Gerasimos Katsagannis

Fork of Selecting a Year on a Line Chart

This fork of a line chart example uses d3.v5 to visualize vaccination data over time, with a vertical line marking a selected year. Users can hover over the chart to update the selected year via a mouse interceptor that inverts the x-scale, and a d3.ordinal color scale distinguishes regions. The visualization is rendered with SVG, axes, and line paths using d3.line and curveBasis, with data processed from CSV files.

May 23, 2022

Fork of Selecting a Year on a Line Chart

This visualization shows population trends over time for world regions using a multi-line chart, with a vertical line indicating the currently selected year. Users can hover over the chart to change the selected year, which updates the vertical marker. The chart is built with D3 v5, using `scaleLinear`, `scaleTime`, `d3.line` with `curveBasis` for smoothing, and `d3.nest` to group data by region. A color legend is rendered via a custom `colorLegend` function using `scaleOrdinal`. Population data is loaded from CSV census files and processed through a custom `melt` function.

May 23, 2022

Fork of Vega-Lite API Template

This visualization displays COVID-19 vaccination data, plotting total vaccinations against daily raw vaccination numbers, with points colored by date and sized by daily vaccinations. It uses the Vega-Lite API to construct the chart programmatically, registering with Vega and Vega-Lite, while loading data from a CSV via d3.csv. The visualization reads vaccination records from a Gist-hosted dataset, rendering an interactive scatter plot with tooltips that reveal location information, with custom configuration for axis styling and typography.

Fork of Total Number of Rockets Throughout The Years

This stacked bar chart visualizes the total number of rockets launched each year, with bars segmented by the company’s country of origin. The chart uses a count aggregation on the raw data, which is loaded from a CSV file via `d3.csv`. Built with Vega-Lite API and D3 v5, it renders interactive SVG charts with tooltips, while a custom configuration adjusts axis ticks and label styling for readability.

Fork of Total Number of Rockets Throughout The Years

This bar chart visualizes the total number of rockets launched each year, with bars colored by the rocket company’s country of origin. The visualization uses Vega-Lite 4 and the vega-lite-api to aggregate the data by year and country through a groupby transform with a count aggregate. The tooltip encodes the ISO code and country, while custom axis styling and a dark color scheme improve readability. Data is loaded via d3.csv from a Kaggle-derived GitHub dataset.

Fork of Vega-Lite API Template

This example shows a bar chart of population by country, with bars colored by religion and tooltips displaying population values on hover. The visualization is built using the Vega-Lite API, which registers Vega and Vega-Lite libraries and uses a custom configuration to adjust axis and label styling for readability. Data is loaded asynchronously from a CSV file via `d3.csv`, and the chart is rendered as SVG with an autosized fit to the window. The code also integrates the Vega Tooltip handler for interactive hover details.

Data visualizations

This visualization uses D3 v5 to display cumulative COVID-19 vaccination totals over time for multiple countries, with each country represented by a distinct colored line. The line chart employs a time-based x-axis and a linear y-axis scaled to billions of vaccinations. The code uses `d3.csv`, `scaleTime`, `scaleLinear`, `scaleOrdinal`, `nest`, and `line` with `curveBasis` to render the SVG paths, while a custom color legend function shows the country categories. Data comes from a GitHub-hosted CSV of vaccination records.

Fork of Vega-Lite API Template

This example visualizes COVID-19 vaccination data, plotting total vaccinations against people vaccinated as a scatter plot with tooltips showing location names. Built with the Vega-Lite API and D3.js, it registers Vega and Vega-Lite, loads CSV data via `d3.csv`, and renders an interactive SVG chart that fills the viewport. The visualization applies a custom configuration for axis styling and tooltip formatting, using a dark color scheme for labels and titles.

Fork of Coronavirus Deaths Over Time by Country

This chart shows cumulative COVID-19 deaths over time for multiple countries, with each country represented by a colored line on a log-scaled y-axis. The visualization uses React with D3 v5 methods including `scaleTime`, `scaleLog`, and `line` to render SVG paths. Data comes from the Johns Hopkins Coronavirus Dataset via a CSV file loaded with `d3.csv` and `timeParse`. Each country’s timeseries is drawn as a separate path with randomly generated stroke colors, while gridlines and axis labels are created through reusable `XAxis` and `YAxis` components.

Fork of Fork of Vega-Lite API Template

This example displays a scatter plot of COVID-19 vaccination data, mapping daily vaccinations on the x-axis and total vaccinations on the y-axis. It uses the Vega-Lite API to construct the visualization declaratively, with d3.csv fetching the dataset from a GitHub-hosted CSV file. The code customizes the chart’s appearance through a Vega-Lite config object, adjusting axis styles and label fonts for readability. The visualization renders as an SVG via vega-tooltip for interactive hover details.

Fork of Vega-Lite API Template

This example visualizes the relationship between fuel efficiency (miles per gallon) and horsepower across automobile models, with color mapping to the country of origin and point size encoding vehicle weight, and includes tooltips displaying model names. It uses the Vega-Lite API (vl) to declaratively define the scatter plot specification, with data loaded from the UCI Machine Learning Repository’s Auto MPG dataset via d3.csv. The visualization is rendered through Vega’s and Vega-Lite’s JavaScript libraries, integrating the Vega Tooltip for interactive hover details, and applies a custom configuration for axis and label styling.

Fork of Cars Scatter Plot

This scatter plot visualizes the relationship between horsepower and weight for cars from the Auto MPG dataset, with each red circle representing a vehicle. The chart uses D3 v5’s `scaleLinear`, `axisLeft`, and `axisBottom` to construct axes, while circles are appended via `selectAll` and `enter`. Data is loaded as CSV and parsed with numeric conversions. The SVG rendering includes custom axis labels and a title, styled through CSS with opacity and tick formatting.

Fork of Line Chart with Multiple Lines

This line chart displays one week of temperature data for cities around the world, sourced from the Data Canvas - Sense Your City initiative. Each colored line represents a city, with dots marking individual readings and a color legend identifying each series. The visualization uses D3 v5 APIs including `scaleTime`, `scaleLinear`, `scaleOrdinal`, `nest`, `curveBasis`, and `axisLeft`/`axisBottom` to render the SVG. Data is loaded via `csv` and processed from a linked GitHub dataset, while custom axes, gridlines, and a title are generated programmatically.

Fork of Selecting a Year on a Line Chart

This interactive line chart visualizes population changes over time for world regions, with a vertical line marking a user-selected year. Clicking or hovering along the chart updates the selected year, repositioning the line to show the population at that moment. The visualization uses d3.nest and d3.scaleOrdinal to group data by region, d3.line with curveBasis to draw smoothed paths, and d3.axisBottom and d3.axisLeft for labeled axes. Data comes from UN population estimates and projections split across two CSV files, loaded via d3.csv.

Fork of Vega-Lite API Template

This example visualizes global COVID-19 vaccination progress, plotting total vaccinations over time and colored by vaccine type, with tooltips revealing country ISO codes. Built using the Vega-Lite API for D3, the code registers Vega-Lite specifications with `vl.markPoint` and encodes the data through `vl.encode`. The visualization loads CSV data via `d3.csv`, applies a custom configuration for axis styling, and renders to an SVG canvas with interactive tooltips handled by the `vega-tooltip` `Handler`.

May 17, 2022

Fork of Loading and Parsing CSV Data

This example displays the size and structure of a COVID-19 World Vaccination Progress CSV dataset by rendering the file size in kilobytes, row count, and column count in large text. It uses the D3.js library’s `d3.csv` method to fetch and parse the remote CSV file, then accesses the resulting parsed data’s `columns` property to determine the number of columns. The visualization demonstrates a straightforward data-loading workflow, showing the parsed dataset’s basic metadata rather than plotting the actual values. The code also includes commented-out alternatives using `fetch`, `async`/`await`, and `d3.csvParse`.

May 17, 2022