Merge pull request #104 from FloraSauerbronn/create-plotting

Creating plotting.py with pandas-flavor

gliderpy/__init__.py

@@ -4,3 +4,11 @@
     from ._version import __version__
 except ImportError:
     __version__ = "unknown"
+
+from .fetchers import GliderDataFetcher
+from .plotting import plot_transect
+
+__all__ = [
+    "GliderDataFetcher",
+    "plot_transect",
+]

gliderpy/plotting.py

@@ -0,0 +1,57 @@
+"""Some convenience functions to help visualize glider data."""
+
+from __future__ import annotations
+
+import warnings
+from typing import TYPE_CHECKING
+
+try:
+    import matplotlib.dates as mdates
+    import matplotlib.pyplot as plt
+except ModuleNotFoundError:
+    warnings.warn(
+        "gliderpy requires matplotlib and cartopy for plotting.",
+        stacklevel=1,
+    )
+    raise
+
+
+if TYPE_CHECKING:
+    import pandas as pd
+
+from pandas_flavor import register_dataframe_method
+
+
+@register_dataframe_method
+def plot_transect(
+    df: pd.DataFrame,
+    var: str,
+    **kw: dict,
+) -> tuple(plt.Figure, plt.Axes):
+    """Make a scatter plot of depth vs time coloured by a user defined
+    variable.
+
+    :param var: variable to colour the scatter plot
+    :return: figure, axes
+    """
+    cmap = kw.get("cmap", None)
+
+    fig, ax = plt.subplots(figsize=(17, 2))
+    cs = ax.scatter(
+        df.index,
+        df["pressure"],
+        s=15,
+        c=df[var],
+        marker="o",
+        edgecolor="none",
+        cmap=cmap,
+    )
+
+    ax.invert_yaxis()
+    xfmt = mdates.DateFormatter("%H:%Mh\n%d-%b")
+    ax.xaxis.set_major_formatter(xfmt)
+
+    cbar = fig.colorbar(cs, orientation="vertical", extend="both")
+    cbar.ax.set_ylabel(var)
+    ax.set_ylabel("pressure")
+    return fig, ax