45:["$","title",null,{"children":"Transforms / Observable Plot | 1907040202 | Observable"}] 4d:T584,Plot 的内置选项转换有: * [group](/@observablehq/plot-group) - 对有序数据进行分组并导出汇总统计信息，例如 counts * [bin](/@observablehq/plot-bin) - bin 定量数据并导出汇总统计数据，例如 counts * [stack](/@observablehq/plot-stack) - 堆栈系列，例如将 y 转换为 y1 和 y2 * [map](/@observablehq/plot-map) - 每个系列的地图值，例如累计金额 * [window](/@observablehq/plot-window) - 每个窗口系列的地图值，例如滚动平均值 * [select](/@observablehq/plot-select) - 每个系列提取一个值，例如最后一个值 * [interval](/@observablehq/plot-interval) - 将单个值转换为间隔 [start, stop] Next API Reference4e:[{"id":"75d52e6c3130b1cae83cda89305e17b50f33e7420ef205587a135e8562bcfd22e483cf4fa2fb5df6dff66f9c5d19740be1cfaf47406286e2eb6574b49ffc685d","href":"https://static.observableusercontent.com/files/75d52e6c3130b1cae83cda89305e17b50f33e7420ef205587a135e8562bcfd22e483cf4fa2fb5df6dff66f9c5d19740be1cfaf47406286e2eb6574b49ffc685d","name":"alphabet.csv","type":"text/csv","lastModified":1636818801940.567,"size":275},{"id":"a139d402230eaac422551e10fd6785ffa6fc986abe2648574a7361c1d93e15a686aee8ab7bfd6105bc1ee3fd3a33c6a1a6683963607ffe71171c325a6e476737","href":"https://static.observableusercontent.com/files/a139d402230eaac422551e10fd6785ffa6fc986abe2648574a7361c1d93e15a686aee8ab7bfd6105bc1ee3fd3a33c6a1a6683963607ffe71171c325a6e476737","name":"bls-metro-unemployment.csv","type":"text/csv","lastModified":1636818801940.567,"size":406211},{"id":"39837ec5121fcc163131dbc2fe8c1a2e0b3423a5d1e96b5ce371e2ac2e20a290d78b71a4fb08b9fa6a0107776e17fb78af313b8ea70f4cc6648fad68ddf06f7a","href":"https://static.observableusercontent.com/files/39837ec5121fcc163131dbc2fe8c1a2e0b3423a5d1e96b5ce371e2ac2e20a290d78b71a4fb08b9fa6a0107776e17fb78af313b8ea70f4cc6648fad68ddf06f7a","name":"metros.csv","type":"text/csv","lastModified":1636818801940.567,"size":15389}] 49:{"id":"fa62ea839abca0af","slug":"transforms-observable-plot","title":"Transforms / Observable Plot","thumbnail":"0cae20c610afa2634c982342f1c30d369546e21e85ea5b763609a8f1d3ee0d0b","access_level":"public","create_time":"$D2021-11-13T15:53:21.940Z","update_time":"$D2021-11-15T09:32:11.679Z","view_time":null,"first_public_time":"$D2021-11-13T16:25:36.800Z","has_unpublished_edits":null,"fork":{"id":"2e3ea65af40a30c2","slug":"plot-transforms","title":"Transforms / Observable Plot","owner":{"id":"f35c755083683fe5","login":"observablehq","name":"Observable"}},"stars":0,"starred":false,"owner":{"type":"team","id":"ab56f65a3c59a775","login":"1907040202","name":"","avatar_url":null,"tier":"starter_2024","bio":"","followed_by_you":false,"follows_you":false},"version":238,"publish_version":238,"role":null,"authored":false,"authors":[{"type":"individual","id":"422dae94408264fe","login":"1907040202","name":"","avatar_url":null,"tier":null,"bio":"","followed_by_you":false,"follows_you":false}],"members":[{"type":"individual","id":"422dae94408264fe","login":"1907040202","name":"","avatar_url":null,"tier":null,"role":"editor"}],"comments":[],"custom_thumbnail":false,"trashed":false,"lapsed":null,"subscribed":null,"forks":1,"collection":null,"type":"notebook","body":{"titling":"auto","title":"Transforms / Observable Plot","cells":[{"id":117,"value":"md`

Transforms / Observable Plot

Observable Plot › Transforms · API

\n\n# Plot: Transforms\n\nTransforms提供了一种在绘图时导出数据的便捷机制。所有标记都支持以下基本转换：:\n\n* **filter** - 根据指定的访问器或值过滤数据\n* **sort** - 根据指定的比较器、访问器或值对数据进行排序\n* **reverse** - 反转已排序（如果未排序，则为输入）数据顺序\n\n例如，取英文字母频率的玩具条形图，只为通常形成元音的字母画出条形：`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":119,"value":"Plot.barY(alphabet, {filter: d => /[aeiou]/i.test(d.letter), x: \"letter\", y: \"frequency\"}).plot()","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":141,"value":"alphabet = FileAttachment(\"alphabet.csv\").csv({typed: true})","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":121,"value":"md`**filter** 变换类似于用 [*array*.filter](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter) 过滤数据，但是它会保留 [faceting](#faceting) 并且不会影响推断出的[scale domains](#scale-options)；域是从未过滤的通道值中推断出来的。`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":124,"value":"Plot.barY(alphabet.filter(d => /[aeiou]/i.test(d.letter)), {x: \"letter\", y: \"frequency\"}).plot()","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":148,"value":"md`这是另一个使用过滤器变换来控制在密集散点图中显示哪些文本标签的示例。`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":40,"value":"metros = FileAttachment(\"metros.csv\").csv({typed: true})","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":59,"value":"viewof dofilter = Inputs.toggle({label: \"Filter labels\", value: true})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":39,"value":"Plot.plot({\n grid: true,\n inset: 10,\n x: {\n type: \"log\",\n label: \"Population →\",\n tickFormat: \"~s\"\n },\n y: {\n label: \"↑ Inequality\"\n },\n marks: [\n Plot.dot(metros, {\n x: \"POP_2015\",\n y: \"R90_10_2015\",\n r: 2.5}),\n Plot.text(metros, {\n x: \"POP_2015\",\n y: \"R90_10_2015\",\n filter: dofilter ? \"highlight\" : null,\n text: \"nyt_display\",\n dy: -6\n })\n ]\n})","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":114,"value":"md`**排序**和**反向**变换一起允许控制 z 顺序，这在解决过度绘图时很重要。如果 sort 选项是一个函数但不只接受一个参数，则它是一个比较器函数[comparator function](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort#description)；否则，排序选项被解释为通道值定义，因此可以是列名、访问器函数或值数组。`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":69,"value":"bls = FileAttachment(\"bls-metro-unemployment.csv\").csv({typed: true})","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":73,"value":"viewof dosort = Inputs.toggle({label: \"Sort lines\", value: true})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":71,"value":"Plot.plot({\n y: {\n grid: true,\n label: \"↑ Unemployment (%)\"\n },\n color: {\n domain: [false, true],\n range: [\"#ccc\", \"red\"]\n },\n marks: [\n Plot.ruleY([0]),\n Plot.line(bls, {\n x: \"date\",\n y: \"unemployment\",\n z: \"division\",\n sort: dosort && (d => /, MI /.test(d.division)),\n stroke: d => /, MI /.test(d.division)\n })\n ]\n})","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":129,"value":"md`基本转换是可组合的：首先应用过滤器(filter)转换，然后是排序(sort)、反转(reverse)，最后是自定义转换（如果有的话）。`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":13,"value":"md`为了更好地控制，你还可以实现**自定义转换**功能。该函数将 data 和 facets 作为参数并返回相同的参数，其中 data 是关联标记的数据，facets 是该数据的索引数组。如果标记没有分面，则分面将包含代表整个数据的单个分面：[0, 1, ... data.length - 1]。`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":89,"value":"Plot.plot({\n y: {\n grid: true,\n label: \"↑ Unemployment (%)\"\n },\n color: {\n domain: [false, true],\n range: [\"#ccc\", \"red\"]\n },\n marks: [\n Plot.ruleY([0]),\n Plot.line(bls, {\n x: \"date\",\n y: \"unemployment\",\n z: \"division\",\n transform: customTransform\n })\n ]\n})","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":91,"value":"function customTransform(data, facets) {\n return {\n data,\n facets: facets.map(facet => {\n return facet.filter(i => {\n return /, MI /.test(data[i].division);\n });\n })\n };\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":126,"value":"md`Plot 的变换选项，如下所示，不仅仅是填充变换函数，它们还派生出新的标记选项和通道。这些转换采用标记的选项对象（可能还有转换特定的选项作为第一个参数）并返回一个新的、转换的选项。选项转换是可组合的：在将选项对象传递给标记之前，你可以通过多个转换传递选项对象。你还可以在多个标记上重复使用相同的转换选项。`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":0,"value":"$4d","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":235,"value":"","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"}],"files":"$W4e","stdlib":"1"}} 44:null