main.py

import streamlit as st
import pandas as pd
import pydeck as pdk
import numpy as np
# import branca.colormap as cm
from matplotlib import cm
from PIL import Image
import ibis
from ibis import _

image = Image.open('./favicon.png')
st.set_page_config(page_title="GBIF Observations in H3", page_icon=image)
st.header("GBIF Observations in H3", divider="rainbow")

# st.set_page_config(page_title="H3 in Streamlit", layout="wide")

h3_parquet = "https://data.source.coop/cboettig/gbif/gbif_ca_h3.parquet"
#h3_parquet = "/home/rstudio/source.coop/cboettig/obis/obis_h3.parquet"

con = ibis.duckdb.connect(extensions=["spatial"])
obis_h3 = con.read_parquet(h3_parquet)

st.subheader("California total observations")


# ------ Visualisation 1 ---------
def viridis_color(x)  -> str:
    rgb_array = np.round( cm.viridis(x) * 255 ).astype(int).clip(0,255).tolist()
    return rgb_array

@st.cache_resource(ttl="2d")
def get_h3point_df(resolution: float) -> pd.DataFrame:
    column = "h" + str(resolution)
    df = (obis_h3
            .rename(cell = column)
            .cell.value_counts()
            .mutate(v = _.cell_count.log())
            .mutate(normalized_values = _.v / _.v.max())
            .to_pandas()
           )
    df['rgb'] = viridis_color(df.normalized_values)
    return df

@st.cache_resource(ttl="2d")
def get_coverage_layer(df: pd.DataFrame) -> pdk.Layer:
    return pdk.Layer(
        "H3HexagonLayer",
        df,
        get_hexagon="cell",
        filled=True,
        auto_highlight=True,
        get_fill_color="rgb",
        get_elevation="normalized_values",
        elevation_scale=5000,
        elevation_range=[0,1],
        pickable=True,
        extruded=True,
        line_width_min_pixels=1,
    )

min_v_1, max_v_1, v_1, z_1, lon_1, lat_1 = ( 1, 9, 4, 4, -120, 40,)
col1, col2 = st.columns([70, 30])
with col1:
    h3_resolut_1 = st.slider(
        "H3 resolution", min_value=min_v_1, max_value=max_v_1, value=v_1)

with col2:
    levels_option = st.selectbox("Add filters", ("One", "Two", "Three"))

df = get_h3point_df(h3_resolut_1)
layer_coverage_1 = get_coverage_layer(df)

visible_layers_coverage_1 = [layer_coverage_1]
st.pydeck_chart(
    pdk.Deck(map_provider='carto', 
        map_style='light',
        initial_view_state=pdk.ViewState(
            latitude=lat_1, longitude=lon_1, zoom=z_1, height=400
        ),
        tooltip={"html": "<b>ID:</b> {cell_count}", "style": {"color": "white"}},
        layers=visible_layers_coverage_1,
    )
)
# ------ Visualisation 1 End ---------
st.divider()