import dask.dataframe as dd import holoviews as hv import numpy as np import pandas as pd import panel as pn import param from holoviews.operation.datashader import dynspread, rasterize from utils import ( DATASETS, DATASHADER_LOGO, DATASHADER_URL, DESCRIPTION, ESA_EASTING, ESA_NORTHING, MAJOR_TOM_LOGO, MAJOR_TOM_LYRICS, MAJOR_TOM_PICTURE, MAJOR_TOM_REF_URL, META_DATA_COLUMNS, PANEL_LOGO, PANEL_URL, get_closest_rows, get_image, get_meta_data, ) class DatasetInput(pn.viewable.Viewer): value = param.Selector(objects=DATASETS, allow_None=False, label="Dataset") data = param.DataFrame(allow_None=False) def __panel__(self): return pn.widgets.RadioButtonGroup.from_param( self.param.value, button_style="outline" ) @pn.depends("value", watch=True, on_init=True) def _update_data(self): self.data = pn.cache(get_meta_data)(dataset=self.value) class MapInput(pn.viewable.Viewer): data = param.DataFrame(allow_refs=True, allow_None=False) data_in_view = param.DataFrame(allow_None=False) data_selected = param.DataFrame(allow_None=False) _plot = param.Parameter(allow_None=False) _pointer_x = param.Parameter(allow_None=False) _pointer_y = param.Parameter(allow_None=False) _range_xy = param.Parameter(allow_None=False) _tap = param.Parameter(allow_None=False) updating = param.Boolean() def __panel__(self): return pn.Column( pn.pane.HoloViews( self._plot, height=550, width=800, loading=self.param.updating ), self._description, ) @param.depends("data", watch=True, on_init=True) def _handle_data_dask_change(self): with self.param.update(updating=True): data_dask = dd.from_pandas(self.data).persist() points = hv.Points( data_dask, kdims=["centre_easting", "centre_northing"], vdims=[] ) rangexy = hv.streams.RangeXY(source=points) tap = hv.streams.Tap(source=points, x=ESA_EASTING, y=ESA_NORTHING) agg = rasterize( points, link_inputs=True, x_sampling=0.0001, y_sampling=0.0001 ) dyn = dynspread(agg) dyn.opts(cmap="kr_r", colorbar=True) pointerx = hv.streams.PointerX(x=ESA_EASTING, source=points) pointery = hv.streams.PointerY(y=ESA_NORTHING, source=points) vline = hv.DynamicMap(lambda x: hv.VLine(x), streams=[pointerx]) hline = hv.DynamicMap(lambda y: hv.HLine(y), streams=[pointery]) tiles = hv.Tiles( "https://tile.openstreetmap.org/{Z}/{X}/{Y}.png", name="OSM" ).opts(xlabel="Longitude", ylabel="Latitude") self.param.update( _plot=tiles * agg * dyn * hline * vline, _pointer_x=pointerx, _pointer_y=pointery, _range_xy=rangexy, _tap=tap, ) update_viewed = pn.bind( self._update_data_in_view, rangexy.param.x_range, rangexy.param.y_range, watch=True, ) update_viewed() update_selected = pn.bind( self._update_data_selected, tap.param.x, tap.param.y, watch=True ) update_selected() def _update_data_in_view(self, x_range, y_range): if not x_range or not y_range: self.data_in_view = self.data return data = self.data data = data[ (data.centre_easting.between(*x_range)) & (data.centre_northing.between(*y_range)) ] self.data_in_view = data.reset_index(drop=True) def _update_data_selected(self, tap_x, tap_y): self.data_selected = get_closest_rows(self.data, tap_x, tap_y) @pn.depends("data_in_view") def _description(self): return f"Rows: {len(self.data_in_view):,}" class ImageInput(pn.viewable.Viewer): data = param.DataFrame(allow_refs=True, allow_None=False) column_name = param.Selector( default="Thumbnail", objects=list(META_DATA_COLUMNS), label="Image Type" ) updating = param.Boolean() meta_data = param.DataFrame() image = param.Parameter() plot = param.Parameter() _timestamp = param.Selector(label="Timestamp", objects=[None]) def __panel__(self): return pn.Column( pn.Row( pn.widgets.RadioButtonGroup.from_param( self.param._timestamp, button_style="outline", align="end", ), pn.widgets.Select.from_param( self.param.column_name, disabled=self.param.updating ), ), pn.Tabs( pn.pane.HoloViews( self.param.plot, loading=self.param.updating, height=800, width=800, name="Interactive Image", ), pn.pane.Image( self.param.image, name="Static Image", loading=self.param.updating, width=800, ), pn.widgets.Tabulator( self.param.meta_data, name="Meta Data", loading=self.param.updating, disabled=True, ), pn.pane.Markdown(self.code, name="Code"), dynamic=True, ), ) @pn.depends("data", watch=True, on_init=True) def _update_timestamp(self): if self.data.empty: default_value = None options = [None] print("empty options") else: options = sorted(self.data["timestamp"].unique()) default_value = options[0] print("options", options) self.param._timestamp.objects = options if not self._timestamp in options: self._timestamp = default_value @property def column(self): return META_DATA_COLUMNS[self.column_name] @pn.depends("_timestamp", "column_name", watch=True, on_init=True) def _update_plot(self): if self.data.empty or not self._timestamp: self.meta_data = self.data.T self.image = None self.plot = hv.RGB(np.array([])) else: with self.param.update(updating=True): row = self.data[self.data.timestamp == self._timestamp].iloc[0] self.meta_data = pd.DataFrame(row) self.image = image = pn.cache(get_image)(row, self.column) image_array = np.array(image) if image_array.ndim == 2: self.plot = hv.Image(image_array).opts( cmap="gray_r", xaxis=None, yaxis=None, colorbar=True ) else: self.plot = hv.RGB(image_array).opts(xaxis=None, yaxis=None) @pn.depends("meta_data", "column_name") def code(self): if self.meta_data.empty: return "" parquet_url = self.meta_data.T["parquet_url"].iloc[0] parquet_row = self.meta_data.T["parquet_row"].iloc[0] return f"""\ ```bash pip install aiohttp fsspec holoviews numpy panel pyarrow requests ``` ```python from io import BytesIO import holoviews as hv import numpy as np import panel as pn import pyarrow.parquet as pq from fsspec.parquet import open_parquet_file from PIL import Image pn.extension() parquet_url = "{parquet_url}" parquet_row = {parquet_row} column = "{self.column}" with open_parquet_file(parquet_url, columns=[column]) as f: with pq.ParquetFile(f) as pf: first_row_group = pf.read_row_group(parquet_row, columns=[column]) stream = BytesIO(first_row_group[column][0].as_py()) image = Image.open(stream) image_array = np.array(image) if image_array.ndim==2: plot = hv.Image(image_array).opts(cmap="gray", colorbar=True) else: plot = hv.RGB(image_array) plot.opts(xaxis=None, yaxis=None) pn.panel(plot).servable() ``` ```bash panel serve app.py --autoreload ``` """ class App(param.Parameterized): sidebar = param.Parameter() main = param.Parameter() def __init__(self, **params): super().__init__(**params) self.sidebar = self._create_sidebar() self.main = pn.FlexBox( pn.Column( pn.Row( pn.indicators.LoadingSpinner(value=True, size=50), "**Loading data...**", ), MAJOR_TOM_LYRICS, ) ) pn.state.onload(self._update_main) def _create_sidebar(self): return pn.Column( pn.pane.Image( MAJOR_TOM_LOGO, link_url=MAJOR_TOM_REF_URL, sizing_mode="stretch_width" ), pn.pane.Image( MAJOR_TOM_PICTURE, link_url=MAJOR_TOM_REF_URL, sizing_mode="stretch_width", ), DESCRIPTION, pn.pane.Image(PANEL_LOGO, link_url=PANEL_URL, width=200, margin=(10, 20)), pn.pane.Image( DATASHADER_LOGO, link_url=DATASHADER_URL, width=200, margin=(10, 20) ), ) def _create_main_content(self): dataset = DatasetInput() map_input = MapInput(data=dataset.param.data) image_input = ImageInput(data=map_input.param.data_selected) return pn.Column(dataset, map_input), image_input def _update_main(self): self.main[:] = list(self._create_main_content())