If you do it yourself in straight JS, you'll very quickly start building the common tools of D3: various scaling mechanisms mapping the domain to the pixels, da

If you do it yourself in straight JS, you'll very quickly start building the common tools of D3: various scaling mechanisms mapping the domain to the pixels, data binding against a set of DOM elements, converting an array of data values to the co-ordinates for the d attribute of an SVG path, etc. Somewhere else someone described D3 as a hammer, and that's a good analogy, because if you don't start with a hammer, it's the first tool you'll make for yourself when you need to pound nails.