Holoviews datetime. WebGL is standardized and available in all modern browsers.

Holoviews datetime My data (pandas dataframe) has categoricals (on y) and datetime (on x). cftime_to_timestamp(date, time_unit='us') [source] # Converts cftime to timestamp since epoch in milliseconds Non-standard calendars (e. How do I set up the hv. datashader import datashade, rasterize from holoviews import opts, dim import holoviews. NdOverlay plot to show a legend which shows the two groups? What I tried is to generate a curve_dict and then executing hv. HoloViews supports a wide range of data sources including Pandas, Dask, XArray Rapids cuDF, Streamz, Intake, Geopandas, NetworkX and Ibis. Here is the code I am using: import pandas as pd import numpy as np import panel as pn Oct 5, 2022 · The DateSlider widget allows selecting selecting a date value within a set bounds using a slider. Sep 29, 2025 · To learn how to use HoloViews, we recommend that people start with the Getting Started guide, and then use the online help features from within IPython Notebook to learn more. allows Jun 19, 2020 · Hi, I tried to make a quadmesh with the plotly backend, but the datetime values get converted to numerical. The Curve objects belong to a group (in this case either group ‘A’ or group ‘B’). The plots are usually more involved than in the minimal example below, and take data from the row in question into account. When I visualize the rasterized quadmesh without a datetime x-axis, it works fine. WebGL Rendering # WebGL is a JavaScript API that allows rendering content in the browser using hardware acceleration from a Graphics Processing Unit (GPU). DatePicker(name='Date Picker') date_picker Date Picker DatePicker. Nov 10, 2025 · There are four main types of axes supported across plotting backends, standard linear axes, log axes, datetime axes and categorical axes. The plot results in an x-axis looking like this: How can I change the format of the tick labels so that only the hour is showing? I found several examples using the bokeh backend but not much using the matplotlib backend. Dec 11, 2023 · Hi, I’m trying to build an app that lets my users inspect timeseries of data points in a table. 2 This is definitely a bug in holoviews, we just have to add pd. Note that a HeatMap allows mixtures of categorical, numeric and datetime values along the x- and y-axes: Jun 17, 2019 · Hi, I have a pd. 22. This can cause extra space to be added for dates that don’t exist in the original calendar. pandas import panel as pn pn. I'm trying to generate a histogram using the Holoview Histogram function: Jun 10, 2020 · I’m trying to create a dashboard with some settings on the left and a plot layout with two subplots in one column. To reveal the values of a HeatMap we can either enable a colorbar or use the hover tool. VLines(xs). Nov 10, 2025 · To reveal the values of a HeatMap we can either enable a colorbar or add a hover tool. xs=np. 12 bokeh 3. extension… Module contents # HoloViews makes data analysis and visualization simple # HoloViews lets you focus on what you are trying to explore and convey, not on the process of plotting. hv. normal(size=10)hv. save. The resources to get me started is Working with Streaming Data — HoloViews v1. Let’s go ahead and plot this data using various approaches. opts(tools=['hover'],color='red Jun 9, 2020 · So this is an unfortunate quirk of the Bars element in HoloViews which is always categorical and secondarily an issue with categorical axes in bokeh, which do not allow reducing the tick frequency. 22 # Version 1. Another new feature is the addition of sizebar support for Points elements, allowing for better visualization of point sizes in plots. Jun 28, 2021 · I have been trying out the new Holoviews integration with Dash as it finally offers a great native solution to use datashader for some of the plots in my dashboard. 18. To express interactivity entirely using Javascript Apr 28, 2020 · Hello, Im using holoviews in a Bokeh serve to plot a big database, the thing is that the user can filter or even change the database for different variables and plot according to that filter. NdOverlay(curve Nov 10, 2025 · The VLine element is a type of annotation that marks a position along the x-axis. 3. extension ('bokeh') Jul 12, 2020 · Now get data into shape and plot import holoviews as hv import datashader as ds from holoviews. HoloViews is a popular and powerful data visualization library supporting many data and plotting backends. Nov 6, 2023 · My data is an xarray Dataset with dimensions time and z (altitude). Instead of using a method that re-creates the plot and overlays new VLines, every time I change the value for my VLines, I expect streaming to result in better responsiveness. My requirements are The settings should be on the left with a fixed size of 300px. Here is a VLine marking the maximum of a quadratic curve: Nov 10, 2025 · Exporting and Archiving # Most of the other user guides show you how to use HoloViews for interactive, exploratory visualization of your data, while the Applying Customizations user guide shows how to use HoloViews completely non-interactively, generating and rendering images directly to disk using hv. datashader as hd hv. This manual will provide a general Nov 10, 2025 · holoviews. Alternatively you can learn how to build GUIs by declaring parameters independently of any specific widgets in the param user guide. This is a temporary workaround: Aug 29, 2025 · By default ohlc will assume the index OR the first datetime column should be mapped to the x-axis and the first four non-datetime columns correspond to the O (open), H (high), L (low) and C (close) components. This manual will provide a general Aug 3, 2021 · I am simply trying to plot some values against datetime64[ns] timestamps with holoviews. The time dimension is of type numpy. import datetime as dt import numpy as np import pandas as pd We would like to show you a description here but the site won’t allow us. core. categorize_array(array, dim) [source] # Uses a Dimension instance to convert an array of values to categorical (i. . Glad the finalize hook works for you for the time being, but you shouldn't need it! It appears this is related to datetimes with a particular timezone. For this, I would like to use the row_content, because it makes it easy to compare rows that are not neighbors. numeric values use linear/log axes, date (time) values use datetime axes and string or other object types use categorical axes. Dataframe with Timestamp objects as entries for some rows, and would like to display them in timestamp format (eg. After some time I figured out that I can use a function as input to the DynamicMap and not just a HoloViews plot element. This will help us understand the core building blocks of real-time streaming in Panel and HoloViews. responsive horizontally and vertically. How does one update a plot within the main section of a template layout ? Here is a short version To reveal the values of a HeatMap we can enable a colorbar and if you wish to have interactive hover information, you can use the hover tool in the Bokeh backend. Nov 2, 2023 · I’m trying to create a streaming application using HoloViews and the Buffer. hvplot. Also tried bokeh & matplotlib backends, which work fine. I looked at this post from Marc: Panel - starting a stream of data Setting meta_refresh works but is not ideal for my case where the updated plot data comes from a HTTP request. bokeh. line(x='time', y=columnLabels, title='Measurements', xformatter=formatter) hist May 8, 2024 · Hello everyone, I am working on a script that periodically updates and plots a dataset using Holoviews and Panel. Prior to Jan 18, 2025 · 654 questions Newest More Filter 1 vote 0 plotly-dash holoviews datashader Balog Szilárd 61 549 holoviews Caleb 4,167 Dec 18, 2024 at 21:04 Bradley Sutliff geoviews user3750853 holoviews 7,852 Dec 9, 2023 at 13:09 Dec 4, 2023 at 15:19 Jan 13, 2023 · I am trying to update a plot at regular intervals with new data. HoloViews makes it very easy to customize existing plots, or even create completely novel plots. In most cases, this is desirable, but is there a way to revert to the old behavior of showing every label? import xarray as xr import hvplo… Nov 10, 2020 · Hello everybody! I wanted to ask if someone has a solution for this problem: I have a hv. string) values and applies escaping for colons, which bokeh treats as a categorical suffix. Linear axes # Nov 10, 2025 · Working with Plot and Renderers # HoloViews ordinarily hides the plotting machinery from the user. 16) Automatic ranging, aka auto-ranging, on the data in x or y is supported, making it easy to scale the given axes and fit the entire visible curve after a zoom or pan. supports the plotting backends Bokeh (default), Matplotlib and Plotly. We would like to show you a description here but the site won’t allow us. array(df['Datetime'], dtype=np. DynamicMap Oct 5, 2022 · DatePicker uses a browser-dependent calendar widget to select the date: date_picker = pn. Curve objects. When I Nov 10, 2025 · As the above example shows before aggregating the second value for the (0, 0) is ignored unless we aggregate the data first. When I Aug 3, 2021 · I am simply trying to plot some values against datetime64[ns] timestamps with holoviews. Panel, HoloViews, hvPlot and GeoViews are all members of the HoloViz ecosystem and you can expect them to work perfectly together. This allows for very quick iteration over different visualizations to explore a dataset, however it is often important to customize the precise details of a plot. The hover tools even allows displaying any number of additional value dimensions, providing additional information a static plot could not capture. g. ohlc without missing-date gaps wanted to fix Hover (add Date in the right format, and add Volume info) packages: python 3. Not streaming data record by record but a new dataset. dtypes. datetime64) Nov 20, 2024 · 👉 Recommended Workflow (Start Here) # The recommended multichannel timeseries notebook provides a workflow for processing and analyzing multichannel timeseries datasets that fit in memory. Jan 31, 2021 · When I make a plot with a hover tool for several layers, I would like to change the tooltip in the toolbar from the default “Hover” to a custom label when I hover over the hovertool itself in the toolbar. The upper price plot should be a Curve plot. Table automatically reco Aug 18, 2023 · Hey there, on an attempt to create a responsive plot with two VLine elements, I’ve discovered the option to use streams. I want to display rolling values etc. formatters import DatetimeTickFormatter import panel as pn hv. hvPlot (quick viz) and GeoViews (spatial viz) are built on top of HoloViews and produces HoloViews objects. Dec 7, 2022 · Changing the internal storage of holes within HoloViews is unlikely, so after discussing with @Hoxbro we think the best approach in the short term is to explicitly document what is and isn't supported here for filled polygons, and detect what isn't and raise a sensible exception to inform the user. models. It covers the importance of live downsampling using algorithms that maintain the signal shape and optimize browser performance. In this reference notebook we will assume a basic Jun 28, 2021 · I have been trying out the new Holoviews integration with Dash as it finally offers a great native solution to use datashader for some of the plots in my dashboard. Note that a HeatMap allows mixtures of categorical, numeric and datetime values along the x- and y-axes: One of the major design principles of HoloViews is that the declaration of data is completely independent from the plotting implementation. util. By combining the ease of generating interactive, high-dimensional visualizations with the Apr 10, 2017 · It's pretty typical last mile issue with holoviews: when you get your plot defined properly up to 95% but the last 5% makes you drop it and move to native bokeh, matplotlib struggling. DynamicMap Aug 18, 2023 · Hey there, on an attempt to create a responsive plot with two VLine elements, I’ve discovered the option to use streams. WebGL is standardized and available in all modern browsers. Something similar to the third code cell on this page: https://d Dec 6, 2024 · Minimal Example: Streaming Random Data # Before diving into the development of a more advanced streaming application, let’s start with a minimal example using random data. However, while exploring streaming for my use case, I fail to correctly create a hv. 0 where the Buffer is described. It accepts a list of x-coordinates and will draw a vertical line at each location. random. Oct 18, 2019 · How to visualize time span with holoviews? I recently came across holoviews as promising visualization library in python and - as a practice - I wanted to transfer some of my existing code to see how it looks like in hv. In this notebook, we show how HoloViews works together with the Jupyter Notebook to Mar 23, 2025 · mayonnaisecolouredbenz7 changed the title Holoviews panels and axis sharing after plot update Holoviews panels and axis sharing after plot update - datetime axis 3 weeks ago Contributor Author I have a data frame with a datetime index. Date formatting should happen automatically for appropriate date types so we'll need to investigate. plotting. 0 # November 10, 2025 This release adds Narwhals support for broader dataframe compatibility. operation. Is that possibl… Jul 9, 2019 · I'm trying to plot a simple heatmap using bokeh/holoviews. Julian or no leap calendars) are converted to standard Gregorian calendar. Try zooming in on the plot and panning around, the y range nicely adapt to fit the curve. Also strongly recommend using tuples for xlim although a list will probably also work (edited @jbednar ’s reply to reflect that). '2019-04-01') rather than as integers. However, one issue I haven’t found a solution to (despite much googling) is the problem with datetime axes, particularly for Quadmeshes. When I I have a data frame with a datetime index. That is, x-axis = nx1 datetime64[ns] values y-axis = nx1 data. datetime64 [ns]. The problem is that the number of categorical elements is >3000 an Jun 25, 2025 · The VLines element is a type of annotation that can mark multiple lines along the x-axis. Feb 6, 2021 · Strongly recommend using either the DataFrame or xlim option if you’re working with hvPlot, always try to minimize the use of HoloViews API where you can. I reached a given plot which I am unable to recreate. This can be useful to get an overview and a detailed view of some data at the same time. NdOverlay plot of multiple holoviews. It should be In most cases HoloViews automatically detects the appropriate axis type to use based on the type of the data, e. Canvas Rendering - Prior Default # Rendering Bokeh plots in hvPlot or HoloViews has evolved significantly. DatetimeTZDtypeType to the list of recognized datetime_types. This has the advantage over VLine of being able to draw multiple lines at once and also being able to get hover information for each of the line. Along with these new features, this release includes numerous Jun 6, 2018 · import holoviews as hv import pandas as pd import datetime as dt from bokeh. Although it features the MNE-Python library for handling and visualization Jun 14, 2022 · Is it possible to create a reference line on a date axis? The below seems to fail for me: from datetime import datetime import pandas as pd import holoviews as hv import hvplot. By doing so, we now also support Polars and DuckDB data backends. Dec 10, 2019 · I am new to holoviews and bokeh and I am trying to create a scatter plot from a time series where the colors are based on the dates. All I can suggest for the time being is to make use of the Histogram element in HoloViews: lines = df_weekly. widgets. This example sets a simple printf style y-formatter and a custom DatetimeTickFormatter x-formatter that sets the date format when in the days range and a context (find more information on datetime tick context in Bokeh’s documentation). The script is designed to allow dynamic selection of the y-axis for the plot. value Dec 9, 2023 · I have an simple example, run in jupyter notebook: hvplot. The lower delta plot should be a Bar chart responsive vertically fixed horizontally at 300px. Note that a HeatMap allows mixtures of categorical, numeric and datetime values along the x- and y-axes: Releases # Version 1. e. For more information about listening to widget events and laying out widgets refer to the widgets user guide. Aug 29, 2025 · Auto-range # (Available with HoloViews >= 1. Then I want to combine with widgets Apr 20, 2020 · After updating to the latest holoviews, the heatmaps now hide some tick labels. Bokeh provides a powerful platform to generate interactive plots using HTML5 canvas and WebGL, and is ideally suited towards interactive exploration of data. However, I am encountering an issue where the axis selection does not respond to changes in the col_selector widget. In order to handle these dates correctly a custom bokeh model with Nov 10, 2025 · This demo demonstrates how to link two timeseries plots using the RangeToolLink along the x-axis. Here is a screen shot of what I have: Screens Jun 25, 2025 · holoviews. extension("bokeh", "matplotlib") dates = np. Declare data # In most cases HoloViews automatically detects the appropriate axis type to use based on the type of the data, e. value returns a datetime type that can be read out or set like other widgets: date_picker. mwxu tskp jqzu pvskv pmhlt xytla teo eejcwh mhj texzt sqpn okhzhmb vgkor vkkk kbzwch