pygmt.Figure.velo

Figure.velo(data=None, **kwargs)

Plot velocity vectors, crosses, anisotropy bars, and wedges.

Reads data values from files, numpy.ndarray or pandas.DataFrame and plots the selected geodesy symbol on a map. You may choose from velocity vectors and their uncertainties, rotational wedges and their uncertainties, anisotropy bars, or strain crosses. Symbol fills or their outlines may be colored based on constant parameters or via color lookup tables.

Must provide data and spec.

Full option list at https://docs.generic-mapping-tools.org/latest/supplements/geodesy/velo.html

Aliases:

  • A = vector

  • B = frame

  • C = cmap

  • D = rescale

  • E = uncertainty_color

  • G = color

  • H = scale

  • I = shading

  • J = projection

  • L = line

  • N = no_clip

  • R = region

  • S = spec

  • U = timestamp

  • V = verbose

  • W = pen

  • X = xshift

  • Y = yshift

  • Z = zvalue

  • c = panel

  • p = perspective

  • t = transparency

Parameters

  • data (str or numpy.ndarray or pandas.DataFrame) – Either a file name, a 2D numpy.ndarray or a pandas.DataFrame with the tabular data. Note that text columns are only supported with file or pandas DataFrame inputs.

  • spec (str) –

    Selects the meaning of the columns in the data file and the figure to be plotted. In all cases, the scales are in data units per length unit and sizes are in length units (default length unit is controlled by PROJ_LENGTH_UNIT unless c, i, or p is appended).

    • e[velscale/]confidence[+ffont]

      Velocity ellipses in (N,E) convention. The velscale sets the scaling of the velocity arrows. If velscale is not given then we read it from the data file as an extra column. The confidence sets the 2-dimensional confidence limit for the ellipse, e.g. 0.95 for 95% confidence ellipse. Use +f to set the font and size of the text [Default is 9p,Helvetica,black]; give +f0 to deactivate labeling. The arrow will be drawn with the pen attributes specified by the pen option and the arrow-head can be colored via color. The ellipse will be filled with the color or shade specified by the uncertainty_color option [Default is transparent], and its outline will be drawn if line is selected using the pen selected (by pen if not given by line). Parameters are expected to be in the following columns:

      • 1,2: longitude, latitude of station

      • 3,4: eastward, northward velocity

      • 5,6: uncertainty of eastward, northward velocities (1-sigma)

      • 7: correlation between eastward and northward components

      • Trailing text: name of station (optional)

    • n[barscale]

      Anisotropy bars. barscale sets the scaling of the bars. If barscale is not given then we read it from the data file as an extra column. Parameters are expected to be in the following columns:

      • 1,2: longitude, latitude of station

      • 3,4: eastward, northward components of anisotropy vector

    • r[velscale/]confidence[+ffont]

      Velocity ellipses in rotated convention. The velscale sets the scaling of the velocity arrows. If velscale is not given then we read it from the data file as an extra column. The confidence sets the 2-dimensional confidence limit for the ellipse, e.g. 0.95 for 95% confidence ellipse. Use +f to set the font and size of the text [Default is 9p,Helvetica,black]; give +f0 to deactivate labeling. The arrow will be drawn with the pen attributes specified by the pen option and the arrow-head can be colored via color. The ellipse will be filled with the color or shade specified by the uncertainty_color option [Default is transparent], and its outline will be drawn if line is selected using the pen selected (by pen if not given by line). Parameters are expected to be in the following columns:

      • 1,2: longitude, latitude of station

      • 3,4: eastward, northward velocity

      • 5,6: semi-major, semi-minor axes

      • 7: counter-clockwise angle, in degrees, from horizontal axis to major axis of ellipse.

      • Trailing text: name of station (optional)

    • w[wedgescale/]wedgemag

      Rotational wedges. The wedgescale sets the size of the wedges. If wedgescale is not given then we read it from the data file as an extra column. Rotation values are multiplied by wedgemag before plotting. For example, setting wedgemag to 1.e7 works well for rotations of the order of 100 nanoradians/yr. Use color to set the fill color or shade for the wedge, and uncertainty_color to set the color or shade for the uncertainty. Parameters are expected to be in the following columns:

      • 1,2: longitude, latitude of station

      • 3: rotation in radians

      • 4: rotation uncertainty in radians

    • x[cross_scale]

      Strain crosses. The cross_scale sets the size of the cross. If cross_scale is not given then we read it from the data file as an extra column. Parameters are expected to be in the following columns:

      • 1,2: longitude, latitude of station

      • 3: eps1, the most extensional eigenvalue of strain tensor, with extension taken positive.

      • 4: eps2, the most compressional eigenvalue of strain tensor, with extension taken positive.

      • 5: azimuth of eps2 in degrees CW from North.

  • projection (str) – Required if this is the first plot command. projcode[projparams/]width. Select map projection.

  • region (str or list) – Required if this is the first plot command. xmin/xmax/ymin/ymax[+r][+uunit]. Specify the region of interest.

  • vector (bool or str) – Modify vector parameters. For vector heads, append vector head size [Default is 9p]. See https://docs.generic-mapping-tools.org/latest/supplements/geodesy/velo.html#vector-attributes for specifying additional attributes.

  • frame (bool or str or list) – Set map boundary frame and axes attributes.

  • cmap (str) – File name of a CPT file or a series of comma-separated colors (e.g., color1,color2,color3) to build a linear continuous CPT from those colors automatically.

  • rescale (str) – can be used to rescale the uncertainties of velocities (spec='e' and spec='r') and rotations (spec='w'). Can be combined with the confidence variable.

  • uncertainty_color (str) – Sets the color or shade used for filling uncertainty wedges (spec='w') or velocity error ellipses (spec='e' or spec='r'). If uncertainty_color is not specified, the uncertainty regions will be transparent. Note: Using cmap and zvalue='+e' will update the uncertainty fill color based on the selected measure in zvalue [magnitude error]. More details at https://docs.generic-mapping-tools.org/latest/cookbook/features.html#gfill-attrib.

  • color (str) – Select color or pattern for filling of symbols [Default is no fill]. Note: Using cmap (and optionally zvalue) will update the symbol fill color based on the selected measure in zvalue [magnitude]. More details at https://docs.generic-mapping-tools.org/latest/cookbook/features.html#gfill-attrib.

  • scale (float or bool) – [scale]. Scale symbol sizes and pen widths on a per-record basis using the scale read from the data set, given as the first column after the (optional) z and size columns [Default is no scaling]. The symbol size is either provided by spec or via the input size column. Alternatively, append a constant scale that should be used instead of reading a scale column.

  • shading (float or bool) – intens. Use the supplied intens value (nominally in the -1 to +1 range) to modulate the symbol fill color by simulating illumination [Default is none]. If intens is not provided we will instead read the intensity from an extra data column after the required input columns determined by spec.

  • line (str) – [pen[+c[f|l]]]. Draw lines. Ellipses and rotational wedges will have their outlines drawn using the current pen (see pen). Alternatively, append a separate pen to use for the error outlines. If the modifier +cl is appended then the color of the pen is updated from the CPT (see cmap). If instead modifier +cf is appended then the color from the cpt file is applied to error fill only [Default]. Use just +c to set both pen and fill color.

  • no_clip (bool or str) – Do NOT skip symbols that fall outside the frame boundary specified by region. [Default plots symbols inside frame only].

  • timestamp (bool or str) – Draw GMT time stamp logo on plot.

  • verbose (bool or str) –

    Select verbosity level [Default is w], which modulates the messages written to stderr. Choose among 7 levels of verbosity:

    • q - Quiet, not even fatal error messages are produced

    • e - Error messages only

    • w - Warnings [Default]

    • t - Timings (report runtimes for time-intensive algorithms);

    • i - Informational messages (same as verbose=True)

    • c - Compatibility warnings

    • d - Debugging messages

  • pen (str) – [pen][+c[f|l]]. Set pen attributes for velocity arrows, ellipse circumference and fault plane edges. [Defaults: width = default, color = black, style = solid]. If the modifier +cl is appended then the color of the pen is updated from the CPT (see cmap). If instead modifier +cf is appended then the color from the cpt file is applied to symbol fill only [Default]. Use just +c to set both pen and fill color.

  • xshift (str) – [a|c|f|r][xshift]. Shift plot origin in x-direction.

  • yshift (str) – [a|c|f|r][yshift]. Shift plot origin in y-direction. Full documentation is at https://docs.generic-mapping-tools.org/latest/gmt.html#xy-full.

  • zvalue (str) – [m|e|n|u][+e]. Select the quantity that will be used with the CPT given via cmap to set the fill color. Choose from magnitude (vector magnitude or rotation magnitude), east-west velocity, north-south velocity, or user-supplied data column (supplied after the required columns). To instead use the corresponding error estimates (i.e., vector or rotation uncertainty) to lookup the color and paint the error ellipse or wedge instead, append +e.

  • panel (bool or int or list) – [row,col|index]. Selects a specific subplot panel. Only allowed when in subplot mode. Use panel=True to advance to the next panel in the selected order. Instead of row,col you may also give a scalar value index which depends on the order you set via autolabel when the subplot was defined. Note: row, col, and index all start at 0.

  • perspective (list or str) – [x|y|z]azim[/elev[/zlevel]][+wlon0/lat0[/z0]][+vx0/y0]. Select perspective view and set the azimuth and elevation angle of the viewpoint. Default is [180, 90]. Full documentation is at https://docs.generic-mapping-tools.org/latest/gmt.html#perspective-full.

  • transparency (int or float) – Set transparency level, in [0-100] percent range. Default is 0, i.e., opaque. Only visible when PDF or raster format output is selected. Only the PNG format selection adds a transparency layer in the image (for further processing).

Examples using pygmt.Figure.velo