how to overcome this error Index exceeds array dimensions. Index value 2 exceeds valid range [1-1] of array x.

i am trying to find the skewness value of fft data by setting up the window of width 50 so that it calculates for each window to determine the highest peak(above threshold). I am doing this in Simulink where I directly give input to Matlab function block and getting this error. can you guide me with my code, please.

 %main code
function result_k1= fcn(u)
x=[];
x=[x;u];
result_k1=zeros(100,1);
window_width=50;
for j=1:100
        window_m1=x((j:window_width+(j-1)));  
        window_m11=window_m1(:);
        result_k1(j)=skewness(window_m11);

end %#codegen end

Answer 1

[TADA]

Seems like your input is shorter than your function expects.

You must take the size of u in account when you decide the number of iterations in your loop and the window size, you can have that width 50 as an upper limit, and the index vector j should not exceed the length of u

[srinivasan ravi]

sir,thank you , actually i am trying to implement this function in simulink now i increased the size of number of iteration to 170 it is running but i am getting empty result(NaN). when I load the data into workspace and process that function i am getting the output.

 % code
function result_k1= fcn(u)
result_k1=zeros(200,1);
window_width=50;
for j=1:170
        window_m1=u((j:window_width+(j-1)));  
        window_m11=window_m1(:);
       result_k1(j)=skewness(window_m11);

Answer 2

[Anurag Kammari]

function [Sa,Sb,Sc,Tp1] = control(T_ref,sflux_ref,wm,i_meas,Ts, Lm, Lr, Ls, Rs, kr, t_sigma, tr, r_sigma, v, states, p, lambda)

persistent x_opt Fs

if isempty(x_opt),x_opt = 1;end

if isempty(Fs),Fs = 0+0i*1;end

Fs = Fs+Ts*(v(x_opt)-Rs*i_meas);

Fr = Lr/Lm*Fs+i_meas*(Lm-Lr*Ls/Lm);

g = zeros(1,19);

for i = 1:19

v_01 = v(i);

Fsp1 = Fs+Ts*v_01-Rs*Ts*i_meas;

Isp1 = (1+Ts/t_sigma)*i_meas+Ts/(t_sigma+Ts)*...

(1/r_sigma*((kr/tr-kr*1i*wm)*Fr+v_01));

Tp1 = 3/2*p*imag(conj(Fsp1)*Isp1);

g(i)=abs(T_ref-Tp1)+lambda*abs(sflux_ref-abs(Fsp1));

end

[~,x_opt] = min(g);

Sa = states(x_opt,1);

Sb = states(x_opt,2);

Sc = states(x_opt,3);

Caused by: Index exceeds array dimensions. Index value 3 exceeds valid range [1-1] for array 'states'. Error in 'PTCL3/Controller' (line 17) Sa = states(x_opt,1);