MATLAB: How to display XTicks from the command line

axishandle graphicsMATLABplot

INTRO: Hi I plot arbitrary data against date ticks for hours of the day as below:
%Get traffic count data
load count.dat
% Create arrays for an arbitrary date, here April 18, 1995
n = length(count);
year = 1990 * ones(1,n);
month = 4 * ones(1,n);
day = 18 * ones(1,n);
% Create arrays for each of 24 hours;
hour = 1:n;
minutes = zeros(1,n);
% Get the datenums for the data (only hours change)
xdate = datenum(year,month,day,hour,minutes,minutes);
% Plot the traffic data against datenums
plot(xdate,count)
% Update the graph's x-axis with date ticks
datetick('x','HHPM')
GOAL: I want to display the XTicks and modified the following lines:
h=subplot(1,1,1);
plot(xdate,count);
set(h,'XTick',xdate)
datetick(h,'x','HH','keepticks')
QUESTION: Why do I need to use subplot to display the XTick? I have also the version suggested by Walter:
h = plot(xdate,count);
haxis = ancestor(h, 'axes');
set(haxis, 'XTick', xdate);
datetick(haxis, 'x', 'HHPM')
but I still obtain the following error:
Error using set
Conversion to double from cell is not possible.
I wonder if someone could help me to correct these command lines and avoid the use of subplot.
Thank you in advance for your help
Emerson

Best Answer

Plots do not have ticks, axes have ticks.
h = plot(xdate,count);
haxis = ancestor(h, 'axes');
set(haxis, 'XTick', xdate);
datetick(haxis, 'x', 'HHPM')