pygmt.Figure.contour

Figure.contour(x=None, y=None, z=None, data=None, *, annotation=None, frame=None, levels=None, label_placement=None, projection=None, triangular_mesh_pen=None, no_clip=None, region=None, skip=None, timestamp=None, verbose=None, pen=None, xshift=None, yshift=None, binary=None, panel=None, nodata=None, find=None, coltypes=None, header=None, incols=None, label=None, perspective=None, transparency=None, **kwargs)

Contour table data by direct triangulation.

Takes a matrix, (x,y,z) pairs, or a file name as input and plots lines, polygons, or symbols at those locations on a map.

Must provide either data or x/y/z.

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

Aliases:

• A = annotation

• B = frame

• C = levels

• G = label_placement

• J = projection

• L = triangular_mesh_pen

• N = no_clip

• R = region

• S = skip

• U = timestamp

• V = verbose

• W = pen

• X = xshift

• Y = yshift

• b = binary

• c = panel

• d = nodata

• e = find

• f = coltypes

• h = header

• i = incols

• l = label

• p = perspective

• t = transparency

Parameters

• x/y/z (1d arrays) – Arrays of x and y coordinates and values z of the data points.

• data (str or numpy.ndarray or pandas.DataFrame or xarray.Dataset or geopandas.GeoDataFrame) – Pass in (x, y, z) or (longitude, latitude, elevation) values by providing a file name to an ASCII data table, a 2D numpy.ndarray, a pandas.DataFrame, an xarray.Dataset made up of 1D xarray.DataArray data variables, or a geopandas.GeoDataFrame containing the tabular data

• 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.

• annotation (str or int) –

  Specify or disable annotated contour levels, modifies annotated contours specified in interval.

  • Specify a fixed annotation interval annot_int or a single annotation level +annot_int.

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

• levels (str or int) –

  Specify the contour lines to generate.

  • The filename of a CPT file where the color boundaries will be used as contour levels.

  • The filename of a 2 (or 3) column file containing the contour levels (col 1), (C)ontour or (A)nnotate (col 2), and optional angle (col 3)

  • A fixed contour interval cont_int or a single contour with +cont_int

• D (str) – Dump contour coordinates.

• E (str) – Network information.

• label_placement (str) – [d|f|n|l|L|x|X]args. Control the placement of labels along the quoted lines. It supports five controlling algorithms. See https://docs.generic-mapping-tools.org/latest/contour.html#g for details.

• I (bool) – Color the triangles using CPT.

• triangular_mesh_pen (str) – Pen to draw the underlying triangulation [Default is none].

• no_clip (bool) – Do NOT clip contours or image at the boundaries [Default will clip to fit inside region].

• Q (float or str) – [cut][+z]. Do not draw contours with less than cut number of points.

• skip (bool or str) – [p|t]. Skip input points outside region.

• pen (str) – Set pen attributes for lines or the outline of symbols.

• label (str) – Add a legend entry for the contour being plotted. Normally, the annotated contour is selected for the legend. You can select the regular contour instead, or both of them, by considering the label to be of the format [annotcontlabel][/contlabel]. If either label contains a slash (/) character then use | as the separator for the two labels instead.

• 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

• 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.

• binary (bool or str) –

  i|o[ncols][type][w][+l|b]. Select native binary input (using binary="i") or output (using binary="o"), where ncols is the number of data columns of type, which must be one of:

  • c - int8_t (1-byte signed char)

  • u - uint8_t (1-byte unsigned char)

  • h - int16_t (2-byte signed int)

  • H - uint16_t (2-byte unsigned int)

  • i - int32_t (4-byte signed int)

  • I - uint32_t (4-byte unsigned int)

  • l - int64_t (8-byte signed int)

  • L - uint64_t (8-byte unsigned int)

  • f - 4-byte single-precision float

  • d - 8-byte double-precision float

  • x - use to skip ncols anywhere in the record

  For records with mixed types, append additional comma-separated combinations of ncols type (no space). The following modifiers are supported:

  • w after any item to force byte-swapping.

  • +l|b to indicate that the entire data file should be read as little- or big-endian, respectively.

  Full documentation is at https://docs.generic-mapping-tools.org/latest/gmt.html#bi-full.

• panel (bool or int or list) – [row,col|index]. Select 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.

• nodata (str) – i|onodata. Substitute specific values with NaN (for tabular data). For example, d="-9999" will replace all values equal to -9999 with NaN during input and all NaN values with -9999 during output. Prepend i to the nodata value for input columns only. Prepend o to the nodata value for output columns only.

• find (str) – [~]“pattern” | [~]/regexp/[i]. Only pass records that match the given pattern or regular expressions [Default processes all records]. Prepend ~ to the pattern or regexp to instead only pass data expressions that do not match the pattern. Append i for case insensitive matching. This does not apply to headers or segment headers.

• coltypes (str) – [i|o]colinfo. Specify data types of input and/or output columns (time or geographical data). Full documentation is at https://docs.generic-mapping-tools.org/latest/gmt.html#f-full.

• header (str) –

  [i|o][n][+c][+d][+msegheader][+rremark][+ttitle]. Specify that input and/or output file(s) have n header records [Default is 0]. Prepend i if only the primary input should have header records. Prepend o to control the writing of header records, with the following modifiers supported:

  • +d to remove existing header records.

  • +c to add a header comment with column names to the output [Default is no column names].

  • +m to add a segment header segheader to the output after the header block [Default is no segment header].

  • +r to add a remark comment to the output [Default is no comment]. The remark string may contain \n to indicate line-breaks.

  • +t to add a title comment to the output [Default is no title]. The title string may contain \n to indicate line-breaks.

  Blank lines and lines starting with # are always skipped.

• incols (str or 1d array) –

  Specify data columns for primary input in arbitrary order. Columns can be repeated and columns not listed will be skipped [Default reads all columns in order, starting with the first (i.e., column 0)].

  • For 1d array: specify individual columns in input order (e.g., incols=[1,0] for the 2nd column followed by the 1st column).

  • For str: specify individual columns or column ranges in the format start[:inc]:stop, where inc defaults to 1 if not specified, with columns and/or column ranges separated by commas (e.g., incols="0:2,4+l" to input the first three columns followed by the log-transformed 5th column). To read from a given column until the end of the record, leave off stop when specifying the column range. To read trailing text, add the column t. Append the word number to t to ingest only a single word from the trailing text. Instead of specifying columns, use incols="n" to simply read numerical input and skip trailing text. Optionally, append one of the following modifiers to any column or column range to transform the input columns:

    • +l to take the log10 of the input values.

    • +d to divide the input values by the factor divisor [Default is 1].

    • +s to multiple the input values by the factor scale [Default is 1].

    • +o to add the given offset to the input values [Default is 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.contour

Contours