PACKAGE OPTIM - fmincon

[steph]

I have the following function works in Matlab, but not in Octave, the error message is

 

error: lbound: wrong dimensions

error: called from

    __apply_param_config_vectors__ at line 37 column 11

    fmincon at line 311 column 5

 

I have tried  transpose of lower bound, i.e.   x0_lb = [-100,0]’ but then same message, except that upper bound now has wrong dimension, then I took transpose of X0_ub and message reverts back to lower bound has wrong dimension.

 

Any assistance will be appreciated.

 

FUNCTION is

 

function [ k1, k2, RMSE ] = fn_FIT_WLF( aT_measured, Tref, T )

% WLF Shift Function

%   Note: temperatures are in K, and aT is input

%   In this function the constants C1 and C2 in WLF function

%   is calculated that minimize the error in aT

%   at temperature (T) for reference temperature (Tref)

 

% calculate the RMSE

fun_WLF = @(x)fn_WLF_RMSE( x, aT_measured, Tref, T );

x0_lb = [-100,0];  % lower bound of C1, C2

x0_ub = [200,200]; % upper bound of C1, C2

x0 = [-15,80];     % initial estimate of C1, C2

 

[x, RMSE] =...

    fmincon(fun_WLF, x0, [], [], [], [], x0_lb, x0_ub);

   

k1 = x(1);

k2 = x(2);

 

end

 

Steph Bredenhann PrEng, PrCPM