How to set the axis to display hours?

How can I make the datetick count from 00:00 to 23:59. This below is dispalying 00:00 for every hour.

d= datetime(start_date):1/24:datetime(end_date)+1;
hours=hour(d);
scatter(hours,rand(size(d)));
t=datenum(d);
ax=gca;
ax.XTick=1:24;
datetick(ax,'x','HH:MM','keeplimits','keepticks')

Answer 1

[Guillaume]

The XTick values need to be date number for datetick to work, so maybe:

ax.XTick = ceil(ax.XLim(1)):1/24:floor(ax.XLim(2));
datetick(ax,'x','HH:MM','keeplimits','keepticks');

[ccs]

Thanks Guillaume. Is this line not converting to date numbers >>t=datenum(d);?

The lines you provided display a black thick line on the x axis.

[Guillaume]

Yes, it does, but you're not using it afterward. So, yes another option would be:

t = datenum(d);
scatter(t, rand(size(d)));
datetick(gca,'x','HH:MM','keeplimits','keepticks')

But you may have way more than 24 ticks depending on the number of hours between start_date and end_date. Moreover, if start_time does not fall exactly on the hour, your ticks won't either.

My solution produces a tick exactly every hour, for each hour. If you have lots of hours then they all overlap and you get a sort of thick black line. I wasn't sure you wanted a tick every hour, or just 24 ticks. If just 24 ticks:

ax.XTick = linspace(ceil(ax.XLim(1)), floor(ax.XLim(1)), 24);

edit: typo

[ccs]

Thanks again Guillaume. Yes, I want just 24 ticks, from 00:00 to 23:59 so that i can be able to use it to plot measured data for the whole day (and for each day) for a given range of days. the last line gives this error:

>>ax.XTick = linspace(ceil(ax.XLim(1)), floor(ax.XLim(1), 24)); Error using floor Too many input arguments.

[Guillaume]

Yes, there was a typo, missing a bracket which you added in the wrong place. I've corrected my answer

[ccs]

>> d= datetime(start_date):1/24:datetime(end_date)+1;

>> hours=hour(d);

>> t=datenum(d);

>> scatter(hours,rand(size(d)));

>> ax=gca;

>> ax.XMinorTick='on';

>> ax.XTick = linspace(ceil(ax.XLim(1)), floor(ax.XLim(1)), 24);

While setting the 'XTick' property of Axes: Value must be a vector of type single or double whose values increase

Now it says the vector values aren't increasing. Sorry I can figure this out.