Question

我有三个看起来像这样的向量：

x = c(NaN, 15, 16, 14, 14, NaN)
y = c(NaN, NaN, NaN, NaN, NaN, 11)
z = c(17, NaN, NaN, NaN, NaN, 12)

我需要将它们合并到一个向量中。我需要这三个平滑地网格化，并且在存在重叠值的地方（如y和z所示），应优先考虑z的值。最终结果应如下所示：

xyz = c(17, 15, 16, 14, 14, 12)

我已经研究过使用rowSums来处理na，但是在同一个索引上有多个值的情况下这不起作用。我试图尽可能避免循环。

非常确定我可以通过遍历向量来完成此操作，但我正在使用相当大的数据集。

Answer 1

这似乎有效。 NB 它依赖于rev作为数据框的最后一列，然后翻转它以便它首先（即df <- data.frame(x = c(NaN, 15, 16, 14, 14, NaN), y = c(NaN, NaN, NaN, NaN, NaN, 11), z = c(17, NaN, NaN, NaN, NaN, 12)) do.call(dplyr::coalesce, rev(df))）。

function demoFromHTML() {
var pdf = new jsPDF('p', 'pt', 'letter');
// source can be HTML-formatted string, or a reference
// to an actual DOM element from which the text will be scraped.
source = $('.JsPDF tbody')[0];

// we support special element handlers. Register them with jQuery-style 
// ID selector for either ID or node name. ("#iAmID", "div", "span" etc.)
// There is no support for any other type of selectors 
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specialElementHandlers = {
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};
margins = {
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    left: 10,
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// all coords and widths are in jsPDF instance's declared units
// 'inches' in this case
pdf.fromHTML(
source, // HTML string or DOM elem ref.
margins.left, // x coord
margins.top, { // y coord
    'width': margins.width, // max width of content on PDF
    'elementHandlers': specialElementHandlers
},

function (dispose) {
    // dispose: object with X, Y of the last line add to the PDF 
    //          this allow the insertion of new lines after html
    pdf.save('Test.pdf');
}, margins);

Answer 2

或者您可以使用基本R函数na.omit

x = c(NaN, 15, 16, 14, 14, NaN)
y = c(NaN, NaN, NaN, NaN, NaN, 11)
z = c(17, NaN, NaN, NaN, NaN, 12)
dt=data.frame(z=z,x=x,y=y)
unlist(lapply(apply(dt,1,na.omit), `[[`, 1))

[1] 17 15 16 14 14 12

Answer 3

您还可以使用zoo包：

df <- rbind(x, y, z)

#it replaces last row with latest non-NA value therefore z always has priority:
xyz <- zoo::na.locf(df)['z',]

#[1] 17 15 16 14 14 12

<强> 数据：

x <- c(NaN, 15, 16, 14, 14, NaN)
y <- c(NaN, NaN, NaN, NaN, NaN, 11)
z <- c(17, NaN, NaN, NaN, NaN, 12)

将三个载体与NaN合并

3 个答案: