geeViz.phEEnoViz

Visualize the spectral seasonality of an area to facilitate composting methods development

geeViz.phEEnoViz facilitates the creation of plots to show the seasonality of an area. This is a good tool for deciding what date ranges to use for compositing.

Functions

chartTimeSeriesDistributions(tables, ...[, ...])

Plots time series histograms for each date in the given tables.

check_dir(dir)

Ensures that a directory exists, creating it if necessary.

convert_to_csv(output_table_name)

Converts a JSON GEE table into CSV files, one per band.

getTableWrapper(image, fc, outputName[, ...])

Extracts a JSON table of zonal statistics from an image and exports it.

getTimeSeriesSample(startYear, endYear, ...)

Samples locations for a given area and exports time series data.

limitThreads(limit)

Limits the number of active threads to a specified limit.
geeViz.phEEnoViz.check_dir(dir)[source]

Ensures that a directory exists, creating it if necessary.

Parameters:

dir (str) – The directory path.

Example

>>> check_dir('/tmp/mydir')
geeViz.phEEnoViz.limitThreads(limit)[source]

Limits the number of active threads to a specified limit.

Parameters:

limit (int) – The maximum number of threads allowed.

Example

>>> limitThreads(2)
geeViz.phEEnoViz.getTableWrapper(image, fc, outputName, reducer=<ee.reducer.Reducer object>, scale=30, crs='EPSG:4326', transform=None, tryNumber=1, maxTries=15)[source]

Extracts a JSON table of zonal statistics from an image and exports it.

Parameters:

  • image (ee.Image) – The image to reduce.

  • fc (ee.FeatureCollection) – The feature collection for zonal stats.

  • outputName (str) – Output filename for the JSON table.

  • reducer (ee.Reducer, optional) – Reducer to use. Defaults to ee.Reducer.first().

  • scale (int, optional) – Scale in meters. Defaults to 30.

  • crs (str, optional) – Coordinate reference system. Defaults to “EPSG:4326”.

  • transform (optional) – Transform parameter. Defaults to None.

  • tryNumber (int, optional) – Current try number. Defaults to 1.

  • maxTries (int, optional) – Maximum number of tries. Defaults to 15.

Example

>>> getTableWrapper(image, fc, 'output.json')
geeViz.phEEnoViz.getTimeSeriesSample(startYear, endYear, startJulian, endJulian, compositePeriod, exportBands, studyArea, nSamples, output_table_name, showGEEViz, maskSnow=False, programs=['Landsat', 'Sentinel2'])[source]

Samples locations for a given area and exports time series data.

Parameters:

  • startYear (int) – Start year.

  • endYear (int) – End year.

  • startJulian (int) – Start Julian day.

  • endJulian (int) – End Julian day.

  • compositePeriod (int) – Composite period in days.

  • exportBands (list) – List of bands to export.

  • studyArea (ee.Geometry or ee.FeatureCollection) – Study area.

  • nSamples (int) – Number of samples.

  • output_table_name (str) – Output table name.

  • showGEEViz (bool) – Whether to show GEEViz visualization.

  • maskSnow (bool, optional) – Whether to mask snow. Defaults to False.

  • programs (list, optional) – List of programs. Defaults to [“Landsat”, “Sentinel2”].

Example

>>> getTimeSeriesSample(2019, 2020, 1, 365, 16, ['NDVI'], studyArea, 100, 'output.json', True)
geeViz.phEEnoViz.convert_to_csv(output_table_name)[source]

Converts a JSON GEE table into CSV files, one per band.

Parameters:

output_table_name (str) – Path to the JSON table.

Example

>>> convert_to_csv('output.json')
geeViz.phEEnoViz.chartTimeSeriesDistributions(tables, output_dir, output_base_name, n_bins=40, min_pctl=0.05, max_pctl=99.95, background_color='#D6D1CA', font_color='#1B1716', overwrite=False, howManyHarmonics=3, showChart=False, annotate_harmonic_peaks=True)[source]

Plots time series histograms for each date in the given tables.

Parameters:

  • tables (list) – List of CSV file paths.

  • output_dir (str) – Output directory for charts.

  • output_base_name (str) – Base name for output charts.

  • n_bins (int, optional) – Number of histogram bins. Defaults to 40.

  • min_pctl (float, optional) – Minimum percentile for value clipping. Defaults to 0.05.

  • max_pctl (float, optional) – Maximum percentile for value clipping. Defaults to 99.95.

  • background_color (str, optional) – Background color for plots. Defaults to “#D6D1CA”.

  • font_color (str, optional) – Font color for plots. Defaults to “#1B1716”.

  • overwrite (bool, optional) – Overwrite existing charts. Defaults to False.

  • howManyHarmonics (int, optional) – Number of harmonics for regression. Defaults to 3.

  • showChart (bool, optional) – Show chart interactively. Defaults to False.

  • annotate_harmonic_peaks (bool, optional) – Annotate harmonic peaks. Defaults to True.

Example

>>> chartTimeSeriesDistributions(['table_NDVI.csv'], './charts', 'study_NDVI')