How can I solve this problem?

I got a loop that reads the messages and gets the information of these messages, while looping it stops due to a common error. How can I solve it. My code is:

 for i=1:1:P
    seq1 = AIS2(i);
    linia=convertStringsToChars(seq1);
    if linia(13)=='A' && linia(15)=='1'
        
        sequencia = ais_to_bit(linia(15:44));
    
        s_longitud=sequencia(62:89);
        longitud = bin2dec(num2str(s_longitud))/600000; lon1 = [lon1, longitud];
        s_latitud=sequencia(90:116);
        latitud = bin2dec(num2str(s_latitud))/600000; lat1 = [lat1, latitud];   
        pos_lat = 1:numel(lat1); value_lat = lat1(lat1>50); index1 = pos_lat(lat1>50);
        lat1(index1) = [];lon1(index1) = [];
        pos_lon = 1:numel(lon1); value_lon = lon1(lon1>3); index2 = pos_lon(lon1>3);
        lat1(index2) = []; lon1(index2) = []; 
    end
 end

and the error I get is:

 Index exceeds the number of array elements. Index must not exceed 35.

Error in NewCode (line 37)
        sequencia = ais_to_bit(linia(15:44));

I understand the problem as I have read about it in other posts, how could I program it as if it happens with a message ust delete this message and continue with the loop?

Answer 1

[Voss]

This will capture any errors that happen in that if block, display the error message to the command line, and continue with the loop.

for i=1:1:P
    
    seq1 = AIS2(i);
    linia=convertStringsToChars(seq1);
    
    try
        
        if linia(13)=='A' && linia(15)=='1'
            
            sequencia = ais_to_bit(linia(15:44));
            
            s_longitud=sequencia(62:89);
            longitud = bin2dec(num2str(s_longitud))/600000; lon1 = [lon1, longitud];
            s_latitud=sequencia(90:116);
            latitud = bin2dec(num2str(s_latitud))/600000; lat1 = [lat1, latitud];   
            pos_lat = 1:numel(lat1); value_lat = lat1(lat1>50); index1 = pos_lat(lat1>50);
            lat1(index1) = [];lon1(index1) = [];
            pos_lon = 1:numel(lon1); value_lon = lon1(lon1>3); index2 = pos_lon(lon1>3);
            lat1(index2) = []; lon1(index2) = []; 
            
        end
        
    catch ME
        
        disp(ME.message);
        continue
        
    end
    
    % Note: 'continue' above is only necessary if you have more code down
    % here that you want to skip when there is an error above.
    
end

Or you can just capture errors that happen on that one line that gives the error now (and display it and continue as above):

for i=1:1:P
    
    seq1 = AIS2(i);
    linia=convertStringsToChars(seq1);
    
    if linia(13)=='A' && linia(15)=='1'
            
        try
            sequencia = ais_to_bit(linia(15:44));
        catch ME
            disp(ME.message);
            continue
        end
        
        s_longitud=sequencia(62:89);
        longitud = bin2dec(num2str(s_longitud))/600000; lon1 = [lon1, longitud];
        s_latitud=sequencia(90:116);
        latitud = bin2dec(num2str(s_latitud))/600000; lat1 = [lat1, latitud];   
        pos_lat = 1:numel(lat1); value_lat = lat1(lat1>50); index1 = pos_lat(lat1>50);
        lat1(index1) = [];lon1(index1) = [];
        pos_lon = 1:numel(lon1); value_lon = lon1(lon1>3); index2 = pos_lon(lon1>3);
        lat1(index2) = []; lon1(index2) = []; 
        
    end
    
end