing the option for user to specify. See below for details.
a nx1 matrix of double, the computed solution of the optimization problem
a vector of double, the value of functions at x
The amount of over- or underachievement of the goals,γ at the solution.
a 1x1 matrix of floating point integers, the exit status
a struct, the details of the optimization process
a struct, the Lagrange multipliers at optimum
fgoalattain solves the goal attainment problem, which is one formulation for minimizing a multiobjective optimization problem. +Finds the minimum of a problem specified by: +Minimise Y such that
+The solver makes use of fmincon to find the minimum.
+The fgoalattain finds out the maximum value of Y for the objectives evaluated at the starting point and +adds that as another variable to the vector x +This is passed to the fmincon function to get the optimised value of Y +Hence, the algorithm used mainly is "ipopt" to obtain the optimum solution +The relations between f(x), Y, weights and goals are added as additional non-linear inequality constraints
+The options allows the user to set various parameters of the Optimization problem. +It should be defined as type "list" and contains the following fields. +
By default, the gradient options for fminimax are turned off and and fmincon does the gradient opproximation of minmaxObjfun. In case the GradObj option is off and GradConstr option is on, fminimax approximates minmaxObjfun gradient using numderivative toolbox.
+If we can provide exact gradients, we should do so since it improves the convergence speed of the optimization algorithm.
+Furthermore, we must enable the "GradObj" option with the statement : +
minimaxOptions = list("GradObj",fGrad); | ![]() | ![]() |
The constraint function must have header : +
+where x is a n x 1 matrix of dominmaxUbles, c is a 1 x nni matrix of doubles and ceq is a 1 x nne matrix of doubles (nni : number of nonlinear inequality constraints, nne : number of nonlinear equality constraints). +On input, the variable x contains the current point and, on output, the variable c must contain the nonlinear inequality constraints and ceq must contain the nonlinear equality constraints. +By default, the gradient options for fminimax are turned off and and fmincon does the gradient opproximation of confun. In case the GradObj option is on and GradCons option is off, fminimax approximates confun gradient using numderivative toolbox.
+If we can provide exact gradients, we should do so since it improves the convergence speed of the optimization algorithm.
+Furthermore, we must enable the "GradCon" option with the statement : +
minimaxOptions = list("GradCon",confunGrad); | ![]() | ![]() |
The constraint derivative function must have header : +
+where dc is a nni x n matrix of doubles and dceq is a nne x n matrix of doubles. +The exitflag allows to know the status of the optimization which is given back by Ipopt. +
For more details on exitflag see the ipopt documentation, go to http://www.coin-or.org/Ipopt/documentation/
+The output data structure contains detailed informations about the optimization process. +It has type "struct" and contains the following fields. +
The lambda data structure contains the Lagrange multipliers at the end +of optimization. In the current version the values are returned only when the the solution is optimal. +It has type "struct" and contains the following fields. +
function f1=gattainObjfun(x) +f1(1)=2*x(1)*x(1)+x(2)*x(2)-48*x(1)-40*x(2)+304 +f1(2)=-x(1)*x(1)-3*x(2)*x(2) +f1(3)=x(1)+3*x(2)-18 +f1(4)=-x(1)-x(2) +f1(5)=x(1)+x(2)-8 +endfunction +x0=[-1,1]; + +goal=[-5,-3,-2,-1,-4]; +weight=abs(goal) +gval = +[- 0.0000011 +- 63.999998 +- 2.0000002 +- 8. +3.485D-08] +z = +[4. 3.99] + +Run fgoalattain +[x,fval,attainfactor,exitflag,output,lambda]=fgoalattain(gattainObjfun,x0,goal,weight) | ![]() | ![]() |
Solves a multi-variable optimization problem on a bounded interval
xopt = fminbnd(f,x1,x2) +xopt = fminbnd(f,x1,x2,options) +[xopt,fopt] = fminbnd(.....) +[xopt,fopt,exitflag]= fminbnd(.....) +[xopt,fopt,exitflag,output]=fminbnd(.....) +[xopt,fopt,exitflag,output,lambda]=fminbnd(.....)
a function, representing the objective function of the problem
a vector, containing the lower bound of the variables of size (1 X n) or (n X 1) where 'n' is the number of Variables, where n is number of Variables
a vector, containing the upper bound of the variables of size (1 X n) or (n X 1) or (0 X 0) where 'n' is the number of Variables. If x2 is empty it means upper bound is +infinity
a list, containing the option for user to specify. See below for details.
a vector of doubles, containing the the computed solution of the optimization problem.
a scalar of double, containing the the function value at x.
a scalar of integer, containing the flag which denotes the reason for termination of algorithm. See below for details.
a structure, containing the information about the optimization. See below for details.
a structure, containing the Lagrange multipliers of lower bound and upper bound at the optimized point. See below for details.
Search the minimum of a multi-variable function on bounded interval specified by : +Find the minimum of f(x) such that
+The routine calls Ipopt for solving the Bounded Optimization problem, Ipopt is a library written in C++.
+The options allows the user to set various parameters of the Optimization problem. +It should be defined as type "list" and contains the following fields. +
The exitflag allows to know the status of the optimization which is given back by Ipopt. +
For more details on exitflag see the ipopt documentation, go to http://www.coin-or.org/Ipopt/documentation/
+The output data structure contains detailed informations about the optimization process. +It has type "struct" and contains the following fields. +
The lambda data structure contains the Lagrange multipliers at the end +of optimization. In the current version the values are returned only when the the solution is optimal. +It has type "struct" and contains the following fields. +
//Find x in R^6 such that it minimizes: +//f(x)= sin(x1) + sin(x2) + sin(x3) + sin(x4) + sin(x5) + sin(x6) +//-2 <= x1,x2,x3,x4,x5,x6 <= 2 +//Objective function to be minimised +function y=f(x) +y=0 +for i =1:6 +y=y+sin(x(i)); +end +endfunction +//Variable bounds +x1 = [-2, -2, -2, -2, -2, -2]; +x2 = [2, 2, 2, 2, 2, 2]; +//Options +options=list("MaxIter",[1500],"CpuTime", [100],"TolX",[1e-6]) +//Calling Ipopt +[x,fval] =fminbnd(f, x1, x2, options) | ![]() | ![]() |
//The below problem is an unbounded problem: +//Find x in R^2 such that it minimizes: +//f(x)= -[(x1-1)^2 + (x2-1)^2] +//-inf <= x1,x2 <= inf +//Objective function to be minimised +function y=f(x) +y=-((x(1)-1)^2+(x(2)-1)^2); +endfunction +//Variable bounds +x1 = [-%inf , -%inf]; +x2 = []; +//Options +options=list("MaxIter",[1500],"CpuTime", [100],"TolX",[1e-6]) +//Calling Ipopt +[x,fval,exitflag,output,lambda] =fminbnd(f, x1, x2, options) | ![]() | ![]() |
Solves a multi-variable constrainted optimization problem
xopt = fmincon(f,x0,A,b) +xopt = fmincon(f,x0,A,b,Aeq,beq) +xopt = fmincon(f,x0,A,b,Aeq,beq,lb,ub) +xopt = fmincon(f,x0,A,b,Aeq,beq,lb,ub,nlc) +xopt = fmincon(f,x0,A,b,Aeq,beq,lb,ub,nlc,options) +[xopt,fopt] = fmincon(.....) +[xopt,fopt,exitflag]= fmincon(.....) +[xopt,fopt,exitflag,output]= fmincon(.....) +[xopt,fopt,exitflag,output,lambda]=fmincon(.....) +[xopt,fopt,exitflag,output,lambda,gradient]=fmincon(.....) +[xopt,fopt,exitflag,output,lambda,gradient,hessian]=fmincon(.....)
a function, representing the objective function of the problem
a vector of doubles, containing the starting values of variables of size (1 X n) or (n X 1) where 'n' is the number of Variables
a matrix of doubles, containing the coefficients of linear inequality constraints of size (m X n) where 'm' is the number of linear inequality constraints
a vector of doubles, related to 'A' and containing the the Right hand side equation of the linear inequality constraints of size (m X 1)
a matrix of doubles, containing the coefficients of linear equality constraints of size (m1 X n) where 'm1' is the number of linear equality constraints
a vector of doubles, related to 'Aeq' and containing the the Right hand side equation of the linear equality constraints of size (m1 X 1)
a vector of doubles, containing the lower bounds of the variables of size (1 X n) or (n X 1) where 'n' is the number of Variables
a vector of doubles, containing the upper bounds of the variables of size (1 X n) or (n X 1) where 'n' is the number of Variables
a function, representing the Non-linear Constraints functions(both Equality and Inequality) of the problem. It is declared in such a way that non-linear inequality constraints are defined first as a single row vector (c), followed by non-linear equality constraints as another single row vector (ceq). Refer Example for definition of Constraint function.
a list, containing the option for user to specify. See below for details.
a vector of doubles, cointating the computed solution of the optimization problem
a scalar of double, containing the the function value at x
a scalar of integer, containing the flag which denotes the reason for termination of algorithm. See below for details.
a structure, containing the information about the optimization. See below for details.
a structure, containing the Lagrange multipliers of lower bound, upper bound and constraints at the optimized point. See below for details.
a vector of doubles, containing the Objective's gradient of the solution.
a matrix of doubles, containing the Lagrangian's hessian of the solution.
Search the minimum of a constrained optimization problem specified by : +Find the minimum of f(x) such that
+The routine calls Ipopt for solving the Constrained Optimization problem, Ipopt is a library written in C++.
+The options allows the user to set various parameters of the Optimization problem. +It should be defined as type "list" and contains the following fields. +
The exitflag allows to know the status of the optimization which is given back by Ipopt. +
For more details on exitflag see the ipopt documentation, go to http://www.coin-or.org/Ipopt/documentation/
+The output data structure contains detailed informations about the optimization process. +It has type "struct" and contains the following fields. +
The lambda data structure contains the Lagrange multipliers at the end +of optimization. In the current version the values are returned only when the the solution is optimal. +It has type "struct" and contains the following fields. +
//Find x in R^2 such that it minimizes: +//f(x)= -x1 -x2/3 +//x0=[0,0] +//constraint-1 (c1): x1 + x2 <= 2 +//constraint-2 (c2): x1 + x2/4 <= 1 +//constraint-3 (c3): x1 - x2 <= 2 +//constraint-4 (c4): -x1/4 - x2 <= 1 +//constraint-5 (c5): -x1 - x2 <= -1 +//constraint-6 (c6): -x1 + x2 <= 2 +//constraint-7 (c7): x1 + x2 = 2 +//Objective function to be minimised +function y=f(x) +y=-x(1)-x(2)/3; +endfunction +//Starting point, linear constraints and variable bounds +x0=[0 , 0]; +A=[1,1 ; 1,1/4 ; 1,-1 ; -1/4,-1 ; -1,-1 ; -1,1]; +b=[2;1;2;1;-1;2]; +Aeq=[1,1]; +beq=[2]; +lb=[]; +ub=[]; +nlc=[]; +//Gradient of objective function +function y=fGrad(x) +y= [-1,-1/3]; +endfunction +//Hessian of lagrangian +function y=lHess(x, obj, lambda) +y= obj*[0,0;0,0] +endfunction +//Options +options=list("GradObj", fGrad, "Hessian", lHess); +//Calling Ipopt +[x,fval,exitflag,output,lambda,grad,hessian] =fmincon(f, x0,A,b,Aeq,beq,lb,ub,nlc,options) | ![]() | ![]() |
//Find x in R^3 such that it minimizes: +//f(x)= x1*x2 + x2*x3 +//x0=[0.1 , 0.1 , 0.1] +//constraint-1 (c1): x1^2 - x2^2 + x3^2 <= 2 +//constraint-2 (c2): x1^2 + x2^2 + x3^2 <= 10 +//Objective function to be minimised +function y=f(x) +y=x(1)*x(2)+x(2)*x(3); +endfunction +//Starting point, linear constraints and variable bounds +x0=[0.1 , 0.1 , 0.1]; +A=[]; +b=[]; +Aeq=[]; +beq=[]; +lb=[]; +ub=[]; +//Nonlinear constraints +function [c, ceq]=nlc(x) +c = [x(1)^2 - x(2)^2 + x(3)^2 - 2 , x(1)^2 + x(2)^2 + x(3)^2 - 10]; +ceq = []; +endfunction +//Gradient of objective function +function y=fGrad(x) +y= [x(2),x(1)+x(3),x(2)]; +endfunction +//Hessian of the Lagrange Function +function y=lHess(x, obj, lambda) +y= obj*[0,1,0;1,0,1;0,1,0] + lambda(1)*[2,0,0;0,-2,0;0,0,2] + lambda(2)*[2,0,0;0,2,0;0,0,2] +endfunction +//Gradient of Non-Linear Constraints +function [cg, ceqg]=cGrad(x) +cg=[2*x(1) , -2*x(2) , 2*x(3) ; 2*x(1) , 2*x(2) , 2*x(3)]; +ceqg=[]; +endfunction +//Options +options=list("MaxIter", [1500], "CpuTime", [500], "GradObj", fGrad, "Hessian", lHess,"GradCon", cGrad); +//Calling Ipopt +[x,fval,exitflag,output] =fmincon(f, x0,A,b,Aeq,beq,lb,ub,nlc,options) | ![]() | ![]() |
//The below problem is an unbounded problem: +//Find x in R^3 such that it minimizes: +//f(x)= -(x1^2 + x2^2 + x3^2) +//x0=[0.1 , 0.1 , 0.1] +// x1 <= 0 +// x2 <= 0 +// x3 <= 0 +//Objective function to be minimised +function y=f(x) +y=-(x(1)^2+x(2)^2+x(3)^2); +endfunction +//Starting point, linear constraints and variable bounds +x0=[0.1 , 0.1 , 0.1]; +A=[]; +b=[]; +Aeq=[]; +beq=[]; +lb=[]; +ub=[0,0,0]; +//Options +options=list("MaxIter", [1500], "CpuTime", [500]); +//Calling Ipopt +[x,fval,exitflag,output,lambda,grad,hessian] =fmincon(f, x0,A,b,Aeq,beq,lb,ub,[],options) | ![]() | ![]() |
//The below problem is an infeasible problem: +//Find x in R^3 such that in minimizes: +//f(x)=x1*x2 + x2*x3 +//x0=[1,1,1] +//constraint-1 (c1): x1^2 <= 1 +//constraint-2 (c2): x1^2 + x2^2 <= 1 +//constraint-3 (c3): x3^2 <= 1 +//constraint-4 (c4): x1^3 = 0.5 +//constraint-5 (c5): x2^2 + x3^2 = 0.75 +// 0 <= x1 <=0.6 +// 0.2 <= x2 <= inf +// -inf <= x3 <= 1 +//Objective function to be minimised +function y=f(x) +y=x(1)*x(2)+x(2)*x(3); +endfunction +//Starting point, linear constraints and variable bounds +x0=[1,1,1]; +A=[]; +b=[]; +Aeq=[]; +beq=[]; +lb=[0 0.2,-%inf]; +ub=[0.6 %inf,1]; +//Nonlinear constraints +function [c, ceq]=nlc(x) +c=[x(1)^2-1,x(1)^2+x(2)^2-1,x(3)^2-1]; +ceq=[x(1)^3-0.5,x(2)^2+x(3)^2-0.75]; +endfunction +//Gradient of objective function +function y=fGrad(x) +y= [x(2),x(1)+x(3),x(2)]; +endfunction +//Hessian of the Lagrange Function +function y=lHess(x, obj, lambda) +y= obj*[0,1,0;1,0,1;0,1,0] + lambda(1)*[2,0,0;0,0,0;0,0,0] + lambda(2)*[2,0,0;0,2,0;0,0,0] +lambda(3)*[0,0,0;0,0,0;0,0,2] + lambda(4)*[6*x(1 ),0,0;0,0,0;0,0,0] + lambda(5)*[0,0,0;0,2,0;0,0,2]; +endfunction +//Gradient of Non-Linear Constraints +function [cg, ceqg]=cGrad(x) +cg = [2*x(1),0,0;2*x(1),2*x(2),0;0,0,2*x(3)]; +ceqg = [3*x(1)^2,0,0;0,2*x(2),2*x(3)]; +endfunction +//Options +options=list("MaxIter", [1500], "CpuTime", [500], "GradObj", fGrad, "Hessian", lHess,"GradCon", cGrad); +//Calling Ipopt +[x,fval,exitflag,output,lambda,grad,hessian] =fmincon(f, x0,A,b,Aeq,beq,lb,ub,nlc,options) | ![]() | ![]() |
Solves a multi-variable unconstrainted optimization problem
xopt = fminunc(f,x0) +xopt = fminunc(f,x0,options) +[xopt,fopt] = fminunc(.....) +[xopt,fopt,exitflag]= fminunc(.....) +[xopt,fopt,exitflag,output]= fminunc(.....) +[xopt,fopt,exitflag,output,gradient]=fminunc(.....) +[xopt,fopt,exitflag,output,gradient,hessian]=fminunc(.....)
a function, representing the objective function of the problem
a vector of doubles, containing the starting of variables.
a list, containing the option for user to specify. See below for details.
a vector of doubles, the computed solution of the optimization problem.
a scalar of double, the function value at x.
a scalar of integer, containing the flag which denotes the reason for termination of algorithm. See below for details.
a structure, containing the information about the optimization. See below for details.
a vector of doubles, containing the the gradient of the solution.
a matrix of doubles, containing the the hessian of the solution.
Search the minimum of an unconstrained optimization problem specified by : +Find the minimum of f(x) such that
+The routine calls Ipopt for solving the Un-constrained Optimization problem, Ipopt is a library written in C++.
+The options allows the user to set various parameters of the Optimization problem. +It should be defined as type "list" and contains the following fields. +
The exitflag allows to know the status of the optimization which is given back by Ipopt. +
For more details on exitflag see the ipopt documentation, go to http://www.coin-or.org/Ipopt/documentation/
+The output data structure contains detailed informations about the optimization process. +It has type "struct" and contains the following fields. +
//Find x in R^2 such that it minimizes the Rosenbrock function +//f = 100*(x2 - x1^2)^2 + (1-x1)^2 +//Objective function to be minimised +function y=f(x) +y= 100*(x(2) - x(1)^2)^2 + (1-x(1))^2; +endfunction +//Starting point +x0=[-1,2]; +//Gradient of objective function +function y=fGrad(x) +y= [-400*x(1)*x(2) + 400*x(1)^3 + 2*x(1)-2, 200*(x(2)-x(1)^2)]; +endfunction +//Hessian of Objective Function +function y=fHess(x) +y= [1200*x(1)^2- 400*x(2) + 2, -400*x(1);-400*x(1), 200 ]; +endfunction +//Options +options=list("MaxIter", [1500], "CpuTime", [500], "Gradient", fGrad, "Hessian", fHess); +//Calling Ipopt +[xopt,fopt,exitflag,output,gradient,hessian]=fminunc(f,x0,options) | ![]() | ![]() |
//The below problem is an unbounded problem: +//Find x in R^2 such that the below function is minimum +//f = - x1^2 - x2^2 +//Objective function to be minimised +function y=f(x) +y= -x(1)^2 - x(2)^2; +endfunction +//Starting point +x0=[2,1]; +//Gradient of objective function +function y=fGrad(x) +y= [-2*x(1),-2*x(2)]; +endfunction +//Hessian of Objective Function +function y=fHess(x) +y= [-2,0;0,-2]; +endfunction +//Options +options=list("MaxIter", [1500], "CpuTime", [500], "Gradient", fGrad, "Hessian", fHess); +//Calling Ipopt +[xopt,fopt,exitflag,output,gradient,hessian]=fminunc(f,x0,options) | ![]() | ![]() |