export function scale_pixels_range()

in src/infertypes.ts [100:141]

• 37 lines of code
• 10 McCabe index (conditional complexity)

export function scale_pixels_range(scale: any, extents: [number, number]): ScaleDomainRange {
    /**
     * Converts scale range in pixels back to domain (aka inverts the scale)
     */
    console.assert(scale, "No scale provided to `scale_pixels_range`");
    console.assert(extents, "No extents provided to `scale_pixels_range`", extents);
    const scaleToNorm = d3.scaleLinear().domain(scale.range()).range([0, 1]);
    const normalized = [scaleToNorm(extents[0]), scaleToNorm(extents[1])] as [number, number];
    switch (scale.hip_type as ParamType) {
        case ParamType.CATEGORICAL:
            const domain: Array<string> = scale.domain();
            const firstIdx = Math.ceil(Math.min(normalized[0], normalized[1]) * (domain.length - 1));
            const lastIdx = Math.floor(Math.max(normalized[0], normalized[1]) * (domain.length - 1) + 1);
            return {
                "type": scale.hip_type,
                "brush_extents_normalized": normalized,
                "values": domain.slice(firstIdx, lastIdx),
            };
        case ParamType.NUMERIC:
        case ParamType.NUMERICLOG:
        case ParamType.NUMERICPERCENTILE:
        case ParamType.TIMESTAMP:
            const pxlRange: Array<number> = scale.range();
            // Small hack to make sure we can always select the extrema
            // (considering loss of precision in computations, especially for logscale)
            for (var i = 0; i < 2; ++i) {
                if (extents[i] == Math.min(...pxlRange)) {
                    --extents[i];
                }
                if (extents[i] == Math.max(...pxlRange)) {
                    ++extents[i];
                }
            }
            const range = [scale.invert(extents[0]), scale.invert(extents[1])] as [number, number];
            return {
                "type": scale.hip_type,
                "brush_extents_normalized": normalized,
                "range": range,
                "include_infnans": extents[0] <= scale(Infinity) && scale(Infinity) <= extents[1]
            };
    }
}