i want to know what is meant by double here pl answer

Error using ga (line 342)
Undefined function 'constraints' for input arguments of type 'double'.

Error in main1 (line 11)
[x, fbest, exitflag] = ga(ObjectiveFunction, nvars, [], [], [], [],LB, UB,
ConstraintFunction,1:168, opts);

Caused by:
    Failure in initial user-supplied nonlinear constraint function evaluation.

while my constraints function is

 function [c, ceq]=constraints(x)

Answer 1

[mariam mughees]

whe i run my main file of GA it gives this error

Answer 2

[Walter Roberson]

In your code calling ga, you show ConstraintFunction . Did you code that as

ConstraintFunction = 'constraints';

and is your code

function [c, ceq]=constraints(x)

in the same file as your main1 ?

In that combination of circumstances, MATLAB would not be able to find the constraints function. When you specify a function name by a string, then MATLAB evaluates the string in the context of the base workspace, and the base workspace can only find named functions which have their own .m file, not functions that are in the same file as the calling code.

The way to fix this would be to change to

ConstraintFunction = @constraints;

[mariam mughees]

i have defined it in same way already ConstraintFunction = @constraints;

[Walter Roberson]

Is your constraints function in the same file as main1.m or is it in a separate file constraints.m ? Please show your code.