Configuration

xDEM allows to configure the verbosity level and the default behaviour of certain operations on elevation data (such as resampling method for reprojection, or pixel interpretation) directly at the package level.

Verbosity level

To configure the verbosity level (or logging) for xDEM, you can utilize Python’s built-in logging module. This module has five levels of verbosity that are, in ascending order of severity: DEBUG, INFO, WARNING, ERROR and CRITICAL. Setting a level prints output from that level and all other of higher severity. Logging also allows you to specify other aspects, such as the destination of the output (console, file).

Important

The default verbosity level is WARNING, implying that INFO and DEBUG do not get printed. Use the basic configuration as below to setup an INFO level.

To specify the verbosity level, set up a logging configuration at the start of your script:

import logging

# Basic configuration to simply print info
logging.basicConfig(level=logging.INFO)

Optionally, you can specify the logging date, format, and handlers (destinations).

# More advanced configuration
logging.basicConfig(
    level=logging.INFO,
    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s',
    datefmt='%Y-%m-%d %H:%M:%S',
    handlers=[
        logging.FileHandler('app.log'), # Log messages will be saved to this file
        logging.StreamHandler()         # Log messages will also be printed to the console
    ])

The above configuration will log messages with a severity level of INFO and above, including timestamps, logger names, and log levels in the output. You can change the logging level as needed.

Raster–vector–point operations

To change the configuration at the package level regarding operations for rasters, vectors and points, see GeoUtils’ configuration.

For instance, this allows to define a preferred resampling algorithm used when interpolating and reprojecting (e.g., bilinear, cubic), or the default behaviour linked to pixel interpretation during point–raster comparison. These changes will then apply to all your operations in xDEM, such as coregistration.

Profiling

GeoUtils has a built-in profiling tool to provide more insight on the memory and computing time of a function (see GeoUtils’ profiling for details).

The functions to monitor can be decoratored by profile:

from geoutils.profiler import profile

@profile("my profiled function name", memprof=True, interval=0.5)
def my_xdem_function():
  ...

Some functions are already profiled automatically when the Profiler is enabled, with a memory consumption report each 0.05 seconds. Those are:

• DEM loading through DEM,

• All terrain attributes such as slope(),

• Co-registration through fit_and_apply() and coregister_3d().

Finally, in any other script, the profiler can be activated and the output directory defined:

from geoutils.profiler import Profiler

Profiler.enable(save_graphs=True, save_raw_data=True)

# ...
# Code calling decorated functions, such as terrain attribute
import xdem
dem = xdem.DEM(xdem.examples.get_path("longyearbyen_ref_dem"))
slope = dem.slope()
# ...

# Generate the output summary
my_output_directory="./profile_output/"
Profiler.generate_summary(my_output_directory)