Automatic positioning of text on the chart

Hello, I often rearrange the schedule and I have to correct the text placement position every time. Is it possible to set its position as, for example, the center of the visible graph window?

Now the text flies out of the visible part of the graph when the limits change

x = 0:100;
y = log10(x);
plot(x, y)
t= text(0.5, 0.5, 'y = log_{10}(x)')
s = t.FontSize;
t.FontSize = 24;

Answer 1

[Jiri Hajek]

Hi, you can get the desired behaviour using annotation (see https://www.mathworks.com/help/matlab/ref/annotation.html).

[Walter Roberson]

Note: it is not possible to position an annotation by data coordinates. You can position using normalized coordinates, if you wanted to do something like display in the middle of whatever is being shown, but you cannot anchor an annotation so that it moves as you pan or zoom (not without more work with callbacks)

[Anton Tayurov]

Please tell me how I can use normalized coordinates?

[Walter Roberson]

When you call annotation() the position units already default to 'normalized', so you do not need to do anything special: just pass on values that are a fraction of the position of the container being annotated.

Note however that a normalized unit of 0.5 on the width would be relative to the whole axes, not to the drawing area. As your axes labels are often on the left, the middle of the drawing area is typically more than halfway to the right. See also the axes InnerPosition property, which might give you information to calculate the drawing area.