Adding arbitrary text --------------------- This uses the `Axes.text()` function. Note that in the script below, writing ``x=0.5, y=0.5`` refers to so-called *data* coordinates, i.e. 0.5 ppm in both dimensions. This is most straightforward for labelling 2D data. If you want *axes* coordinates, i.e. using ``x=0.5, y=0.5`` to refer to the middle of the spectrum, then you need to pass an extra argument ``transform=ax.transAxes`` to `text()`, where `ax` is the Axes instance you are plotting on. Coordinate transforms are covered very thoroughly in the :std:doc:`Matplotlib transforms tutorial`. Other keyword arguments (to control e.g. colour, font weight, or alignment) can be found in the Matplotlib documentation for `text()`. .. plot:: howto/add_text.py