000_general: Add first version of colorwheel

000_general_stuff/02_colorwheel/colorwheel_pygmt.py

@@ -0,0 +1,117 @@
+# #############################################################################
+# Colorwheel for cyclic colormaps created with PyGMT
+# Scientific colourmaps by Fabio Crameri: romaO, bamO, brocO, corkO, vikO
+# cmocean colormaps by Kristen M. Thyng: phase
+# -----------------------------------------------------------------------------
+# Created: 2024/05/20
+# Author: Yvonne Fröhlich
+# ORCID: https://orcid.org/0000-0002-8566-0619
+# GitHub: https://github.com/yvonnefroehlich/gmt-pygmt-plotting
+# -----------------------------------------------------------------------------
+# - Created: 2024/05/15
+#   PyGMT v0.12.0 -> https://www.pygmt.org/v0.12.0/ | https://www.pygmt.org/
+#   GMT 6.5.0 -> https://www.generic-mapping-tools.org/
+# #############################################################################
+
+
+import numpy as np
+import pygmt
+
+
+def colorwheel(cmap, perspective, rho_min=1, rho_max=2.5, fig_instance=None):
+    """
+    -------------------------------------------------------------------------
+    Parameters
+    -------------------------------------------------------------------------
+    Required
+    - cmap : str | name of a cyclic colormap
+    - perspective : list of two floats | azimuth, elevation
+    Optional
+    - rho_min : float | inner radius of colorwheel | Default 1
+    - rho_max : float | outer radius of colorwheel | Default 2.5
+    - fig_instance : Provide a PyGMT figure instance | Default a new one is set up
+    """
+
+    # -------------------------------------------------------------------------
+    # Set up rotated rectangle or bar data
+    # -------------------------------------------------------------------------
+    # [[lon, lat, direction, width, height]]
+    # In polar coordinates lon refers to the angle and lat to the radius (rho)
+    # Location applies to the center of the bar -> shift by length/2
+    # Add quantity for fill color as second column (zero-based indexing)
+    # Direction of bar (j) is from North but still counter-clockwise -> negative sign
+    data_bars = np.zeros([360, 6])
+    for i_ang in range(0, 360, 1):  # min, max], step
+        data_bars_temp = np.array([
+            i_ang, rho_min+rho_max/2, i_ang, -i_ang, 0.05, rho_max-rho_min,
+        ])
+        data_bars[i_ang,:] = data_bars_temp
+
+    # -------------------------------------------------------------------------
+    # Create colorwheel plot
+    # -------------------------------------------------------------------------
+    if fig_instance != None:
+        fig = fig_instance
+    else:
+        fig = pygmt.Figure()
+
+    with pygmt.config(
+        PS_PAGE_COLOR="white@1", # Make area outside of plot transparent
+        MAP_FRAME_PEN="white", # Make frame outline white
+    ):
+        fig.basemap(
+            region=[0, 360, 0, rho_max],
+            # Use geographic azimuth instead of standard angle -> backazimuth
+            # Go clockwise from North instead of counter-clockwise from East
+            projection=f"P{rho_max * 2}c+a",
+            frame="rltb",
+        )
+
+    # Create colormap for direction (backazimuth)
+    pygmt.makecpt(cmap=cmap, cyclic=True, series=[0, 360, 1])
+
+    # Plot rotated rectangles with color-coding
+    # Set perspective as [azimuth, elevation]
+    fig.plot(data=data_bars, style="j", cmap=True, perspective=perspective)
+
+    # Show and save
+    fig_name = f"colorwheel_N_cw_pygmt_bar_{cmap}"
+    if fig_instance == None:
+        fig.show()
+        for ext in ["png"]: #, "pdf", "eps"]:
+            fig.savefig(fname=f"{fig_name}.{ext}", dpi=720)
+    print(fig_name)
+
+
+# %%
+# -----------------------------------------------------------------------------
+# Examples
+# -----------------------------------------------------------------------------
+fig = pygmt.Figure()
+fig.basemap(region=[-5, 5, -2, 2], projection="X10c/4c", frame=0)
+
+fig.shift_origin(xshift="0.6c", yshift="2c")
+for cmap in ["romaO", "bamO", "brocO", "corkO", "vikO", "phase"]:
+
+    colorwheel(
+        cmap=cmap,
+        perspective=[90, -90],  # anti-clockwise from horizontal
+        rho_min=0.2,
+        rho_max=0.6,
+        fig_instance=fig,
+    )
+    fig.shift_origin(yshift="-1.4c")
+    colorwheel(
+        cmap=cmap,
+        perspective=[180, 90],  # clockwise from vertical (-> backazimuth)
+        rho_min=0.2,
+        rho_max=0.6,
+        fig_instance=fig,
+    )
+    fig.text(x=1, y=2.4, text=cmap, no_clip=True)
+    pygmt.makecpt(cmap=cmap, series=[0, 360], cyclic=True)
+    fig.colorbar(cmap=True, position="jBC+o0c/-0.5c+w1.1c/0.25c+h", frame=0)
+    fig.shift_origin(xshift="1.5c", yshift="1.4c")
+
+fig.show()
+fig.savefig(fname="colorwheel_all_cmaps.png")

000_general_stuff/README.md

@@ -5,6 +5,7 @@
 _Recommended versions_: PyGMT v0.11.0 / v0.12.0 / v0.13.0, GMT 6.4.0 / 6.5.0
 
 - **[01_custom_symbols](https://github.com/yvonnefroehlich/gmt-pygmt-plotting/tree/main/000_general_stuff/01_custom_symbols)**
+- **[02_colorwheel](https://github.com/yvonnefroehlich/gmt-pygmt-plotting/tree/main/000_general_stuff/02_colorwheel)**
 - **[03_cb_font_scaling](https://github.com/yvonnefroehlich/gmt-pygmt-plotting/tree/main/000_general_stuff/03_cb_font_scaling)**
 
 ![](https://github.com/yvonnefroehlich/gmt-pygmt-plotting/raw/main/_images/github_maps_readme_000general.png)

README.md

@@ -29,7 +29,7 @@ If you make use of this material, please acknowledge the relating publications i
 
 ## Content
 
-- **[000_general_stuff](https://github.com/yvonnefroehlich/gmt-pygmt-plotting/tree/main/000_general_stuff)**: Custom symbols
+- **[000_general_stuff](https://github.com/yvonnefroehlich/gmt-pygmt-plotting/tree/main/000_general_stuff)**: Custom symbols, colorwheel
 - **[001_paper_RFSG_2022](https://github.com/yvonnefroehlich/gmt-pygmt-plotting/tree/main/001_paper_RFSG_2022)**: Maps of [**_Ritter et al. (2022)_**](https://doi.org/10.1007/s10950-022-10112-w)
 - **[002_paper_FGR_2024](https://github.com/yvonnefroehlich/gmt-pygmt-plotting/tree/main/002_paper_FGR_2024)**: Maps of [**_Fröhlich et al. (2024)_**](https://doi.org/10.1093/gji/ggae245)
 - **[003_taup](https://github.com/yvonnefroehlich/gmt-pygmt-plotting/tree/main/003_taup)**: Travel paths of seismological phases through the Earth interior; related to [**_Fröhlich et al. (2024)_**](https://doi.org/10.1093/gji/ggae245)