防止缩小传单 R-Map？

Question

我用传单R包制作了一张传单地图。

结果如下：

我对它很满意，但是当我将它嵌入网站并用我的笔记本电脑向下滚动文章时，我经常不小心将地图缩小，然后看起来像这样：

用户还必须放大并查看地图的中间部分，这让我很恼火。

有没有办法冻结地图的一部分，就像你可以像往常一样放大但不能缩小得比图像上的更多？我尝试在我的代码中设置视图，但您仍然可以缩小，所以我删除了那部分。

    mymap <- leaflet() %>% 

addProviderTiles("Esri.WorldGrayCanvas") %>%
addPolygons(data = dortmund, 
            fillColor = ~palette(student1$Anteil),  ## we want the polygon filled with 
            ## one of the palette-colors
            ## according to the value in student1$Anteil
            fillOpacity = 0.6,         ## how transparent do you want the polygon to be?
            color = "darkgrey",       ## color of borders between districts
            weight = 1.5,            ## width of borders
            popup = popup1,         ## which popup?
            group="<span style='color: #7f0000; font-size: 11pt'><strong>2000</strong></span>")%>%  
            ## which group?
            ## the group's name has to be the same as later in "baseGroups", where we define 
            ## the groups for the Layerscontrol. Because for this layer I wanted a specific 
            ## color and size, the group name includes some font arguments.  

## for the second layer we mix things up a little bit, so you'll see the difference in the map!
addPolygons(data = dortmund, 
            fillColor = ~palette(student2$Anteil), 
            fillOpacity = 0.2, 
            color = "white", 
            weight = 2.0, 
            popup = popup2, 
            group="2014")%>%
addLayersControl(
    baseGroups = c("<span style='color: #7f0000; font-size: 11pt'><strong>2000</strong></span>", ## group 1
                   "2014" ## group 2
    ),
    options = layersControlOptions(collapsed = FALSE))%>% ## we want our control to be seen right away
addLegend(position = 'topleft', ## choose bottomleft, bottomright, topleft or topright
           colors = c('#fee0d2',
                      '#fcbba1',
                      '#fc9272',
                      '#fb6a4a',
                      '#ef3b2c',
                      '#cb181d',
                      '#a50f15',
                      '#67000d'), 
           labels = c('0%',"","","","","","",'26%'),  ## legend labels (only min and max)
           opacity = 0.6,      ##transparency 
           title = "relative<br>amount")   ## title of the legend

请原谅我糟糕的英语水平。如果回答我的问题很重要，完整代码在这里：http://journocode.com/2016/01/28/your-first-choropleth-map/。

非常感谢

Answer 1

将您的 addProviderTiles 替换为以下内容（设置您想要的最大和最小缩放级别：

addProviderTiles("Esri.WorldGrayCanvas",
        options = providerTileOptions(minZoom=10, maxZoom=18))

Answer 2

我发现非常有用的是一个“主页”按钮，它可以让您回到初始地图边界和缩放。

leaflet() |>
  addTiles() |> 
    addEasyButton(easyButton(icon = "fas fa-home",
                             title = "Fly back home",
                             position = "topleft",
                             onClick = JS(paste0(
                               "function(btn, map) {
                                      map.fitBounds([
                                        [", -11.25, ",", 40, "], ",
                                        "[", 47.9, ",", -15.37, "]
                                        ])
                                      }"
                             )
                             ))) |>
    fitBounds(lng1 = 40, lat1 = -11.25,
              lng2 = -15.37, lat2 = 47.9)

地理对象的边界框可以用sf::st_bbox()计算。

防止缩小传单 R-Map？

Prevent zooming out in leaflet R-Map?

r

zooming

leaflet