Index in position 2 exceeds array bounds

Hi, I have this script

%%
% DEFINIZIONE PARAMETRI DINAMICI   

%DEFINIZIONE vettore frequenze
F_plot=400;               %Frequenza limite dell'analisi
df=0.1;                  
f=[0:df:F_plot];
w=2*pi*f;



%%

% COSTRUZIONE SS  

csi=0.0024;  %  smorzamento percentuale -- 0.05 è il valore nella flexsspf


FREQ_equi=load(['freq_prop.txt']);

pfdx_equi=load(['pffe.txt']);


%modi=[1:length(FREQ_equi)]';

%gamma_equi=pfdx_equi(:,2);    % matrice dei fattori di partecipazione modale 

save('PF1_equi.dat','pfdx_equi', '-ascii')     % | modo | PF1  | PF2  | ... |  PFr |
save('FREQ1_equi.dat','FREQ_equi', '-ascii')    % | modo | freq

type=1; % 1 se spostamento ( q ), 2 se accelerazione ( q** )
        

[Aq,Bq,Cq,Dq]=flexsspf('','PF1_equi.dat','freq_prop.txt',csi,type);  
sysansq_equi=ss(Aq,Bq,Cq,Dq);


%%

% vado a plottare il modulo della funzione di risposta in frequenza 

[mags,phases]=bode(sysansq_equi,w);   

[output,input,frequencies]=size(mags); 

figure (1)
semilogy(f,squeeze(mags(:,1,:)),'linewidth',1)
hold on
grid on
title('Mag FRFs uscite/ingressi')
xlabel('Frequency [Hz]')
ylabel('Mag FRF [Disp Unit/Force Unit]')
legend('q1','q2','q3','q4','q5','q6','q7','q8','q9','q10');

and this error is occurred

In untitled34 (line 43)

Index in position 2 exceeds array bounds.

Error in untitled34 (line 56)

semilogy(f,squeeze(mags(:,1,:)),'linewidth',1)

Can i solve this problem?

[Walter Roberson]

check if mags is empty

[Federico Paolucci]

mags

mags =

10×0×4001 empty double array

[Walter Roberson]

yes that is empty.

[Walter Roberson]

is your flexsspf still the code from https://www.mathworks.com/matlabcentral/answers/1769315-the-a-and-b-matrices-must-have-the-same-number-of-rows ? that code ignores several of its inputs

[Federico Paolucci]

More or less it is the same, the only differences are these: in flexsspf I inserted the frequency file as .txt instead of .dat, because otherwise it didn't work. Then I removed the number of modes from the input files and then commented "modi" because I don't need it. The fact is that the flexsspf function should work even without the first input which is empty in the script, because in theory only frequencies and pf (participation factors) should suffice

[Walter Roberson]

please show the new code