function periodLinearScale()

in widgets/agile-charts/src/app/chart-presentation-model.js [143:203]

• 39 lines of code
• 6 McCabe index (conditional complexity)

    function periodLinearScale(initialDomain, initialRange) {
      let domain = initialDomain;
      let range = initialRange;
      let output;
      let input;

      function linear(uninterpolate, interpolate) {
        const u = uninterpolate(domain[0], domain[1]);
        const i = interpolate(range[0], range[1]);
        return x => i(u(x));
      }

      function uninterpolateNumber(a, b) {
        // eslint-disable-next-line no-param-reassign
        return x => ((x - a) * (b - (a = +a) ? 1 / (b - a) : 0));
      }

      function rescale() {
        output = linear(uninterpolateNumber, d3.interpolateNumber);
        input = linear(uninterpolateNumber, d3.interpolateNumber);
        return scale;
      }

      function scale(x) {
        return output(x);
      }

      scale.invert = y => input(y);
      scale.domain = x => {
        if (!x) {
          return domain;
        }
        domain = x.map(Number);
        return rescale();
      };
      scale.range = x => {
        if (!x) {
          return range;
        }
        range = x;
        return rescale();
      };
      scale.ticks = m => {
        const start = domain[0];
        const stop = domain[1];
        const extent = start < stop ? [start, stop] : [stop, start];
        const minInHour = 60;
        const defaultM = 10;
        const scaledMinutes = Math.floor(
          (extent[1] - extent[0]) / (m || defaultM)
        );
        const hours = Math.floor(scaledMinutes / minInHour);
        const step = hours ? hours * minInHour : (scaledMinutes % minInHour);
        extent[0] = Math.ceil(extent[0] / step) * step;
        // eslint-disable-next-line no-magic-numbers
        extent[1] = Math.floor(extent[1] / step) * step + 0.5 * step;
        return d3.range(extent[0], extent[1], step);
      };
      scale.copy = () => periodLinearScale(domain, range);
      return rescale();
    }