Figure.scalebar: Add a scale bar on maps

[seisman]

This issue serves as the central place for discussing and tracking the implementation of the Figure.scalebar method in PyGMT. The issue will be closed when the initial implementation is complete. Progress is tracked at PyGMT: Wrapping GMT modules.

Figure.scalebar is a thin wrapper for the -L option of the basemap module.

Documentation

• GMT: https://docs.generic-mapping-tools.org/dev/basemap.html
• GMT.jl: https://www.generic-mapping-tools.org/GMTjl_doc/documentation/modules/basemap
• PyGMT: https://www.pygmt.org/dev/api/generated/pygmt.Figure.scalebar.html

GMT Option Flags and Modifiers

☑️: Implemented; ⬜: To be implemented/discussed; Strikethrough: Won't implement.

Below are the option flags and modifiers of the basemap module.

• -R: region
• -J: projection
• -Jz/-JZ: zscale/zsize
• -A: Dumping polygons of bounding box. Make no sense here.
• -B: frame
• -F: box Add Figure.scalebar to plot a scale bar on maps #4015
• -L: -L[g|j|J|n|x]refpoint+wlength[e|f|k|M|n|u][+aalign][+c[[slon/]slat]][+f][+jjustify][+l[label]][+odx[/dy]][+u][+v]
  • g|j|J|n|x]refpoint[+jjustify][+odx[/dy]]: position Add Figure.scalebar to plot a scale bar on maps #4015
  • +wlength: length Add Figure.scalebar to plot a scale bar on maps #4015
  • +a: label_alignment Add Figure.scalebar to plot a scale bar on maps #4015
  • +c: scale_location Add Figure.scalebar to plot a scale bar on maps #4015
  • +l: label Add Figure.scalebar to plot a scale bar on maps #4015
  • +u: unit Add Figure.scalebar to plot a scale bar on maps #4015
  • +v: vertical Add Figure.scalebar to plot a scale bar on maps #4015
  • MAP_SCALE_HEIGHT: height Add Figure.scalebar to plot a scale bar on maps #4015
• -Td: Add a directional rose
• -Tm: Add a magnatic rose
• -U: Use Figure.timestamp instead.
• -V: verbose Add Figure.scalebar to plot a scale bar on maps #4015
• -X/-Y: Use Figure.shift_origin instead.
• -c: panel Add Figure.scalebar to plot a scale bar on maps #4015
• -f: Makes no sense in Figure.scalebar
• -p: perspective Add Figure.scalebar to plot a scale bar on maps #4015
• -t: transparency Add Figure.scalebar to plot a scale bar on maps #4015
• --PAR=value: Use pygmt.config instead.

Linked Pull Requests

• Initial feature implementation Add Figure.scalebar to plot a scale bar on maps #4015 @seisman
• Add a tutorial or gallery example

Related Issues and Discussions

Add links to related wrapper discussions, API design threads, or upstream GMT changes here.