Graphics

XData and YData

The XData and YData properties control the coordinate system of the image. For an m-by-n image, the default XData is [1 n] and the default YData is [1 m]. These settings imply the following:

• The left column of the image has an x-coordinate of 1.
• The right column of the image has an x-coordinate of n.
• The top row of the image has a y-coordinate of 1.
• The bottom row of the image has a y-coordinate of m.

For example, the statements,

X = [1 2 3 4; 5 6 7 8; 9 10 11 12];
h = image(X); colormap(colorcube(12))
xlabel x; ylabel y

produce the picture.

The XData and YData properties of the resulting image object have the default values shown below.

get(h,'XData')
ans =

     1     4

get(h,'YData')
ans =

     1     3

However, you can override the default settings to specify your own coordinate system. For example, the statements,

X = [1 2 3 4; 5 6 7 8; 9 10 11 12];
image(X,'XData',[-1 2],'YData',[2 4]); colormap(colorcube(12))
xlabel x; ylabel y

produce the picture.

CDataMapping

EraseMode