how my code get the bit modification?

this stops on 90,180,270,360 now i want certain changes to stops at 45,115,225,315 what changes are required?

%load excel data
trials_1 = xlsread('Block1_3');

%general
subject = 'final';      % enter subject code
IBF = 20;               % individual beta frequency
protlength = 750;       % in seconds length of final output
ramptime = 10;          % in seconds length of ramp time
fsample = 10000;        % sampling rate of data
saveloc = '/Users/tinahocher/Desktop/MATLAB_EEGLAB_DATA /Phase_stop/';

% time vector
t = [1/fsample:1/fsample:protlength];

%---------------------------
% create sine wave
beta{1} = sin(IBF*2*pi*[1/fsample:1/fsample:protlength]);

%create mat file
stimuli = zeros(5,protlength.*fsample);

%add beta wave
for it = 1:length(beta)
    stimuli(3,:) = beta{it};
    % ramp up
    in = 1:ramptime*fsample;
    stimuli(3,in) = beta{it}(in).*linspace(0,1, length(in));
end

save([saveloc 'try_stim_' subject], 'stimuli');

%add trigger at start of each trial
x = trials_1;
for i = 1:length(x)
    start_trial(i) = x(i,4);
    start_trial(i) = ((start_trial(i))*fsample) +(ramptime*fsample);
end
for j = 1:length(start_trial)
    stimuli(5,round(start_trial(j)-5):round(start_trial(j)+5)) = 16;
end

%add trigger at eacht stop
for i = 1:length(x)
    stop_time(i) = x(i,2);
    stop_time(i) = ((stop_time(i))*fsample);
    if ~isnan(stop_time(i))
        stop_trigger(i) = stop_time(i) + start_trial(i);
    else stop_trigger(i) = NaN;
    end
end
stop_trigger_final = stop_trigger(~isnan(stop_trigger));

% %---------------------------------
% %turn off just for testing purpose
% for j = 1:length(stop_trigger_final)
%     stimuli(5,round(stop_trigger_final(j))) = 8;
% end
% %---------------------------------

stop_phase = x(~isnan(stop_trigger),3);
for j = 1:length(stop_trigger_final)
    beta_stop(j) = stimuli(3,round(stop_trigger_final(j)));
    if stop_phase(j) == 1 %90deg
        loc_phase = stimuli(3,[round(stop_trigger_final(j)-250):round(stop_trigger_final(j)+250)])==1;
        loc_phase = find(loc_phase==1);
        sample_loc_phase(j) = (round(stop_trigger_final(j)-[250-loc_phase]));
       
        
        % 2 = zero coming from positive  going into negative
    elseif stop_phase(j) == 2 %180deg
       data = stimuli(3,[round(stop_trigger_final(j)-250):round(stop_trigger_final(j)+250)]);
        zerocross = find(diff(sign(data)));
        if length(zerocross)>1
           for z = 1:length(zerocross)
               if data(zerocross(z)+1) < 0
                  sample_loc_phase(j) = (round(stop_trigger_final(j)-[250-zerocross(z)]));
               end
           end
        else sample_loc_phase(j) = (round(stop_trigger_final(j)-[250-zerocross]));
        end
        
    elseif stop_phase(j) == 3 %270deg
        loc_phase = stimuli(3,[round(stop_trigger_final(j)-250):round(stop_trigger_final(j)+250)])==-1;
        loc_phase = find(loc_phase==1);
         sample_loc_phase(j) = (round(stop_trigger_final(j)-[250-loc_phase]));

        
        % 4 = zero coming from negative  going into positive
    elseif stop_phase(j) == 4 %360deg
        data = stimuli(3,[round(stop_trigger_final(j)-250):round(stop_trigger_final(j)+250)]);
        zerocross = find(diff(sign(data)));
        if length(zerocross)>1
           for z = 1:length(zerocross)
               if data(zerocross(z)+1) > 0
                  sample_loc_phase(j) = (round(stop_trigger_final(j)-[250-zerocross(z)]));
               end
           end
        else sample_loc_phase(j) = (round(stop_trigger_final(j)-[250-zerocross]));
        end
        
    else sample_loc_phase(j) = 0;
    end
end

for j = 1:length(sample_loc_phase)
    stimuli(5,round(sample_loc_phase(j)-5):round(sample_loc_phase(j)+5)) = 32;
end

save([saveloc 'stop_phase_2_4_' subject], 'stimuli');

%plotting
for j = 1:length(sample_loc_phase)
figure
plot(t(sample_loc_phase(j)-8000:sample_loc_phase(j)+1000), stimuli(3,sample_loc_phase(j)-8000:sample_loc_phase(j)+1000))
hold on
plot(t(sample_loc_phase(j)-8000:sample_loc_phase(j)+1000), stimuli(5,sample_loc_phase(j)-8000:sample_loc_phase(j)+1000)/10)
end

[Geoff Hayes]

@Muhammad - in your code, you have

    if stop_phase(j) == 1 %90deg
        % ...
        % 2 = zero coming from positive  going into negative
    elseif stop_phase(j) == 2 %180deg
        % ...
    elseif stop_phase(j) == 3 %270deg
        % ...
        % 4 = zero coming from negative  going into positive
    elseif stop_phase(j) == 4 %360deg

If 1, 2, 3 and 4 correspond to 90, 180, 270, and 360 degrees, then what should correspond to 45,115,225,315?