"""
Scatter plot with histograms
============================

To create a scatter plot with histograms at the sides of the plot one can use
:meth:`pygmt.Figure.plot` in combination with :meth:`pygmt.Figure.histogram`. The
positions of the histograms are plotted by offsetting them from the main scatter plot
using :meth:`pygmt.Figure.shift_origin`.
"""

# %%
import numpy as np
import pygmt

# Generate random x, y coordinates from a standard normal distribution.
# x values are centered on 0 with a standard deviation of 1, and y values are centered
# on 30 with a standard deviation of 2.
rng = np.random.default_rng()
x = rng.normal(loc=0, scale=1, size=1000)
y = rng.normal(loc=30, scale=2, size=1000)

# Get axis limits from the data limits. Extend the limits by 0.5 to add some margin.
xmin = np.floor(x.min()) - 0.5
xmax = np.ceil(x.max()) + 0.5
ymin = np.floor(y.min()) - 0.5
ymax = np.ceil(y.max()) + 0.5

# Set fill color for symbols and bars.
fill = "seagreen"

# Set the dimensions of the scatter plot.
width, height = 10, 8

fig = pygmt.Figure()
fig.basemap(
    region=[xmin, xmax, ymin, ymax],
    projection=f"X{width}/{height}",
    frame=["WSrt", "af"],
)

# Plot data points as circles with a diameter of 0.15 centimeters and set transparency
# level for all circles to deal with overplotting.
fig.plot(x=x, y=y, style="c0.15c", fill=fill, transparency=50)

# Shift the plot origin and add top margin histogram.
fig.shift_origin(yshift=height + 0.25)

fig.histogram(
    projection=f"X{width}/3",
    frame=["Wsrt", "xf", "yaf+lCounts"],
    # Give the same value for ymin and ymax to have them calculated automatically.
    region=[xmin, xmax, 0, 0],
    data=x,
    fill=fill,
    pen="0.1p,white",
    histtype=0,
    series=0.2,
)

# Shift the plot origin and add right margin histogram.
fig.shift_origin(yshift=-height - 0.25, xshift=width + 0.25)

# Plot the horizontal histogram.
fig.histogram(
    horizontal=True,
    projection=f"X3/{height}",
    # Note that the x- and y-axis are flipped, with the y-axis plotted horizontally.
    frame=["wSrt", "xf", "yaf+lCounts"],
    region=[ymin, ymax, 0, 0],
    data=y,
    fill=fill,
    pen="0.1p,white",
    histtype=0,
    series=0.2,
)
fig.show()