@lorenpeve10

To understand the three types of refs: 1) “x”, “y”, 2) “paper”, 3) “x domain”, “y domain”, read their presentation here:

https://plotly.com/python/reference/layout/annotations/#layout-annotations-items-annotation-xref:

```
xref
Type: enumerated , one of ( "paper" | "/^x([2-9]|[1-9][0-9]+)?( domain)?$/" ) Sets the annotation's x coordinate axis. If set to a x axis id (e.g. "x" or "x2"), the x position refers to a x coordinate. If set to "paper", the x position refers to the distance from the left of the plotting area in normalized coordinates where "0" ("1") corresponds to the left (right). If set to a x axis ID followed by "domain" (separated by a space), the position behaves like for "paper", but refers to the distance in fractions of the domain length from the left of the domain of that axis: e.g., "x2 domain" refers to the domain of the second x axis and a x position of 0.5 refers to the point between the left and the right of the domain of the second x axis.
```

then look at these examples and the corresponding plots:

```
import plotly.graph_objects as go
fig=go.Figure(go.Scatter(x=[0,2,3], y=[0.5, -0.75, 1.63]))
fig.update_layout(width=600, height=500, xaxis_range=[-1, 4]);
fig.add_annotation(x=1,#annot placed at the point of coords(x,y)=(1,1) with respect to axes
y=1,
xref="x",
yref="y",
text="refs 'x', 'y'<br>(1,1)",
showarrow=False,
align="center",
)
fig.add_annotation(x=1, #annot places in the upper-right corner of the plot area
y=1,
xref="paper",
yref="paper",
text="refs paper<br>(1,1)",
showarrow=False
)
fig.add_annotation(x=1.15, #annot outside plot area (at right of it, i.e. x>1)
y=0.4,
xref="paper",
yref="paper",
text="refs paper<br>(1.15,0.4)",
showarrow=False,
align="right",
xanchor="right"
)
fig.add_annotation(x=0.5,#annot outside plot area (above it, i.e. y>1)
y=1.2,
xref="paper",
yref="paper",
text="refs paper<br>(0.5,1.2)",
showarrow=False,
align="right",
)
fig.add_annotation(x=0,#annot outside plot area (below it, i.e y<0)
y=-0.25,
xref="paper",
yref="paper",
text="refs paper<br>(0,-0.25)",
showarrow=False,
)
fig.update_layout(showlegend=False)
fig.show()
```

```
from plotly.subplots import make_subplots
fig1= make_subplots(rows=1, cols=2)
fig1.add_trace(go.Scatter(
x=[0, 1, 2, 3, 4, 5, 6, 7, 8],
y=[0, 1, 3, 2, 4, 3, 4, 6, 5]
), 1, 1)
fig1.add_trace(go.Scatter(
x=[0, 1, 2, 3, 4, 5, 6, 7, 8],
y=[0, 4, 5, 1, 2, 2, 3, 4, 2]
), 1, 2)
fig1.update_layout(width=900, height=500)
fig1.add_annotation(x=0.6, #annot similar to ref "paper" when the fig contains only one subpl,
#but here within plot area of the second trace
y=0.75,
xref="x2 domain",
yref="y2 domain",
text="refs domain<br>(0.6,0.75)",
showarrow=False,
align="center",
)
fig1.add_annotation(x=0.5, #annot with respect to "paper", below the fig plot area
y=-0.15,
xref="paper",
yref="paper",
text="refs paper<br>(0.5,-0.15)",
showarrow=False,
align="center",
)
fig1.add_annotation(x=6, #annot with respect to xaxis 1, yaxis1
y=1.5,
xref="x1",
yref="y1",
text="refs x1, y1<br>(6,1.5)",
showarrow=False,
align="center",
)
fig1.add_annotation(x=4, #annot with respect to xaxis2, yaxis2
y=4.5,
xref="x2",
yref="y2",
text="refs x2, y2<br>(4,4.5)",
showarrow=False,
align="center",
)
```