"""
info - Get information about data tables.
"""
import numpy as np
from pygmt.clib import Session
from pygmt.helpers import (
GMTTempFile,
build_arg_string,
fmt_docstring,
kwargs_to_strings,
use_alias,
)
[docs]
@fmt_docstring
@use_alias(
C="per_column",
I="spacing",
T="nearest_multiple",
V="verbose",
a="aspatial",
f="coltypes",
i="incols",
r="registration",
)
@kwargs_to_strings(I="sequence", i="sequence_comma")
def info(data, **kwargs):
r"""
Get information about data tables.
Reads from files and finds the extreme values in each of the columns
reported as min/max pairs. 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 two columns rounded up and down to the nearest
multiple of the supplied increments given by ``spacing``. Such output will
be in a numpy.ndarray form [*w*, *e*, *s*, *n*], which can be used
directly as the ``region`` parameter for other modules (hence only *dx*
and *dy* are needed). If the ``per_column`` parameter is combined with
``spacing``, then the numpy.ndarray output will be rounded up/down for as
many columns as there are increments provided in ``spacing``. A similar
parameter ``nearest_multiple`` will provide a numpy.ndarray in the form
of [*zmin*, *zmax*, *dz*] for makecpt.
Full option list at :gmt-docs:`gmtinfo.html`
{aliases}
Parameters
----------
data : str, {table-like}
Pass in either a file name to an ASCII data table, a 1-D/2-D
{table-classes}.
per_column : bool
Report the min/max values per column in separate columns.
spacing : str
[**b**\|\ **p**\|\ **f**\|\ **s**]\ *dx*\[/*dy*\[/*dz*...]].
Compute the min/max values of the first n columns to the nearest
multiple of the provided increments [default is 2 columns]. By default,
output results in the form ``[w, e, s, n]``, unless ``per_column`` is
set in which case we output each min and max value in separate output
columns.
nearest_multiple : str
**dz**\[\ **+c**\ *col*].
Report the min/max of the first (0'th) column to the nearest multiple
of dz and output this in the form ``[zmin, zmax, dz]``.
{verbose}
{aspatial}
{incols}
{coltypes}
{registration}
Returns
-------
output : np.ndarray or str
Return type depends on whether any of the ``per_column``,
``spacing``, or ``nearest_multiple`` parameters are set.
- :class:`numpy.ndarray` if either of the above parameters are used.
- str if none of the above parameters are used.
"""
with Session() as lib:
file_context = lib.virtualfile_from_data(check_kind="vector", data=data)
with GMTTempFile() as tmpfile:
with file_context as fname:
lib.call_module(
module="info",
args=build_arg_string(kwargs, infile=fname, outfile=tmpfile.name),
)
result = tmpfile.read()
if any(kwargs.get(arg) is not None for arg in ["C", "I", "T"]):
# Converts certain output types into a numpy array
# instead of a raw string that is less useful.
if result.startswith(("-R", "-T")): # e.g. -R0/1/2/3 or -T0/9/1
result = result[2:].replace("/", " ")
try:
result = np.loadtxt(result.splitlines())
except ValueError:
# Load non-numerical outputs in str type, e.g. for datetime
result = np.loadtxt(result.splitlines(), dtype="str")
return result