function redrawChart() {
    const enabledRegionsIds = regionsIds.filter(regionId => regions[regionId].enabled);

    const paths = svg
      .selectAll('.line')
      .data(enabledRegionsIds);

    paths.exit().remove();

    paths
      .enter()
      .append('path')
      .merge(paths)
      .attr('class', 'line')
      .attr('id', regionId => `region-${ regionId }`)
      .attr('d', regionId => lineGenerator(regions[regionId].data)
      )
      .style('stroke', regionId => colorScale(regionId));

    legends.each(function(regionId) {
      const opacityValue = enabledRegionsIds.indexOf(regionId) >= 0 ? ENABLED_OPACITY : DISABLED_OPACITY;

      d3.select(this).attr('opacity', opacityValue);
    });
  }