Matlab changes XAXIS order

I have two simple matrixes: X is time of day in hours:

 X[ 6 7 8 9 10 11 12 1 2 3 4 5 ]
 Y[ various values......       ]

When I plot, MATLAB rearranges order of axis so x axis is:

[ 1 2 3 4 5 6 etc...}

I need MATLAB to plot in order as shown originally.

Answer 1

[Azzi Abdelmalek]

x=[ 6 7 8 9 10 11 12 1 2 3 4 5 ]
y=sin(x)
x1=1:numel(x)
plot(x1,y)
set(gca,'xtick',x1,'xticklabel',x)

Answer 2

[Walter Roberson]

cX = unwrap(X*pi/6)*6/pi;
plot(cX, Y);

The unwrap() is a trick to convert the 12-hour based clock times into continuous hour based clock times (so if you had several 12 hour periods the count would just keep increasing.)

You can use tick labels to change the labeling. For example,

X = repmat(1:24,1,3)/2;
cX = unwrap(X*pi/6)*6/pi;
Y = X.^3;
plot(cX, Y)
set(gca, 'XTick', cX(2:2:end), 'XTickLabel', X(2:2:end));

The 2:2:end is to select out only the exact hours out of the particular sample X values that here are by the half hour.