failure in user-supplied fitness function evaluation. GA cannot continue. problem based

hi im using problem based format to do optimization, when im using fmincon it doest have a problem however it fall to local minimum therefore, i try using GA but somehow it have error as follow;

Error using interp1

Input coordinates must be real.

Error in ha>objectiveFcn (line 63)

data(i,16)=interp1(RS(1,:),RS(2,:),data(i,12))/data(i,15);

Error in generatedObjective (line 42)

....

Error in ha (line 45)

[solution,objectiveValue,reasonSolverStopped] = solve(problem,initialPoint,Solver="ga",Options=opts);

Caused by:

Failure in user-supplied fitness function evaluation. GA cannot continue.

below is the coding....

clear;
clc;

%data input
data=readmatrix('sortout data.xlsx');
%column 1 = no PGA
%column 2 = PGA
%column 3 = M(kg)
%column 4 = Friction Damping (N)
%column 5 = sloping angle (radian)
%column 6 = arc radius (m)
%column 7 = arc range (m)
%column 8 = NLTH displacement
%column 9= NLTH acceleration
responsespectra=readmatrix('far field response spectra.xlsx');
dampingfactor=[2 0.8;5 1;10 1.2;20 1.5;30 1.7;40 1.9;50 2].';

% Create optimization variables
A3 = optimvar("A",LowerBound=-50,UpperBound=50);
B3 = optimvar("B",LowerBound=-50,UpperBound=50);
C3 = optimvar("C",LowerBound=-50,UpperBound=50);
D3 = optimvar("D",LowerBound=-50,UpperBound=50);
E3 = optimvar("E",LowerBound=-50,UpperBound=50);
F3 = optimvar("F",LowerBound=-50,UpperBound=50);

% Set initial starting point for the solver
initialPoint.A = 1;
initialPoint.B = 1;
initialPoint.C = 1;
initialPoint.D = 1;
initialPoint.E = 1;
initialPoint.F = 1;

% Create problem
problem = optimproblem;

% Define problem objective
expr=fcn2optimexpr(@objectiveFcn,A3,B3,C3,D3,E3,F3,data,responsespectra, ...
    dampingfactor);
problem.Objective = expr;

% Define problem constraints

% Solve problem
opts=optimoptions("ga",'UseParallel',true);
[solution,objectiveValue,reasonSolverStopped] = solve(problem,initialPoint, ...
    Solver="ga",Options=opts);

%function
function objective = objectiveFcn(A,B,C,D,E,F,data,responsespectra,dampingfactor)
data(:,10)=A+B*data(:,5)+C*(data(:,4)./data(:,3)); %optimization Keq
data(:,11)=(data(:,4)+data(:,3)*9.81.*data(:,7)/2./data(:,6))./data(:,8).*data(:,10);%Keq
data(:,12)=2*pi*sqrt(data(:,3)./data(:,11));%Teq
data(:,13)=D+E*data(:,5)+F*(data(:,4)./data(:,3)); %optimization KSIeq
data(:,14)=2*data(:,4)/pi./data(:,11)./data(:,8).*data(:,13)*100; %Ksi
for i=1:length(data)
if data(i,14)<=2
  data(i,15)=0.8;
elseif data(i,14)>=50
  data(i,15)=2;
else 
  data(i,15)=interp1(dampingfactor(1,:),dampingfactor(2,:),data(i,14));
end
RS=responsespectra(:,[1 1+data(i,1)]).';
data(i,16)=interp1(RS(1,:),RS(2,:),data(i,12))/data(i,15);
end
objective=mean((data(:,16)-data(:,8))./data(:,8))*100;
end

Answer 1

[Matt J]

The error message is complaining that RS(1,:),RS(2,:), or data(i,12) do not contain real values. You should check.