erddap_optimize.py

import streamlit as st
import altair as alt
import pandas as pd
import erddapy
from vega_datasets import data

# Connect to ERDDAP
st.title('SWOT Prawler Data')
e = erddapy.ERDDAP('http://heron.pmel.noaa.gov:8080/erddap', protocol='tabledap')
e.dataset_id = 'TELON001_PRAWC_N001' # Data Set to Use

@st.cache
def get_dfp():
    # Pull Data from ERDDAP
    dfp = e.to_pandas()
    dfp['time (UTC)'] = pd.to_datetime(dfp['time (UTC)'])
    return dfp

dfp = get_dfp()

# Create a subset of the datas
sub = dfp.loc[:,['time (UTC)', 'SB_Depth', 'SB_Temp', 'SB_Conductivity', 'wetlab_Chlorophyll']]
source = sub
brush = alt.selection(type='interval')

# dropdown to select y-axis
option = st.selectbox(
            'Select a Dataset',
	        ['SB_Temp:Q', 'SB_Conductivity:Q', 'Optode_Dissolved_O2:O', 'wetlab_Chlorophyll:Q']
         )

# top panel to plot the data
c = (alt.Chart(source, title="SWOT Prawler Data")
        .mark_circle(size=30)
        .encode(
            x=alt.X('time (UTC):T', scale=alt.Scale(clamp=True, padding=10)),
            y=alt.Y('SB_Depth:Q',axis=alt.Axis(title='Depth (m)'), scale=alt.Scale(zero=False, padding=5, domain=[500,0])),
            color=alt.condition(brush, option, alt.value('lightgray'))
       )
       .add_selection(brush)
       .properties(width=700, height=300))

# 2nd chart
second = (alt.Chart(source, title="Zoomed in Plot")
            .mark_circle(size=30)
            .encode(
                y=alt.Y('SB_Depth:Q', sort = "descending"),
		        color=alt.Color(option, sort = 'descending', scale=alt.Scale(scheme="redblue")),
                x='time (UTC):T',
		        tooltip=[
            		alt.Tooltip('time (UTC):O', title='Datetime'),
            		alt.Tooltip('SB_Depth:O', title='Depth'),
            		alt.Tooltip(option, title=option)
                ]
            )
            .transform_filter(brush)
            .properties(height=500, width=700)
            .interactive())

c & second