Source code for pygmt.modules

"""
Non-plot GMT modules.
"""
import xarray as xr


from .clib import Session
from .helpers import (
    build_arg_string,
    fmt_docstring,
    kwargs_to_strings,
    GMTTempFile,
    use_alias,
    data_kind,
    dummy_context,
)
from .exceptions import GMTInvalidInput


[docs]@fmt_docstring def grdinfo(grid, **kwargs): """ Get information about a grid. Can read the grid from a file or given as an xarray.DataArray grid. Full option list at :gmt-docs:`grdinfo.html` Parameters ---------- grid : str or xarray.DataArray The file name of the input grid or the grid loaded as a DataArray. Returns ------- info : str A string with information about the grid. """ kind = data_kind(grid, None, None) with GMTTempFile() as outfile: with Session() as lib: if kind == "file": file_context = dummy_context(grid) elif kind == "grid": file_context = lib.virtualfile_from_grid(grid) else: raise GMTInvalidInput("Unrecognized data type: {}".format(type(grid))) with file_context as infile: arg_str = " ".join( [infile, build_arg_string(kwargs), "->" + outfile.name] ) lib.call_module("grdinfo", arg_str) result = outfile.read() return result
[docs]@fmt_docstring @use_alias(C="per_column", I="spacing", T="nearest_multiple") def info(fname, **kwargs): """ Get information about data tables. Reads from files and finds the extreme values in each of the columns. It recognizes NaNs and will print warnings if the number of columns vary from record to record. As an option, it will find the extent of the first n columns rounded up and down to the nearest multiple of the supplied increments. By default, this output will be in the form *-Rw/e/s/n*, or the output will be in column form for as many columns as there are increments provided. The *nearest_multiple* option will provide a *-Tzmin/zmax/dz* string for makecpt. Full option list at :gmt-docs:`gmtinfo.html` {aliases} Parameters ---------- fname : str The file name of the input data table file. per_column : bool Report the min/max values per column in separate columns. spacing : str ``'[b|p|f|s]dx[/dy[/dz...]]'``. Report the min/max of the first n columns to the nearest multiple of the provided increments and output results in the form *-Rw/e/s/n* (unless *per_column* is set). nearest_multiple : str ``'dz[+ccol]'`` Report the min/max of the first (0'th) column to the nearest multiple of dz and output this as the string *-Tzmin/zmax/dz*. """ if not isinstance(fname, str): raise GMTInvalidInput("'info' only accepts file names.") with GMTTempFile() as tmpfile: arg_str = " ".join([fname, build_arg_string(kwargs), "->" + tmpfile.name]) with Session() as lib: lib.call_module("info", arg_str) return tmpfile.read()
[docs]@fmt_docstring @use_alias(G="download") def which(fname, **kwargs): """ Find the full path to specified files. Reports the full paths to the files given through *fname*. We look for the file in (1) the current directory, (2) in $GMT_USERDIR (if defined), (3) in $GMT_DATADIR (if defined), or (4) in $GMT_CACHEDIR (if defined). *fname* can also be a downloadable file (either a full URL, a `@file` special file for downloading from the GMT Site Cache, or `@earth_relief_*` topography grids). In these cases, use option *download* to set the desired behavior. If *download* is not used (or False), the file will not be found. Full option list at :gmt-docs:`gmtwhich.html` {aliases} Parameters ---------- fname : str The file name that you want to check. download : bool or str If the file is downloadable and not found, we will try to download the it. Use True or 'l' (default) to download to the current directory. Use 'c' to place in the user cache directory or 'u' user data directory instead. Returns ------- path : str The path of the file, depending on the options used. Raises ------ FileNotFoundError If the file is not found. """ with GMTTempFile() as tmpfile: arg_str = " ".join([fname, build_arg_string(kwargs), "->" + tmpfile.name]) with Session() as lib: lib.call_module("which", arg_str) path = tmpfile.read().strip() if not path: raise FileNotFoundError("File '{}' not found.".format(fname)) return path
[docs]@fmt_docstring @use_alias( G="outgrid", R="region", J="projection", N="extend", S="circ_subregion", Z="z_subregion", ) @kwargs_to_strings(R="sequence") def grdcut(grid, **kwargs): """ Extract subregion from a grid. Produce a new *outgrid* file which is a subregion of *grid*. The subregion is specified with *region*; the specified range must not exceed the range of *grid* (but see *extend*). If in doubt, run :meth:`pygmt.grdinfo` to check range. Alternatively, define the subregion indirectly via a range check on the node values or via distances from a given point. Finally, you can give *projection* for oblique projections to determine the corresponding rectangular *region* setting that will give a grid that fully covers the oblique domain. Full option list at :gmt-docs:`grdcut.html` {aliases} Parameters ---------- grid : str The name of the input grid file. outgrid : str or None The name of the output netCDF file with extension .nc to store the grid in. {J} {R} extend : bool or int or float Allow grid to be extended if new *region* exceeds existing boundaries. Give a value to initialize nodes outside current region. circ_subregion : str ``'lon/lat/radius[unit][+n]'``. Specify an origin (*lon* and *lat*) and *radius*; append a distance *unit* and we determine the corresponding rectangular region so that all grid nodes on or inside the circle are contained in the subset. If **+n** is appended we set all nodes outside the circle to NaN. z_subregion : ``'[min/max][+n|N|r]'``. Determine a new rectangular region so that all nodes outside this region are also outside the given z-range [-inf/+inf]. To indicate no limit on *min* or *max* only, specify a hyphen (-). Normally, any NaNs encountered are simply skipped and not considered in the range-decision. Append **+n** to consider a NaN to be outside the given z-range. This means the new subset will be NaN-free. Alternatively, append **+r** to consider NaNs to be within the data range. In this case we stop shrinking the boundaries once a NaN is found [Default simply skips NaNs when making the range decision]. Finally, if your core subset grid is surrounded by rows and/or columns that are all NaNs, append **+N** to strip off such columns before (optionally) considering the range of the core subset for further reduction of the area. Returns ------- ret: xarray.DataArray or None Return type depends on whether the *outgrid* parameter is set: - xarray.DataArray if *outgrid* is not set - None if *outgrid* is set (grid output will be stored in *outgrid*) """ kind = data_kind(grid) with GMTTempFile(suffix=".nc") as tmpfile: with Session() as lib: if kind == "file": file_context = dummy_context(grid) elif kind == "grid": raise NotImplementedError( "xarray.DataArray is not supported as the input grid yet!" ) # file_context = lib.virtualfile_from_grid(grid) # See https://github.com/GenericMappingTools/gmt/pull/3532 # for a feature request. else: raise GMTInvalidInput("Unrecognized data type: {}".format(type(grid))) with file_context as infile: if "G" not in kwargs.keys(): # if outgrid is unset, output to tempfile kwargs.update({"G": tmpfile.name}) outgrid = kwargs["G"] arg_str = " ".join([infile, build_arg_string(kwargs)]) lib.call_module("grdcut", arg_str) if outgrid == tmpfile.name: # if user did not set outgrid, return DataArray with xr.open_dataarray(outgrid) as dataarray: result = dataarray.load() else: result = None # if user sets an outgrid, return None return result
[docs]class config: # pylint: disable=invalid-name """ Set GMT defaults globally or locally. Change GMT defaults globally:: pygmt.config(PARAMETER=value) Change GMT defaults locally by using it as a context manager:: with pygmt.config(PARAMETER=value): ... Full GMT defaults list at :gmt-docs:`gmt.conf.html` """ def __init__(self, **kwargs): # Save values so that we can revert to their initial values self.old_defaults = {} self.special_params = { "FONT": [ "FONT_ANNOT_PRIMARY", "FONT_ANNOT_SECONDARY", "FONT_HEADING", "FONT_LABEL", "FONT_TAG", "FONT_TITLE", ], "FONT_ANNOT": ["FONT_ANNOT_PRIMARY", "FONT_ANNOT_SECONDARY"], "FORMAT_TIME_MAP": ["FORMAT_TIME_PRIMARY_MAP", "FORMAT_TIME_SECONDARY_MAP"], "MAP_ANNOT_OFFSET": [ "MAP_ANNOT_OFFSET_PRIMARY", "MAP_ANNOT_OFFSET_SECONDARY", ], "MAP_GRID_CROSS_SIZE": [ "MAP_GRID_CROSS_SIZE_PRIMARY", "MAP_GRID_CROSS_SIZE_SECONDARY", ], "MAP_GRID_PEN": ["MAP_GRID_PEN_PRIMARY", "MAP_GRID_PEN_SECONDARY"], "MAP_TICK_LENGTH": ["MAP_TICK_LENGTH_PRIMARY", "MAP_TICK_LENGTH_SECONDARY"], "MAP_TICK_PEN": ["MAP_TICK_PEN_PRIMARY", "MAP_TICK_PEN_SECONDARY"], } with Session() as lib: for key in kwargs: if key in self.special_params: for k in self.special_params[key]: self.old_defaults[k] = lib.get_default(k) else: self.old_defaults[key] = lib.get_default(key) # call gmt set to change GMT defaults arg_str = " ".join( ["{}={}".format(key, value) for key, value in kwargs.items()] ) with Session() as lib: lib.call_module("set", arg_str) def __enter__(self): return self def __exit__(self, exc_type, exc_value, traceback): # revert to initial values arg_str = " ".join( ["{}={}".format(key, value) for key, value in self.old_defaults.items()] ) with Session() as lib: lib.call_module("set", arg_str)