gone gone gone deleted

gone gone gone gone

[Stephen23]

Original question by Sarah Garcon:

https://web.archive.org/web/20201203052119/https://webcache.googleusercontent.com/search?q=cache%3AA3GFOHEESqIJ%3Ahttps%3A%2F%2Fwww.mathworks.com%2Fmatlabcentral%2Fanswers%2F674748-fmincon-error-failure-in-initial-objective-function-evaluation-fmincon-cannot-continue

FMINCON error: Failure in initial objective function evaluation. FMINCON cannot continue.

I am trying to find the coordinates of the center of rotation as seen by the coordinate systems of the two sensors using a file (data1.mat) that includes the coordinates of the positions (rM3 and rM4, 3xN vectors, with N=1001 measurements for the components of x, y, and z of the sensor position vector) and orientations (R3 and R4, 3x3xN vectors, including the rotation matrices describing the orientation of the sensor frame as seen from the world frame) of two sensors placed on two rigid bodies subject to a rotation about a single point.

Below if what I tired and the error that i keep on getting

main code

function y = normcalc(x,rM3, R3, rM4, R4)
    rs1 = rM3 + R3*x(1:3);
    rs2 = rM4 + R4*x(4:6);
    y = sum(norm(rs1-rs2));
end

from command window

>> load('data1.mat')
>> fun = @normcalc;
>> x0 = [0,0,0,0,0];
>> A = [];
>> b = [];
>> x = fmincon(fun,x0,A,b)
Not enough input arguments.
Error in normcalc (line 2)
    rs1 = rM3 + R3*x(1:3);
Error in fmincon (line 546)
      initVals.f = feval(funfcn{3},X,varargin{:});
Caused by:
    Failure in initial objective function evaluation. FMINCON cannot continue.

Answer 1

[Star Strider]

Try this instead:

x = fmincon(@(x)fun(x,rM3, R3, rM4, R4),x0,A,b)

I cannot run your code since I don’t have the file. I assume it otherwise works, and the calculations are correct.

[Star Strider]

That operation is never going to work.

First,

R3*x(1:3)

needs to be replaced by:

bsxfun(@mtimes,R3,x(1:3))

that if ‘x’ is a row vector then produces a (3x3x1001) result because that is the size of ‘R3’, however if ‘x’ is a column vector, regardless of the order, the dimensions are incompatible and there is no result.

In any event, since ‘rM3’ is a (3x1001) matrix, those results are incompatible so the addition operation will fail.

You need to reconfigure whatever it is that you’re doing.

I will delete my Answer in a few hours.

[Stephen23]

Original comment by Sarah Garcon:

https://web.archive.org/web/20201203052155/https://webcache.googleusercontent.com/search?q=cache%3AlWxIuyec2dcJ%3Ahttps%3A%2F%2Fjp.mathworks.com%2Fmatlabcentral%2Fanswers%2F674748-fmincon-error-failure-in-initial-objective-function-evaluation-fmincon-cannot-continue

Array dimensions must match for binary array op.

Error in normcalc (line 2)

rs1 = rM3 + R3.*x(1:3);

Error in @(x)fun(x,rM3,R3,rM4,R4)

Error in fmincon (line 546)

initVals.f = feval(funfcn{3},X,varargin{:});

Caused by:

Failure in initial objective function evaluation. FMINCON cannot continue.

I have also attached the file