Why properties of class is not initialized ?

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Hafiz Luqman
Hafiz Luqman on 7 Dec 2018
Answered: Robert U on 7 Dec 2018
classdef EKF
properties
is_initialized_ = false;
previous_timestamp_ = 0;
H_jacobian = zeros(3, 4);
%measurement covariance matrix - laser
R_laser_ = [0.0225, 0;
0, 0.0225];
noise_ax;
noise_ay;
end
methods
function obj = EKF(obj)
obj.noise_ax = 5;
obj.H_laser_ = [1, 0, 0, 0;
0, 1, 0, 0];
end
end
end
When I create an object of this class, I just get back. WHy these properties are not initialized ?
> obj = EKF
EKF with properties:
Value: []

Answers (1)

Robert U
Robert U on 7 Dec 2018
Hi Hafiz Luqman
The class definition you posted is errornous. The property "H_laser_" is not defined. So the constructor returns error:
test = EKF
No public property H_laser_ exists for class EKF.
Error in EKF (line 19)
obj.H_laser_ = [1, 0, 0, 0;
While programming oop and evaluating changes of code it happens that earlier class definitions remain in memory. You could try to use
clear all
The corrected class definition (without questioning the sense) is working without troubles and as expected:
classdef EKF
properties
is_initialized_ = false;
previous_timestamp_ = 0;
H_jacobian = zeros(3, 4);
%measurement covariance matrix - laser
R_laser_ = [0.0225, 0;
0, 0.0225];
noise_ax;
noise_ay;
H_laser_;
end
methods
function obj = EKF(~)
obj.noise_ax = 5;
obj.H_laser_ = [1, 0, 0, 0;
0, 1, 0, 0];
end
end
end
Kind regards,
Robert

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