javascript - 让 Dygraph.WEEKLY 标签使用星期一作为 R 中的刻度

Question

我正在使用 dygraphs 绘制每周数据图表包裹。 dygraphs 自动选择每周默认轴。但是，我希望有一种方法可以让默认轴(星期日)与我的数据(星期一)对齐。

# Required packages
library("magrittr")
library("dygraphs")
library("xts")

# Data
daily <- structure(c(4000, 5000, 3000, 7000, 2000, 5000, 7000, 
                   2000, 3000, 6000, 5000, 9000, 2000, 2000, 2000, 
                   7000, 9000, 2000, 1000, 13000), .Dim = c(10L, 2L), .Dimnames = list(
                     NULL, c("col1", "col2")), index = structure(c(1476032400, 
                                                                   1476637200, 1477242000, 1477846800, 1478451600, 1479056400, 1479661200, 
                                                                   1480266000, 1480870800, 1481475600), tzone = "Asia/Saigon", tclass = c("POSIXct", 
                                                                                                                                          "POSIXt")), class = c("xts", "zoo"), .indexCLASS = c("POSIXct", 
                                                                                                                                                                                               "POSIXt"), tclass = c("POSIXct", "POSIXt"), .indexTZ = "Asia/Saigon", tzone = "Asia/Saigon")

# Graph
dygraph(daily, main = "Stackoverflow") %>%
  dyRangeSelector() %>%
  dyOptions(useDataTimezone = TRUE) 

Answer 1

您可以尝试使用自定义 ticker 函数，该函数从数据的第一天开始，每 7 天打一次勾。

这是一个受 dygraph-tickers.js Dygraph.getDateAxis 函数启发的示例:

dygraph(daily, main = "Stackoverflow") %>%
  dyRangeSelector() %>%
  dyAxis("x",ticker='function(start_time, end_time, pixels, opts, dygraph, vals) {
         var formatter = opts("axisLabelFormatter");
         var ticks = [];
         var t;
         //spacing is a week in milliseconds
         var spacing = 1000 * 604800;

         for (t = start_time; t <= end_time; t += spacing) {
          ticks.push({ v:t,
         label: formatter(new Date(t), Dygraph.WEEKLY, opts, dygraph)
         });
         }
         return ticks;
   }') %>%
  dyOptions(useDataTimezone = TRUE)