Ian Johnson is the author of Tributary - an open source live-coding environment designed for prototyping data visualizations with D3. He also co-organizes the SF Bay Area d3 Meetup and makes educational D3 videos.
Bay Area D3 and Tributary
D3 contains helper methods like scale() that will preform mathematical operations on the dataset allowing the data to be scaled into a physical range. For example, taking a dataset consisting of values between 0-3000 and displaying them in a 500 pixel area.