Source code for pygmt.src.xyz2grd

"""
xyz2grd - Convert data table to a grid.
"""
from pygmt.clib import Session
from pygmt.exceptions import GMTInvalidInput
from pygmt.helpers import (
    GMTTempFile,
    build_arg_string,
    fmt_docstring,
    kwargs_to_strings,
    use_alias,
)
from pygmt.io import load_dataarray

__doctest_skip__ = ["xyz2grd"]


[docs]@fmt_docstring @use_alias( A="duplicate", G="outgrid", I="spacing", J="projection", R="region", V="verbose", Z="convention", b="binary", d="nodata", e="find", f="coltypes", h="header", i="incols", r="registration", w="wrap", ) @kwargs_to_strings(I="sequence", R="sequence") def xyz2grd(data=None, x=None, y=None, z=None, **kwargs): r""" Create a grid file from table data. Reads one or more tables with *x, y, z* columns and creates a binary grid file. xyz2grd will report if some of the nodes are not filled in with data. Such unconstrained nodes are set to a value specified by the user [Default is NaN]. Nodes with more than one value will be set to the mean value. Full option list at :gmt-docs:`xyz2grd.html` {aliases} Parameters ---------- data : str or {table-like} Pass in (x, y, z) or (longitude, latitude, elevation) values by providing a file name to an ASCII data table, a 2D {table-classes}. x/y/z : 1d arrays The arrays of x and y coordinates and z data points. outgrid : str or None Optional. The name of the output netCDF file with extension .nc to store the grid in. duplicate : str [**d**\|\ **f**\|\ **l**\|\ **m**\|\ **n**\|\ **r**\|\ **S**\|\ **s**\|\ **u**\|\ **z**]. By default we will calculate mean values if multiple entries fall on the same node. Use **-A** to change this behavior, except it is ignored if **-Z** is given. Append **f** or **s** to simply keep the first or last data point that was assigned to each node. Append **l** or **u** or **d** to find the lowest (minimum) or upper (maximum) value or the difference between the maximum and miminum value at each node, respectively. Append **m** or **r** or **S** to compute mean or RMS value or standard deviation at each node, respectively. Append **n** to simply count the number of data points that were assigned to each node (this only requires two input columns *x* and *y* as *z* is not consulted). Append **z** to sum multiple values that belong to the same node. {I} {J} {R} {V} convention : str [*flags*]. Read a 1-column ASCII [or binary] table. This assumes that all the nodes are present and sorted according to specified ordering convention contained in *flags*. If incoming data represents rows, make *flags* start with **T**\ (op) if first row is y = ymax or **B**\ (ottom) if first row is y = ymin. Then, append **L** or **R** to indicate that first element is at left or right end of row. Likewise for column formats: start with **L** or **R** to position first column, and then append **T** or **B** to position first element in a row. **Note**: These two row/column indicators are only required for grids; for other tables they do not apply. For gridline registered grids: If data are periodic in x but the incoming data do not contain the (redundant) column at x = xmax, append **x**. For data periodic in y without redundant row at y = ymax, append **y**. Append **s**\ *n* to skip the first *n* number of bytes (probably a header). If the byte-order or the words needs to be swapped, append **w**. Select one of several data types (all binary except **a**): - **A** ASCII representation of one or more floating point values per record - **a** ASCII representation of a single item per record - **c** int8_t, signed 1-byte character - **u** uint8_t, unsigned 1-byte character - **h** int16_t, signed 2-byte integer - **H** uint16_t, unsigned 2-byte integer - **i** int32_t, signed 4-byte integer - **I** uint32_t, unsigned 4-byte integer - **l** int64_t, long (8-byte) integer - **L** uint64_t, unsigned long (8-byte) integer - **f** 4-byte floating point single precision - **d** 8-byte floating point double precision [Default format is scanline orientation of ASCII numbers: **La**]. The difference between **A** and **a** is that the latter can decode both *date*\ **T**\ *clock* and *ddd:mm:ss[.xx]* formats but expects each input record to have a single value, while the former can handle multiple values per record but can only parse regular floating point values. Translate incoming *z*-values via the ``incols`` parameter. {b} {d} {e} {f} {h} {i} {r} {w} Returns ------- ret: xarray.DataArray or None Return type depends on whether the ``outgrid`` parameter is set: - :class:`xarray.DataArray`: if ``outgrid`` is not set - None if ``outgrid`` is set (grid output will be stored in file set by ``outgrid``) Example ------- >>> import numpy as np >>> import pygmt >>> # generate a grid for z=x**2+y**2, with an x-range of 0 to 3, >>> # and a y-range of 10.5 to 12.5. The x- and y-spacing are 1.0 and 0.5. >>> x, y = np.meshgrid([0, 1, 2, 3], [10.5, 11.0, 11.5, 12.0, 12.5]) >>> z = x**2 + y**2 >>> xx, yy, zz = x.flatten(), y.flatten(), z.flatten() >>> grid = pygmt.xyz2grd( ... x=xx, y=yy, z=zz, spacing=(1.0, 0.5), region=[0, 3, 10, 13] ... ) """ if "I" not in kwargs or "R" not in kwargs: raise GMTInvalidInput("Both 'region' and 'spacing' must be specified.") with GMTTempFile(suffix=".nc") as tmpfile: with Session() as lib: file_context = lib.virtualfile_from_data( check_kind="vector", data=data, x=x, y=y, z=z, required_z=True ) with file_context as infile: if "G" not in kwargs: # if outgrid is unset, output to tempfile kwargs.update({"G": tmpfile.name}) outgrid = kwargs["G"] lib.call_module("xyz2grd", build_arg_string(kwargs, infile=infile)) return load_dataarray(outgrid) if outgrid == tmpfile.name else None