Function calculateStack

src/processor/dataStack.ts:105–175

(stackInfoList: StackInfo[])

}

function calculateStack(stackInfoList: StackInfo[]) {
    each(stackInfoList, function (targetStackInfo, idxInStack) {
        const resultVal: number[] = [];
        const resultNaN = [NaN, NaN];
        const dims: [string, string] = [targetStackInfo.stackResultDimension, targetStackInfo.stackedOverDimension];
        const targetData = targetStackInfo.data;
        const isStackedByIndex = targetStackInfo.isStackedByIndex;
        const stackStrategy = targetStackInfo.seriesModel.get('stackStrategy') || 'samesign';

        // Should not write on raw data, because stack series model list changes
        // depending on legend selection.
        targetData.modify(dims, function (v0, v1, dataIndex) {
            let sum = targetData.get(targetStackInfo.stackedDimension, dataIndex) as number;

            // Consider `connectNulls` of line area, if value is NaN, stackedOver
            // should also be NaN, to draw a appropriate belt area.
            if (isNaN(sum)) {
                return resultNaN;
            }

            let byValue: number;
            let stackedDataRawIndex;

            if (isStackedByIndex) {
                stackedDataRawIndex = targetData.getRawIndex(dataIndex);
            }
            else {
                byValue = targetData.get(targetStackInfo.stackedByDimension, dataIndex) as number;
            }

            // If stackOver is NaN, chart view will render point on value start.
            let stackedOver = NaN;

            for (let j = idxInStack - 1; j >= 0; j--) {
                const stackInfo = stackInfoList[j];

                // Has been optimized by inverted indices on `stackedByDimension`.
                if (!isStackedByIndex) {
                    stackedDataRawIndex = stackInfo.data.rawIndexOf(stackInfo.stackedByDimension, byValue);
                }

                if (stackedDataRawIndex >= 0) {
                    const val = stackInfo.data.getByRawIndex(
                        stackInfo.stackResultDimension, stackedDataRawIndex
                    ) as number;

                    // Considering positive stack, negative stack and empty data
                    if (
                        stackStrategy === 'all' // single stack group
                        || (stackStrategy === 'positive' && val > 0)
                        || (stackStrategy === 'negative' && val < 0)
                        || (stackStrategy === 'samesign' && sum >= 0 && val > 0) // All positive stack
                        || (stackStrategy === 'samesign' && sum <= 0 && val < 0) // All negative stack
                    ) {
                        // The sum has to be very small to be affected by the
                        // floating arithmetic problem. An incorrect result will probably
                        // cause axis min/max to be filtered incorrectly.
                        sum = addSafe(sum, val);