Plot time vector in x axis

I have a time vector: time = 62949,62950,62951,62952,62953,62954... Where the first one/two digits represent the hour, the third/fourth digits represent the minute and the last two digits represent the seconds. Every second I have a new measurement point.

The problem is, when I plot my data, matlab interpolates between the minute and the hour transition, e.g. from 65959 to 70000. I tried to use datenum and datetick, but that did not work well. See the picture of the plot.

   timeStr = arrayfun(@num2str, time, 'UniformOutput', false); 
   time = datenum(timeOUTStr,'hhmmss'); 
   plot(time(indexOUT1:indexOUT2), GPS_Data_Raw{5,2}(indexOUT1:indexOUT2,i),'Color',[colors(j,:)],'DisplayName',name,'LineWidth',1.5);
   xlim([timeOUT(indexOUT1)-100 timeOUT(indexOUT2)+100]);
   ylim([0 60]);
   set(gca,'XTick',timeOUT(indexOUT1)-100:1:timeOUT(indexOUT2)+100);
   set(gca, 'XTickLabel', num2str(get(gca,'XTick')','%d'))
   set(gca,'YTick',0:5:60);
   datetick('x', 'HH:MM:SS');

This code leads to this:

All I want is that matlab only plots the data in my vectors and does not interpolate between "missing" data. Maybe I did something wrong while using datenum and datetick or there is another possibility forcing the plot to show only the data given in the x vector.

Thank you in advance for help.

Answer 1

[Mischa Kim]

Chani, you can simply just plot markers, e.g., note the 'b*' in

 plot(x,y,'b*');

In this case the marker is a blue star.

[Chani]

I figured out how it works with datenum, I extracted the hour, minutes and seconds from my time vector and after that used the following code:

 time = datenum(repmat(2014,size(hourOUT,1),1),repmat(03,size(hourOUT,1),1),repmat(01,size(hourOUT,1),1),hourOUT,minuteOUT,secondOUT);

plot(time(indexOUT1:indexOUT2), GPS_Data_Raw{5,2}(indexOUT1:indexOUT2,i),'Color',[colors(j,:)],'DisplayName',name,'LineWidth',1.5); ylim([0 60]); grid minor; set(gca,'YTick',0:5:60); datetick('x', 'HH:MM:SS');

Now it looks like this:

The next question is, how I can increase the x Axis resolution in such a way that i see every single minute or so.

Any ideas? :)

[Mischa Kim]

You need to set axis ticks and tick labels. Check out

 t     = 0:100;
 y     = rand(1,length(t));    % just some made-up data
 t_int = 10;                   % tick intervals
 tt    = t(rem(t,t_int)==0);   % find tick locations
 ttlab = num2cell(tt);         % and generate tick labels
 plot(t,y)
 set(gca,'XTick', tt, 'XTickLabel', ttlab)

and change t_int. For your problem t_int would be determined by your minute-spacing requirement.