diff --git a/examples/gallery/embellishments/scalebar.py b/examples/gallery/embellishments/scalebar.py index 569d3131ae5..5ddfa91ba97 100644 --- a/examples/gallery/embellishments/scalebar.py +++ b/examples/gallery/embellishments/scalebar.py @@ -1,48 +1,14 @@ -r""" +""" Scale bar ========= -The ``map_scale`` parameter of the :meth:`pygmt.Figure.basemap` and -:meth:`pygmt.Figure.coast` methods is used to add a scale bar to a map. -This example shows how such a scale bar can be customized: - - - position: **g**\|\ **j**\|\ **J**\|\ **n**\|\ **x**. Set the position - of the reference point. Choose from - - - **g**: Give map coordinates as *longitude*\/\ *latitude*. - - **j**\|\ **J**: Specify a - :doc:`2-character justification code `. - Lower / uppercase **j** / **J** mean inside / outside of the map - bounding box. - - **n**: Give normalized bounding box coordinates as *nx*\/\ *ny*. - - **x**: Give plot coordinates as *x*\/\ *y*. - - - length: **+w**. Give a distance value, and, optionally a distance unit. - Choose from **e** (meters), **f** (feet), **k** (kilometers) [Default], - **M** (statute miles), **n** (nautical miles), or **u** (US survey feet). - - origin: **+c**\ [*slon*/]\ *slat*. Control where on the map the scale bar - applies. If **+c** is not given the reference point is used. If only - **+c** is appended the middle of the map is used. Note that *slon* is only - optional for projections with constant scale along parallels, e.g., - Mercator projection. - - justify: **+j**. Set the anchor point. Specify a - :doc:`2-character justification code `. - - offset: **+o**\ *offset* or **+o**\ *xoffset*/\ *yoffset*. Give either a - common shift or individual shifts in x- (longitude) and y- (latitude) - directions. - - height: Use :gmt-term:`MAP_SCALE_HEIGHT` via :func:`pygmt.config`. - - fancy style: **+f**. Get a scale bar that looks like train tracks. - - unit: **+u**. Add the distance unit given via **+w** to the single - distance values. - - label: **+l**. Add the distance unit given via **+w** as label. Append - text to get a customized label instead. - - alignment: **+a**. Set the label alignment. Choose from **t**\(op) - [Default], **b**\(ottom), **l**\(eft), or **r**\(ight). +The :meth:`pygmt.Figure.scalebar` method can be used to add a scale bar to a map. This +example shows how such a scale bar can be customized. """ # %% import pygmt -from pygmt.params import Box +from pygmt.params import Box, Position # Create a new Figure instance fig = pygmt.Figure() @@ -50,60 +16,69 @@ # Mercator projection with 10 centimeters width fig.basemap(region=[-45, -25, -15, 0], projection="M0/0/10c", frame=["WSne", "af"]) -# ----------------------------------------------------------------------------- -# Top Left: Add a plain scale bar -# It is placed based on geographic coordinates (g) 42° West and 1° South, -# applies at the reference point (+c is not given), and represents a -# length (+w) of 500 kilometers -fig.basemap(map_scale="g-42/-1+w500k") - -# ----------------------------------------------------------------------------- -# Top Right: Add a fancy scale bar -# It is placed based on normalized bounding box coordinates (n) -# Use a fancy style (+f) to get a scale bar that looks like train tracks -# Add the distance unit (+u) to the single distance values -fig.basemap(map_scale="n0.8/0.95+w500k+f+u") +# --- Top Left: Add a plain scale bar --- +# It is placed based on geographic coordinates 42° West and 1° South, applies at the +# reference point by default, and represents a length of 500 kilometers. +fig.scalebar(length="500k", position=Position((-42, -1), cstype="mapcoords")) + +# --- Top Right: Add a fancy scale bar --- +# It is placed based on normalized bounding box coordinates. Use a fancy style to get a +# scale bar that looks like train tracks. Add the distance unit to the single distance +# values. +fig.scalebar( + position=Position((0.8, 0.95), cstype="boxcoords"), + length="500k", + fancy=True, + unit=True, +) -# ----------------------------------------------------------------------------- -# Bottom Left: Add a thick scale bar -# Adjust the GMT default parameter MAP_SCALE_HEIGHT locally (the change applies -# only to the code within the "with" statement) -# It applies (+c) at the middle of the map (no location is appended to +c) -# Without appending text, +l adds the distance unit as label -with pygmt.config(MAP_SCALE_HEIGHT="10p"): - fig.basemap(map_scale="n0.2/0.15+c+w500k+f+l") +# --- Bottom Left: Add a thick scale bar --- +# It applies at the middle of the map (scale_loc is set to True). Use the height +# parameter to adjust the thickness of the scale bar Without providing text, the label +# parameter adds the distance unit as label. +fig.scalebar( + position=Position((0.2, 0.15), cstype="boxcoords"), + scale_loc=True, + length="500k", + height="10p", + fancy=True, + label=True, +) -# ----------------------------------------------------------------------------- -# Bottom Right: Add a scale bar valid for a specific location -# It is placed at BottomRight (j) using MiddleRight as anchor point (+j) with -# an offset (+o) of 1 centimeter in both x- and y-directions -# It applies (+c) at -7° South, add a customized label by appending text to +l -fig.basemap(map_scale="jBR+jMR+o1c/1c+c-7+w500k+f+u+lvalid at 7° S") +# --- Bottom Right: Add a scale bar valid for a specific location --- +# It is placed at BottomRight using MiddleRight as anchor point with an offset of 1 +# centimeter in both x- and y-directions. It applies at -7° South. A customized label +# is added via the label parameter. +fig.scalebar( + position=Position("BR", anchor="MR", offset=1), + scale_loc=-7, + length="500k", + fancy=True, + unit=True, + label="valid at 7° S", +) fig.show() # %% -# The ``box`` parameter allows surrounding the scale bar. This can be useful -# when adding a scale bar to a colorful map. To fill the box, append **+g** -# with the desired color (or pattern). The outline of the box can be adjusted -# by appending **+p** with the desired thickness, color, and style. To force -# rounded edges append **+r** with the desired radius. +# The ``box`` parameter allows surrounding the scale bar. This can be useful when adding +# a scale bar to a colorful map to improve contrast and readability. -# Create a new Figure instance fig = pygmt.Figure() -fig.coast( - region=[-45, -25, -15, 0], - projection="M10c", - land="tan", - water="steelblue", - frame=["WSne", "af"], - # Set the label alignment (+a) to right (r) - map_scale="jBL+o1c/1c+c-7+w500k+f+lkm+ar", - # Fill the box in white with a transparency of 30 percent, add a solid - # outline in darkgray (gray30) with a thickness of 0.5 points, and use - # rounded edges with a radius of 3 points +fig.basemap(region=[-45, -25, -15, 0], projection="M10c", frame=["WSne", "af"]) +fig.coast(land="tan", water="steelblue") +fig.scalebar( + position=Position("BL", cstype="inside", offset=1), + scale_loc=-7, + length="500k", + fancy=True, + label="km", + label_alignment="right", + # Fill the box in white with a transparency of 30 percent, add a solid outline in + # darkgray (gray30) with a thickness of 0.5 points, and use rounded edges with a + # radius of 3 points box=Box(fill="white@30", pen="0.5p,gray30,solid", radius="3p"), )