Non-linear quantitative scales are slightly more accurate. [Log tick formatting](https://github.com/d3/d3-scale#log_tickFormat) now assumes a default *count* of ten, not Infinity, if not specified. Log scales with domains that span many powers (such as from 1e+3 to 1e+29) now return only one [tick](https://github.com/d3/d3-scale#log_ticks) per power rather than returning *base* ticks per power.
Sequential scales, [d3.scaleSequential](https://github.com/d3/d3-scale#scaleSequential), are a new class of scales with a fixed output [interpolator](https://github.com/d3/d3-scale#sequential_interpolator) instead of a [range](https://github.com/d3/d3-scale#continuous_range). Typically these scales are used to implement continuous sequential or diverging color schemes. Inspired by Matplotlib’s new [perceptually-motived colormaps](https://bids.github.io/colormap/), 4.0 now features [viridis](https://github.com/d3/d3-scale#interpolateViridis), [inferno](https://github.com/d3/d3-scale#interpolateInferno), [magma](https://github.com/d3/d3-scale#interpolateMagma), [plasma](https://github.com/d3/d3-scale#interpolatePlasma) interpolators for use with sequential scales. In conjunction with 4.0’s new[d3.quantize](https://github.com/d3/d3-interpolate#quantize), these interpolators can also be used with[quantile](https://github.com/d3/d3-scale#quantile-scales), [quantize](https://github.com/d3/d3-scale#quantize-scales) and [threshold](https://github.com/d3/d3-scale#threshold-scales) scales.
Sequential scales, [d3.scaleSequential](https://github.com/d3/d3-scale#scaleSequential), are a new class of scales with a fixed output [interpolator](https://github.com/d3/d3-scale#sequential_interpolator) instead of a [range](https://github.com/d3/d3-scale#continuous_range). Typically these scales are used to implement continuous sequential or diverging color schemes. Inspired by Matplotlib’s new [perceptually-motived colormaps](https://bids.github.io/colormap/), 4.0 now features [viridis](https://github.com/d3/d3-scale#interpolateViridis), [inferno](https://github.com/d3/d3-scale#interpolateInferno), [magma](https://github.com/d3/d3-scale#interpolateMagma), [plasma](https://github.com/d3/d3-scale#interpolatePlasma) interpolators for use with sequential scales. Using[d3.quantize](https://github.com/d3/d3-interpolate#quantize), these interpolators can also be applied to[quantile](https://github.com/d3/d3-scale#quantile-scales), [quantize](https://github.com/d3/d3-scale#quantize-scales) and [threshold](https://github.com/d3/d3-scale#threshold-scales) scales.
4.0 also features several Cubehelix color schemes, including [Dave Green’s default](https://github.com/d3/d3-scale#interpolateCubehelixDefault), and a [cyclical rainbow scheme](https://github.com/d3/d3-scale#interpolateRainbow) inspired by [Matteo Niccoli](https://mycarta.wordpress.com/2013/02/21/perceptual-rainbow-palette-the-method/):
4.0 also features new Cubehelix color schemes, including [Dave Green’s default](https://github.com/d3/d3-scale#interpolateCubehelixDefault) and a [cyclical rainbow](https://github.com/d3/d3-scale#interpolateRainbow) inspired by [Matteo Niccoli](https://mycarta.wordpress.com/2013/02/21/perceptual-rainbow-palette-the-method/):
