Outputting text on subplot with mixed normalised/normal coordinates

I have subplot on a figure and i want to place some text outside the plot as below (i.e. the text '80th pct' and '20th pct'

I started off with

text(1,1,'Your String','Units','normalized')

Whilst I need the x coordinate to be at the extreme, the y coordiante depends on the y value of the green dotted line (that I know).

So I'm not sure how to mix the cooridnates so x is normalised but y is fixed by a variable. Or maybe there is a better way. (I have another 6 subplots on this figure)

Answer 1

[Walter Roberson]

There might be a different way, this is what comes to mind:

label_offset_pixels = 15;   %space in pixels between axes box and text to write

ax = gca;
old_units = get(ax, 'Units');
set(ax, 'Units', 'pixels');
ax_pos = get(ax, 'Position');
set(ax, 'Units', old_units);
label_x_pos_pixels = ax_pos(1) + ax_pos(3) + label_offset_pixels;
probe_text = text(label_x_pos_pixels, 1, 'test', 'Units', 'pixels');
set(probe_text, 'Units', 'data');
probe_pos_data = get(probe_text, 'Position');
label_x_pos_data = probe_pos_data(1);
delete(probe_text);

text(label_x_pos_data, y20, '20th pct');
text(label_x_pos_data, y80, '80th pct');

What this does is find the right boundary of the axes in pixels, add a margin, convert that to data units, and use the data units for the text position.

There is a considerably shorter way to find the normalized desired y coordinate, using the axes YLim properties, but that does not give you a fixed spacing between the box and the text. Though now that I think of it, you could do that, convert the result to Pixels, add the offset... yes, I guess that would be shorter in spirit

label_offset_pixels = 15;   %space in pixels between axes box and text to write

ax = gca;
ax_ylim = get(ax, 'Ylim');
normalized_y20_80 = ([y20, y80]-ax_ylim(1))./(ax_ylim(2)-ax_ylim(1));
pct_text = text([1, 1], normalized_y20_80, {'20th pct', '80th pct'});   %data units is default
set(pct_text, 'Units', 'pixel');
pct_text_pos = get(pct_text, 'Position');
set(pct_text, {'Position'}, cellfun(@(xyz) xyz+[label_offset_pixels 0 0], pct_text_pos,'Uniform', 0));
set(pct_text, 'Units', 'data');

[Jason]

Thanks for this Walter. Unfortunately its not displaying any text for either of your methods. There are also no errors.

Here are some of the outputs:

pct_text = 2x1 Text array:

Text    (20th pct)
Text    (80th pct)
pct_text_pos = 
  [1x3 double]
  [1x3 double]
ans =
  19    19
ans =
  19    19
ans =
      28931            4      0.63574       150.66

[Walter Roberson]

label_offset_pixels = 15;   %space in pixels between axes box and text to write

ax = gca;
ax_ylim = get(ax, 'Ylim');
normalized_y20_80 = ([y20, y80]-ax_ylim(1))./(ax_ylim(2)-ax_ylim(1));
pct_text = text([1, 1], normalized_y20_80, {'20th pct', '80th pct'}, 'Units', 'normal');
set(pct_text, 'Units', 'pixel');
pct_text_pos = get(pct_text, 'Position');
set(pct_text, {'Position'}, cellfun(@(xyz) xyz+[label_offset_pixels 0 0], pct_text_pos,'Uniform', 0));
set(pct_text, 'Units', 'normal');

[Jason]

Perfect, thankyou.