Coder. Error due mismatched varying sizes

Good evening. I made the function NEOEKF and then tried to convert to C++ with coder, but I got the following warning:

57 Size mismatch (size [:? x 1] ~= size [4 x 1]). Mismatched varying and fixed sizes indicate a probable run-time error. If this diagnostic is incorrect, use indexing to explicitly make the varying size fixed.

Does any one can support me how to fix it? Refer to line 57

Thank you in advance.

regards Willy

function [DIST,VEL,RB] = NEOEKF(dT,T2)
Mo = 030;
dT = 20;
T2 = 360;
Xs = [0 0 4 0];
yseg = 2025.371/3600;
F = [1 0 0 0;0 1 0 0;dT 0 1 0 ;0 dT 0 1];
dd= 100;
dve= 15;
P = [dd^2 0 0 0;
     0 dd^2 0 0;
     0 0 dve^2 0;
     0 0 0 dve^2];
v = 0.5;
R = pi/180*v^2;
X = [];
X = [15000*sin(Mo*pi/180) 15000*cos(Mo*pi/180) 0 0]';
I=eye(4);
Q = 15*[0.5*dT^3 0 0.25*dT^4 0;0 0.5*dT^3 0 0.25*dT^4;...
    dT^2 0 0.5*dT^3 0;0 dT^2 0 0.5*dT^3];
DIST = size(T2);
VEL = size(T2);
RB = size(T2);
z = 30:0.4:34;
for k = 1:1:10
    X(:,k+1) = F*X(:,k);
P_ = F*P*F'+ Q;
sx = X(1,k);
sy = X(2,k);
h = atan2(sx,sy);
if h<0
    h = h + 2*pi;
elseif h>2*pi
    h = h - 2*pi;
end    
H = [sy/(sx^2 + sy^2) -sx/(sx^2 + sy^2) 0 0];
g = [cos(z(k))/(X(1)*sin(z(k))+ X(2,k+1)*cos(z(k))) -sin(z(k))/(X(1,k+1)*...
    sin(z(k))+ X(2,k+1)*cos(z(k))) 0 0];
S = H*P_*H'+ R;
G = P_*H'/S;
X(:,k+1) = X(:,k+1)+ G*(z(k) - h); % Line 57
P =(I - G*g)*P_*(I - G*g)' + G*R*G';
DIST(k+1) = sqrt(X(1,k+1).^2 + X(2,k+1).^2);
VEL(k+1) = sqrt((X(3,k+1) + Xs(3)).^2 + (X(4,k+1) + Xs(4)).^2)/yseg;
RB(k+1) = atan2(X(3,k+1)+ Xs(3),X(4,k+1) + Xs(4))*180/pi;
RB(k+1) = round(RB(k+1));
if RB(k+1)<0
    RB(k+1) = RB(k+1) + 360;
elseif    RB(k+1) > 360;
    RB(k+1) = RB(k+1) - 360;
end
X(:,k) = [X(:,k)];
end

[Image Analyst]

Guillermo, to get your code to show up on separate lines, you can highlight the code and click the {}Code icon to make it look like code. That is far better than double spacing your code. Give it a try. Edit, remove blank lines, highlight, then click {}Code and Save.

[Guillermo Soriano]

Good morning. I was not familiar with that tip. Initially appears all in one line, therefore I corrected with double line, but with your indication, look much better. Unfortunately the line number is not shown. Thank you very much for your support. Regards Guillermo

Answer 1

[Walter Roberson]

Your z values are not integral, so z(k) is not integral, and h is not integral, so z(k)-h is not integral. But you have G() at that expression. G appears to be an array rather than a function, so I do not understand why it does not complain about indexing at a non-integral value ?

[Walter Roberson]

Oh, you tried formatting as bold, and then you got messed up on the fact that a multiplication already existed on the line and was considered to end the bold instead of showing the multiplication.

In that case, is there reason to expect that G will be a scalar ?

[Guillermo Soriano]

Good morning Walter. Thank you for your assistance. This an algorithm wich pretend to solve the parameters of a target with only bearings for tracking purpose using the well known Extended Kalman Filter. Therefore the z is the bearing as input for each iteration. But there was a warning that hte function "INPUT" can not be coded from matlab to C++ and therefore I modified to be as a integer. But the error is on line 57 refer to array X(:,k+1) = X(:,k+1)+ G*(z(k) - h); When I run the algorithm on Matlab, it works. But passing to C++, comes the error and can not be coded. Regards Guillermo

[Walter Roberson]

Do no extend your X array at run-time. Initialize it to be its final size as the very first time you assign to X, using zeros().