How to use the zrender/src/core/util.map function in zrender

console.warn('Visual map on line style only support x or y dimension.');
        }
        return;
    }

    // If the area to be rendered is bigger than area defined by LinearGradient,
    // the canvas spec prescribes that the color of the first stop and the last
    // stop should be used. But if two stops are added at offset 0, in effect
    // browsers use the color of the second stop to render area outside
    // LinearGradient. So we can only infinitesimally extend area defined in
    // LinearGradient to render `outerColors`.

    var axis = coordSys.getAxis(coordDim);

    // dataToCoor mapping may not be linear, but must be monotonic.
    var colorStops = zrUtil.map(visualMeta.stops, function (stop) {
        return {
            coord: axis.toGlobalCoord(axis.dataToCoord(stop.value)),
            color: stop.color
        };
    });
    var stopLen = colorStops.length;
    var outerColors = visualMeta.outerColors.slice();

    if (stopLen && colorStops[0].coord > colorStops[stopLen - 1].coord) {
        colorStops.reverse();
        outerColors.reverse();
    }

    var tinyExtent = 10; // Arbitrary value: 10px
    var minCoord = colorStops[0].coord - tinyExtent;
    var maxCoord = colorStops[stopLen - 1].coord + tinyExtent;

var tickCategoryInterval; // Optimize for the case that large category data and no label displayed,
  // we should not return all ticks.

  if (!tickModel.get('show') || axis.scale.isBlank()) {
    ticks = [];
  }

  if (zrUtil.isFunction(optionTickInterval)) {
    ticks = makeLabelsByCustomizedCategoryInterval(axis, optionTickInterval, true);
  } // Always use label interval by default despite label show. Consider this
  // scenario, Use multiple grid with the xAxis sync, and only one xAxis shows
  // labels. `splitLine` and `axisTick` should be consistent in this case.
  else if (optionTickInterval === 'auto') {
      var labelsResult = makeCategoryLabelsActually(axis, axis.getLabelModel());
      tickCategoryInterval = labelsResult.labelCategoryInterval;
      ticks = zrUtil.map(labelsResult.labels, function (labelItem) {
        return labelItem.tickValue;
      });
    } else {
      tickCategoryInterval = optionTickInterval;
      ticks = makeLabelsByNumericCategoryInterval(axis, tickCategoryInterval, true);
    } // Cache to avoid calling interval function repeatly.


  return listCacheSet(ticksCache, optionTickInterval, {
    ticks: ticks,
    tickCategoryInterval: tickCategoryInterval
  });
}

function dataToCoordSize(dataSize, dataItem) {
    dataItem = dataItem || [0, 0];
    return zrUtil.map([0, 1], function (dimIdx) {
        var val = dataItem[dimIdx];
        var halfSize = dataSize[dimIdx] / 2;
        var p1 = [];
        var p2 = [];
        p1[dimIdx] = val - halfSize;
        p2[dimIdx] = val + halfSize;
        p1[1 - dimIdx] = p2[1 - dimIdx] = dataItem[1 - dimIdx];
        return Math.abs(this.dataToPoint(p1)[dimIdx] - this.dataToPoint(p2)[dimIdx]);
    }, this);
}

proto.makePanelOpts = function (api, getDefaultBrushType) {
    return zrUtil.map(this._targetInfoList, function (targetInfo) {
        var rect = targetInfo.getPanelRect();
        return {
            panelId: targetInfo.panelId,
            defaultBrushType: getDefaultBrushType && getDefaultBrushType(targetInfo),
            clipPath: brushHelper.makeRectPanelClipPath(rect),
            isTargetByCursor: brushHelper.makeRectIsTargetByCursor(
                rect, api, targetInfo.coordSysModel
            ),
            getLinearBrushOtherExtent: brushHelper.makeLinearBrushOtherExtent(rect)
        };
    });
};

_buildAxes: function (radarModel) {
        var radar = radarModel.coordinateSystem;
        var indicatorAxes = radar.getIndicatorAxes();
        var axisBuilders = zrUtil.map(indicatorAxes, function (indicatorAxis) {
            var axisBuilder = new AxisBuilder(indicatorAxis.model, {
                position: [radar.cx, radar.cy],
                rotation: indicatorAxis.angle,
                labelDirection: -1,
                tickDirection: -1,
                nameDirection: 1
            });
            return axisBuilder;
        });

        zrUtil.each(axisBuilders, function (axisBuilder) {
            zrUtil.each(axisBuilderAttrs, axisBuilder.add, axisBuilder);
            this.group.add(axisBuilder.getGroup());
        }, this);
    },

getCategories: function () {
    return this.get('type') === 'category' && zrUtil.map(this.get('data'), getName);
  },

function setVisualToOption(thisOption, visualArr) {
  thisOption.visual = visualArr;

  if (thisOption.type === 'color') {
    thisOption.parsedVisual = zrUtil.map(visualArr, function (item) {
      return zrColor.parse(item);
    });
  }

  return visualArr;
}
/**

function compatEc2(seriesOpt) {
  var data = seriesOpt.data;

  if (data && data[0] && data[0][0] && data[0][0].coord) {
    seriesOpt.data = map(data, function (itemOpt) {
      var coords = [itemOpt[0].coord, itemOpt[1].coord];
      var target = {
        coords: coords
      };

      if (itemOpt[0].name) {
        target.fromName = itemOpt[0].name;
      }

      if (itemOpt[1].name) {
        target.toName = itemOpt[1].name;
      }

      return mergeAll([target, itemOpt[0], itemOpt[1]]);
    });
  }

function getCoverInfoList(axisModel) {
  var axis = axisModel.axis;
  return zrUtil.map(axisModel.activeIntervals, function (interval) {
    return {
      brushType: 'lineX',
      panelId: 'pl',
      range: [axis.dataToCoord(interval[0], true), axis.dataToCoord(interval[1], true)]
    };
  });
}

function assembleOtherSeries(series) {
  return zrUtil.map(series, function (series) {
    var data = series.getRawData();
    var lines = [series.name];
    var vals = [];
    data.each(data.dimensions, function () {
      var argLen = arguments.length;
      var dataIndex = arguments[argLen - 1];
      var name = data.getName(dataIndex);

      for (var i = 0; i < argLen - 1; i++) {
        vals[i] = arguments[i];
      }

      lines.push((name ? name + ITEM_SPLITER : '') + vals.join(ITEM_SPLITER));
    });
    return lines.join('\n');
  }).join('\n\n' + BLOCK_SPLITER + '\n\n');