Wrapper for gmtselect

[weiji14]

Description of the desired feature

Implement gmtselect which "Select data table subsets based on multiple spatial criteria".

Mentioned at https://twitter.com/ATiredGradStdnt/status/1417189659365498884, also partially used before at https://forum.generic-mapping-tools.org/t/gmt-example-18-with-pygmt-volumes-and-spatial-selections/1585.

This function will probably be named select, i.e. called using pygmt.select(). As a table in, table out function, the implementation would be similar to already wrapped functions like blockmedian/blockmean. The code snippet would look something like so:

pygmt/pygmt/src/blockm.py

Lines 41 to 64 in 31980e8

	with GMTTempFile(suffix=".csv") as tmpfile:
	with Session() as lib:
	# Choose how data will be passed into the module
	table_context = lib.virtualfile_from_data(
	check_kind="vector", data=table, x=x, y=y, z=z
	)
	# Run blockm* on data table
	with table_context as infile:
	if outfile is None:
	outfile = tmpfile.name
	arg_str = " ".join([infile, build_arg_string(kwargs), "->" + outfile])
	lib.call_module(module=block_method, args=arg_str)
	# Read temporary csv output to a pandas table
	if outfile == tmpfile.name: # if user did not set outfile, return pd.DataFrame
	try:
	column_names = table.columns.to_list()
	result = pd.read_csv(tmpfile.name, sep="\t", names=column_names)
	except AttributeError: # 'str' object has no attribute 'columns'
	result = pd.read_csv(tmpfile.name, sep="\t", header=None, comment=">")
	elif outfile != tmpfile.name: # return None if outfile set, output in outfile
	result = None
	return result

Xref table I/O discussion at #1268 and #1318. Best to wrap this module after #1426.

Are you willing to help implement and maintain this feature? Yes

[seisman]

Can we close the issue, since the initial wrapper has been done in #1429? Or do we still want to keep this issue open to tracking missing aliases, and gallery examples? Keeping the issue open makes me think that it has not been wrapped.

Related to #1599.

[weiji14]

Ok, closing as initial implementation done at #1429. Tracking progress on project board https://github.com/GenericMappingTools/pygmt/projects/9#card-72007028 instead.