[英]Getting nearest min x and max x data points on zoomcallback?
I am using the zoomcallback on dygraphs, but I have an issue in that the min and max values pased back in the callback are effectively interpolated values. 我在dygraphs上使用zoomcallback,但我有一个问题,即在回调中回调的最小值和最大值是有效插值。 I need to map these callback values to my original dataset which I have hashed my x.
我需要将这些回调值映射到我已经散列x的原始数据集。
Iterating over my original dataset looking for the closest x value for min and the closest value for y is not viable. 迭代我的原始数据集,寻找min的最接近的x值,y的最接近的值是不可行的。
Anyone know a way of getting to the actual data values that are at the min x and max x viewable portion of the graph? 任何人都知道一种获取图表的最小x和最大x可视部分的实际数据值的方法吗?
The getRowForX
method in dygraphs 2.0 does something similar to what you want, but it will only return an index if you match an x-value exactly. dygraphs 2.0中的
getRowForX
方法与您想要的类似,但只有在完全匹配x值时才会返回索引。 It's implemented using binary search. 它是使用二进制搜索实现的。 To get the closest row number for an inexact match only requires a small tweak:
要获得最接近的行号以进行不精确的匹配,只需要进行一些小调整:
function getCloseRowForX(g, xVal) {
var low = 0,
high = g.numRows() - 1;
while (low <= high) {
var idx = (high + low) >> 1;
var x = g.getValue(idx, 0);
if (x < xVal) {
low = idx + 1;
} else if (x > xVal) {
high = idx - 1;
} else {
return idx;
}
}
return idx;
};
In your zoomCallback
you can do something like this: 在你的
zoomCallback
你可以这样做:
zoomCallback() {
const [leftX, rightX] = this.xAxisRange();
const leftIndex = getCloseRowForX(this, leftX);
const rightIndex = getCloseRowForX(this, rightX);
const leftValue = this.getValue(leftIndex, seriesNum);
const rightValue = this.getValue(rightIndex, seriesNum);
}
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.