If loop with character and two conditions

Hello,

I am trying to create a loop, where I have ran two hypothesis tests, (ADF and KPSS test). And I want matlab to return the concltion in the command window, there is three outcomes, based on the conclution from the test.

This is what I got so far, but the problem is that in the case where the variable is not equal matlab returns: "Arrays have incompatible sizes for this operation."...

% Stationarity conclution loop
if t_adf_fdiff.reject == t_kpss_fdiff.reject
    disp('Inconclusive test');
    if isequal(t_adf_fdiff.reject, 'reject H0') &&...
            isequal(t_kpss_fdiff.reject, 'do not reject H0')
        disp(['The time series does not containt a unit root, and are '...
            'stationary']);
    if isequal(t_adf_fdiff.reject, 'do not reject H0') &&...
            isequal(t_kpss_fdiff.reject, 'reject H0')
        disp(['The time series containt a unit root, and are not'...
            'stationary']);
    end
    end
end

Answer 1

[J Chen]

Use

strcmp(t_adf_fdiff.reject,t_kpss_fdiff.reject)

insteafd of t_adf_fdiff.reject == t_kpss_fdiff.reject. The two if statements under the top if statement are meaningless since t_adf_fdiff.reject will be always equal to t_kpss_fdiff.reject.

[Andreas Bull]

Thank you! This resolves the error, but my next problem is that the loop does not display anything in the case where they are unequal..

Changed to:

if strcmp(t_adf.reject,t_kpss_level.reject)
    disp('Inconclusive test');
    if isequal(t_adf.reject, 'reject H0') &&...
            isequal(t_kpss_level.reject, 'do not reject H0')
        disp(['The time series does not containt a unit root, and are '...
            'stationary']);
    if isequal(t_adf.reject, 'do not reject H0') &&...
            isequal(t_kpss_level.reject, 'reject H0')
        disp(['The time series containt a unit root, and are not'...
            'stationary']);
    end
    end
end

[J Chen]

Your script will not display anything as it is since the following two if statements will never be true:

if isequal(t_adf.reject, 'reject H0') &&...
            isequal(t_kpss_level.reject, 'do not reject H0')
    
if isequal(t_adf.reject, 'do not reject H0') &&...
            isequal(t_kpss_level.reject, 'reject H0')

[Andreas Bull]

Isn´t for example the first example...

if isequal(t_adf.reject, 'reject H0') &&...
            isequal(t_kpss_level.reject, 'do not reject H0')
    

The same as saying: "if t_adf = reject and t_kpss = do not reject"

In that case this statement can be true.

[J Chen]

The strcmp(t_adf.reject,t_kpss_level.reject) will not be true in the first place in this case.