How to connect multiple outputs to callbacks? - python-3.x

I'm trying to create a dashboard with a dropdown menu, with each menu item, when selected, loads 2 figures. I did the following but the output figures are the same no matter what I select in the dropdown. When I selected '3 Day Forward Return', I want it to show fig 11 and fig 12.
app = dash.Dash()
fig_names = ['1 Week Forward Return','3 Day Forward Return', 'Next-Day Forward Return ']
fig_dropdown = html.Div([
dcc.Dropdown(id='fig_dropdown',options=[{'label': x, 'value': x} for x in fig_names])])
fig_plot1 = dcc.Graph(id='macdwkly',figure = fig1, style={'display': 'inline-block'})
fig_plot2 = dcc.Graph(id='rsiwkly',figure = fig2, style={'display': 'inline-block'})
app.layout = html.Div([fig_dropdown, fig_plot1,fig_plot2])
#app.callback(Output('fig_plot', 'children'),
[Input('fig_dropdown', 'value')])
def update_output(fig_name):
return name_to_figure(fig_name)
def name_to_figure(fig_names):
figure = go.Figure()
if fig_name == '1 Week Forward Return':
fig1 = px.scatter(dfx, x=dfx.MACD, y=dfx.Wkly_FR, color=dfx['wkly_gt_0'])
fig2 = px.scatter(dfx, x=dfx.RSI, y=dfx.Wkly_FR, color=dfx['wkly_gt_0'])
elif fig_name == '3 Day Forward Return':
fig11 = px.scatter(dfx, x=dfx.MACD, y=dfx.Three_d_FR, color=dfx['tred_gt_0'])
fig12 = px.scatter(dfx, x=dfx.RSI, y=dfx.Three_d_FR, color=dfx['tred_gt_0'])
return dcc.Graph(figure=figure)
if __name__ == '__main__':
app.run_server()

You should correct Output('fig_plot', 'children') to :
[Output('macdwkly', 'figure'),Output('rsiwkly', 'figure')]
Accordingly, the return of name_to_figure should return two figures:
def name_to_figure(fig_names):
...
...
...
return (fig1 , fig2)
Also rename all variables inside name_to_figure to fig1 and
fig2 inside the if-else statements.
Also correct the variable name fig_name to fig_names inside the
conditions of if-else statements.
No need for go.Figure because you use px.scatter, instead.

Related

scatter plot with Dash

I am coding a Dash page to plot some data for myself.
I want to have some dynamic features on some of my plots.
On my dash I have one dropdown, one pie chart and one scatter chart.
Here is my code:
import dash
import dash_core_components as dcc
import dash_html_components as html
from dash.dependencies import Input, Output
import plotly.graph_objs as go
app = dash.Dash()
app.layout = html.Div([
html.Label(['Select the Type:']),
dcc.Dropdown(
id='type_filter',
options=[{'label': i, 'value': i} for i in df.Type.unique()],
value='All'
),
dcc.Graph(
id='allocation_chart'
),
dcc.Graph(
id='allocation_history_chart'
),
])
#app.callback(
Output('allocation_chart','figure'),
[
Input('type_filter', 'value')
]
)
def update_allocation(type_):
if type_ == 'All':
filtered = df
else:
mask = df['Type'] == type_
filtered = df.loc[mask]
data = [
go.Pie(
labels=filtered['Asset'],
values=filtered['Total']
)
]
return {
'data': data,
'layout': go.Layout(title='Asset Allocation by Type')
}
#app.callback(
Output('allocation_history_chart','figure'),
[
Input('type_filter','value')
]
)
def update_allocation_history(type_):
if type_ == 'All':
filtered = df_index
else:
mask = df['Type'] == type_
filtered = df_index.loc[mask]
data = go.Figure()
for ticker in filtered.index:
data.add_trace(
go.Scatter(
x = filtered.loc[ticker].index,
y = filtered.loc[ticker],
name = ticker
)
)
return {
'data': [data],
'layout': go.Layout(title='History of Asset')
}
if __name__ == '__main__':
app.run_server()
here is the Dash:
Here is the scatter chart ran in my Notebook:
Everything is working - Dash is running well, i can see the dropdown and the pie chart - except the scatter chart - the second one.
I absolutely don't understand why because when I run the scatter chart in my Notebook it's working pretty well.
If you have any idea, don't hesitate.

live data Dash plot with python

i have write a code in python to plot data in realtime. there is only one problem the code run i get no errors but there is also no plot in web page that i created.
can any one help me pleadse?
thanks
ma code
#app work
app = dash.Dash(__name__)
#html layout
app.layout = html.Div(
[
dcc.Graph(id = 'live-graph',
animate = True),
dcc.Interval(
id = 'graph-update',
interval = 1*1000,
n_intervals = 0 ),])
I recommend checking the data in raw[0] and raw1 and I do not think you need list(str()). You need also to bring the data from the database by increasing the value after LIMIT. Therefore, you should let the size of the data coming from the database increase dynamically and being controlled by n_intervals such that select * from ..... LIMIT + n and absolutely the value of n should start from 1, therefore set n_intervals to 1 accordingly. Another error in your program, you return figure which is not graph_object and dbc.Graph expects graph_object.
In the example below, I created a dataframe from CSV file, but you can understand the logic and apply it directly to your example:
from dash import Dash, html, dcc
import plotly.graph_objects as go
from dash.dependencies import Input, Output
import pandas as pd
import numpy
app = Dash(__name__)
df = pd.read_csv("data.csv")
app.layout = html.Div(
[
dcc.Graph(id='live-graph'),
dcc.Interval(
id='interval-component',
interval=1000, # in milliseconds
n_intervals = 1, # start
),
]
)
#app.callback(
Output('live-graph', 'figure'),
[Input('interval-component', 'n_intervals')]
)
def update_graph_scatter(n):
if n <= len(df):
row = df.iloc[:n,:]
w = numpy.asarray(row[df.columns[0]])
volt = numpy.asarray(row[df.columns[1]])
data = go.Scatter( x = w , y = volt , hoverinfo='text+name+y', name='Scatter', mode= 'lines+markers', )
layout = go.Layout(xaxis = dict(range=[min(w),max(w)]), yaxis = dict(range=[min(volt)-1,max(volt)+1]))
figure = go.Figure({'data' :data, 'layout' : layout})
return figure
app.run_server(debug=True, use_reloader=False)

I am trying to create a population pyramid graph using Dash with Plotly

i have a directory containing three files, years.csv, 2014.csv and 2015.csv. i want to plot a population pyramid graph for the two files but i want pandas to pick the dataframe from the years.csv with respect to the slider value.
my years.csv looks like, on the slider when i select 2014, from the code you can see, its an int that i convert into a string and append .csv to it. but all i want is that final string interpreted as df = pd.read_csv('2014.csv') so that i can be able to generate graphs of all the years as long as that file is in the directoy.
years
0
2014(2014.csv)
1
2015(2015.csv)
from dash import Dash, dcc, html, Input, Output
# import plotly.express as px
import plotly.graph_objects as gp
import pandas as pd
# df = pd.read_csv('https://raw.githubusercontent.com/plotly/datasets/master/gapminderDataFiveYear.csv')
df = pd.read_csv('years.csv')
app = Dash(__name__)
app.layout = html.Div([
dcc.Graph(id='graph-with-slider'),
dcc.Slider(
df['year'].min(),
df['year'].max(),
step=None,
value=df['year'].min(),
marks={str(year): str(year) for year in df['year'].unique()},
id='year-slider'
)
])
#app.callback(
Output('graph-with-slider', 'figure'),
Input('year-slider', 'value'))
def update_figure(selected_year):
new_df = str(df[df.year == selected_year]) + ".csv"
print(new_df)
# fig = px.scatter(filtered_df, x="gdpPercap", y="lifeExp",
# size="pop", color="continent", hover_name="country",
# log_x=True, size_max=55)
y_age = new_df['Age']
x_M = new_df['Male']
x_F = new_df['Female'] * -1
# fig.update_layout(transition_duration=500)
# Creating instance of the figure
fig = gp.Figure()
# Adding Male data to the figure
fig.add_trace(gp.Bar(y= y_age, x = x_M,
name = 'Male',
orientation = 'h'))
# Adding Female data to the figure
fig.add_trace(gp.Bar(y = y_age, x = x_F,
name = 'Female', orientation = 'h'))
# Updating the layoutout for our graph
fig.update_layout(title = 'Population Pyramid of Uganda-2015',
title_font_size = 22, barmode = 'relative',
bargap = 0.0, bargroupgap = 0,
xaxis = dict(tickvals = [-600000, -400000, -200000,
0, 200000, 400000, 600000],
ticktext = ['6k', '4k', '2k', '0',
'2k', '4k', '6k'],
title = 'Population in Thousands',
title_font_size = 14)
)
# fig.show()
return fig
if __name__ == '__main__':
app.run_server(debug=True)

Plotly Dash Graph With Multiple Dropdown Inputs Not Working

I’m trying to create a time-series Dash line graph that has multiple interactive dropdown user input variables. I would ideally like each of the dropdown inputs to allow for multiple selections.
While I’m able to create the drop down menus successfully, the chart isn’t updating like I’d like. When I allow the dropdowns to have multiple selections, I get an error that arrays are different lengths. And when I limit the dropdowns to one selection, I get an error that [‘Vendor_Name’] is not in index. So this may be two separate problems.
Graph that doesn’t work:
Snippet of Excel data imported into DF
import dash
import dash_core_components as dcc
import dash_html_components as html
from dash.dependencies import Input, Output
import pandas as pd
#import plotly.graph_objs as go
df = pd.read_csv("Data.csv", sep = "\t")
df['YearMonth'] = pd.to_datetime(df['YearMonth'], format = '%Y-%m')
cols = ['Product_1', 'Product_2', 'Product_3']
vendor = df['Vendor'].unique()
app = dash.Dash('Data')
app.layout = html.Div([
html.Div([
html.Div([
html.Label('Product'),
dcc.Dropdown(
id = 'product',
options = [{
'label' : i,
'value' : i
} for i in cols],
multi = True,
value = 'Product_1'
),
]),
html.Div([
html.Label('Vendor'),
dcc.Dropdown(
id = 'vendor',
options = [{
'label' : i,
'value' : i
} for i in vendor],
multi = True,
value = 'ABC')
,
]),
]),
dcc.Graph(id = 'feature-graphic')
])
#app.callback(Output('feature-graphic', 'figure'),
[Input('product', 'value'),
Input('vendor', 'value')])
def update_graph(input_vendor, input_column):
df_filtered = df[df['Vendor'] == input_vendor]
##also tried setting an index because of the error I was getting. Not sure if necessary
df_filtered = df_filtered.set_index(['Vendor'])
traces = []
df_by_col = df_filtered[[input_column, 'YearMonth']]
traces.append({
'x' :pd.Series(df_by_col['YearMonth']),
'y' : df_by_col[input_column],
'mode' : 'lines',
'type' : 'scatter',
'name' :'XYZ'}
)
fig = {
'data': traces,
'layout': {'title': 'Title of Chart'}
}
return fig
if __name__ == '__main__':
app.run_server(debug=False)
Thanks in advance for helping! Still new-ish to Python, but very excited about Dash’s capabilities. I’ve been able to create other graphs with single inputs, and have read through documentation.
Here is the approach I followed: (editing common example available in google with my approach):
import dash
from dash.dependencies import Input, Output
import dash_core_components as dcc
import dash_html_components as html
app = dash.Dash(__name__)
all_options = {
'America': ['New York City', 'San Francisco', 'Cincinnati'],
'Canada': [u'Montréal', 'Toronto', 'Ottawa']
}
app.layout = html.Div([
dcc.Dropdown(
id='countries-dropdown',
options=[{'label': k, 'value': k} for k in all_options.keys()],
value='America', #default value to show
multi=True,
searchable=False
),
dcc.Dropdown(id='cities-dropdown', multi=True, searchable=False, placeholder="Select a city"),
html.Div(id='display-selected-values')
])
#app.callback(
dash.dependencies.Output('cities-dropdown', 'options'),
[dash.dependencies.Input('countries-dropdown', 'value')])
def set_cities_options(selected_country):
if type(selected_country) == 'str':
return [{'label': i, 'value': i} for i in all_options[selected_country]]
else:
return [{'label': i, 'value': i} for country in selected_country for i in all_options[country]]
if __name__ == '__main__':
app.run_server(debug=True)
Workaround here is: When there is single input present in parent dropdown, the value is in string format. But for multiple values, it comes in list format.
This code also work perfectly and gets updated automatically even when you click on cross option to remove any selected option.
Note: I have used 'placeholder' attribute instead of defining default value for it as it made no sense in this case. But you can also update the value dynamically in similar way.
1 input data
The data as it is in the csv is hard to loop.
And I would argue that it is the main reason your code does not work,
because you seem to understand the fundamental code structure.
Having put on my SQL glasses I think you should try to get it to sth like
Date, Vendor, ProductName, Value
2 callback input types change
multi is tricky because it changes switches between returning a str if only 1 item is selected and list if more than one is selected
3 callback return type
you code returns a dict but the callback declared figure as the return type
but here is the code with debugging traces of print() and sleep()
import pandas as pd
import dash
import dash_core_components as dcc
import dash_html_components as html
from dash.dependencies import Input, Output
import plotly.graph_objs as go
import time
df = pd.read_csv("Data.csv", sep="\t")
df['YearMonth'] = pd.to_datetime(df['YearMonth'], format='%Y-%m')
products = ['Product_1', 'Product_2', 'Product_3']
vendors = df['Vendor'].unique()
app = dash.Dash('Data')
app.layout = html.Div([
html.Div([
html.Div([
html.Label('Product'),
dcc.Dropdown(
id='product',
options=[{'label' : p, 'value' : p} for p in products],
multi=True,
value='Product_1'
),
]),
html.Div([
html.Label('Vendor'),
dcc.Dropdown(
id='vendor',
options=[{'label': v, 'value': v} for v in vendors],
multi=True,
value='ABC'
),
]),
]),
dcc.Graph(id='feature-graphic', figure=go.Figure())
])
#app.callback(
Output('feature-graphic', 'figure'),
[Input('product', 'value'),
Input('vendor', 'value')])
def update_graph(input_product, input_vendor):
# df_filtered[['Product_1', 'YearMonth']]
if type(input_product) == str:
input_product = [input_product]
if type(input_vendor) == str:
input_vendor= [input_vendor]
datasets = ['']
i = 1
for vendor in input_vendor:
df_filtered = df[df['Vendor'] == vendor]
for product in input_product:
datasets.append((df_filtered[['YearMonth', 'Vendor', product]]).copy())
datasets[i]['ProductName'] = product
datasets[i].rename(columns={product: 'Value'}, inplace=True)
i += 1
datasets.pop(0)
print(datasets)
traces = ['']
for dataset in datasets:
print(dataset)
time.sleep(1)
traces.append(
go.Scatter({
'x': dataset['YearMonth'],
'y': dataset['Value'],
'mode': 'lines',
'name': f"Vendor: {dataset['Vendor'].iloc[0]} Product: {dataset['ProductName'].iloc[0]}"
}))
traces.pop(0)
layout = {'title': 'Title of Chart'}
fig = {'data': traces, 'layout': go.Layout(layout)}
return go.Figure(fig)
if __name__ == '__main__':
app.run_server()
quick and dirty disclosure:
If you handle the 1. issue it will dramatically simplify everything.
So I'd try to isolate the pd.DataFrame() juggling out of the callback and into the upper I/O part.
1) don't use counters in for loops
2) my variable names aren't the best either
3) the following style is caveman's python and there must be a better way:
traces = ['']
traces.append(this_and_that)
traces.pop(0)
Generally:
using print(input_variable) and print(type(input_variable))
gets my wheels most of the time out of the mud.
after all
you should notice that each trace got its individual name which will show up in the legend. Clicking on the name in the legend will add or remove the trace without the need for#app.callback()

How to use a slider callback to filter a ColumnDataSource in Bokeh using Python 3?

I'm trying to use a slider with a callback in Bokeh using Python 3 to filter the rows of my ColumnDataSource objects (which originate from a DataFrame). More specifically, if a slider with options of 0 to 10000000 (in multiples of 1 million) returns a value N of say 2000000, then I want my plot to only show the data for, in this case, US counties where the population is >= 2000000. Below is my code. Everything works as I want it to except for the slider callback.
from bokeh.io import curdoc
from bokeh.layouts import layout
from bokeh.models import HoverTool, ColumnDataSource, Select, Slider
from bokeh.plotting import figure
TOOLS='pan,wheel_zoom,box_zoom,reset,tap,save,box_select,lasso_select'
source1 = ColumnDataSource(df[df.winner == 'Democratic'])
source2 = ColumnDataSource(df[df.winner == 'Republican'])
hover = HoverTool(
tooltips = [
('County Name', '#county'),
('Population', '#population'),
('Land Area', '#land_area'),
('Pop. Density', '#density'),
('Winning Party', '#winner'),
('Winning Vote %', '#winning_vote_pct'),
]
)
# Plot
plot = figure(plot_width=800, plot_height=450, tools=[hover, TOOLS],
title='2016 US Presidential Vote % vs. Population Density (by County)',
x_axis_label='Vote %', y_axis_label='Population Density (K / sq. mi.)')
y = 'density'
size = 'bokeh_size'
alpha = 0.5
c1 = plot.circle(x='pct_d', y=y, size=size, alpha=alpha, color='blue',
legend='Democratic-Won County', source=source1)
c2 = plot.circle(x='pct_r', y=y, size=size, alpha=alpha, color='red',
legend='Republican-Won County', source=source2)
plot.legend.location = 'top_left'
# Select widget
party_options = ['Show both parties', 'Democratic-won only', 'Republican-won only']
menu = Select(options=party_options, value='Show both parties')
# Slider widget
N = 2000000
slider = Slider(start=0, end=10000000, step=1000000, value=N, title='Population Cutoff')
# Select callback
def select_callback(attr, old, new):
if menu.value == 'Democratic-won only': c1.visible=True; c2.visible=False
elif menu.value == 'Republican-won only': c1.visible=False; c2.visible=True
elif menu.value == 'Show both parties': c1.visible=True; c2.visible=True
menu.on_change('value', select_callback)
# Slider callback
def slider_callback(attr, old, new):
N = slider.value
# NEED HELP HERE...
source1 = ColumnDataSource(df.loc[(df.winner == 'Democratic') & (df.population >= N)])
source2 = ColumnDataSource(df.loc[(df.winner == 'Republican') & (df.population >= N)])
slider.on_change('value', slider_callback)
# Arrange plots and widgets in layouts
layout = layout([menu, slider],
[plot])
curdoc().add_root(layout)
Here is a solution using CustomJSFilter and CDSView as suggest in the other answer by Alex. It does not directly use the data as supplied in the question, but is rather a general hint how this can be implemented:
from bokeh.layouts import column
from bokeh.models import CustomJS, ColumnDataSource, Slider, CustomJSFilter, CDSView
from bokeh.plotting import Figure, show
import numpy as np
# Create some data to display
x = np.arange(200)
y = np.random.random(size=200)
source = ColumnDataSource(data=dict(x=x, y=y))
plot = Figure(plot_width=400, plot_height=400)
# Create the slider that modifies the filtered indices
# I am just creating one that shows 0 to 100% of the existing data rows
slider = Slider(start=0., end=1., value=1., step=.01, title="Percentage")
# This callback is crucial, otherwise the filter will not be triggered when the slider changes
callback = CustomJS(args=dict(source=source), code="""
source.change.emit();
""")
slider.js_on_change('value', callback)
# Define the custom filter to return the indices from 0 to the desired percentage of total data rows. You could also compare against values in source.data
js_filter = CustomJSFilter(args=dict(slider=slider, source=source), code=f"""
desiredElementCount = slider.value * 200;
return [...Array(desiredElementCount).keys()];
""")
# Use the filter in a view
view = CDSView(source=source, filters=[js_filter])
plot.line('x', 'y', source=source, line_width=3, line_alpha=0.6, view=view)
layout = column(slider, plot)
show(layout)
I hope this helps anyone who stumbles upon this in the future! Tested in bokeh 1.0.2
A quick solution with minimal change to your code would be:
def slider_callback(attr, old, new):
N = new # this works also with slider.value but new is more explicit
new1 = ColumnDataSource(df.loc[(df.winner == 'Democratic') & (df.population >= N)])
new2 = ColumnDataSource(df.loc[(df.winner == 'Republican') & (df.population >= N)])
source1.data = new1.data
source2.data = new2.data
When updating data sources, you should replace the data, not the whole object. Here I still create new ColumnDataSource as shortcut. A more direct way (but more verbose too) would be to create the dictionary from the filtered df's columns:
new1 = {
'winner': filtered_df.winner.values,
'pct_d': filtered_df.pct_d.values,
...
}
new2 = {...}
source1.data = new1
source2.data = new2
Note that there's another solution which would make the callback local (not server based) by using a CDSView with a CustomJSFilter. You can also write the other callback with a CDSView as well make the plot completely server-independent.

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