2b:null 2c:["$","title",null,{"children":"Mapping and Filtering Data | Paul Plew | Observable"}] 31:[{"id":"9b74b38dd799780e04a8bb41ac76507363066eb8e446d554b42db3b903d6cbb00efc36bd37343953beaebf0dc553b8324b66f9f0d134a23728a3267c1d9bb7af","href":"https://static.observableusercontent.com/files/9b74b38dd799780e04a8bb41ac76507363066eb8e446d554b42db3b903d6cbb00efc36bd37343953beaebf0dc553b8324b66f9f0d134a23728a3267c1d9bb7af","name":"ALL_STATE_stories.csv","type":"text/csv","lastModified":1633712151225.603,"size":676973}] 2f:{"id":"61c3e40cc3b58a75","slug":"mapping-and-filtering-data","title":"\n Mapping and Filtering Data\n","thumbnail":"f28ff5d313f04be7deb4b3db09bdb37217adb7fea36994d9c316648257d9ed5e","access_level":"public","create_time":"$D2021-10-08T16:55:33.373Z","update_time":"$D2021-11-05T17:05:18.954Z","view_time":null,"first_public_time":"$D2021-10-13T03:58:16.701Z","fork":{"id":"bd116742b1f91cf4","slug":"simple-d3","title":"Simple D3","owner":{"id":"f35c755083683fe5","login":"observablehq","name":"Observable"}},"stars":1,"starred":false,"owner":{"type":"team","id":"23732d4817a6de59","login":"paulplew","name":"Paul Plew","avatar_url":"https://avatars-next.observableusercontent.com/22cb60315cf70344aa6224b6fe3bee9d4a91bdaf8cbdfe3c0e669e14c944d901","tier":"starter_2024"},"version":557,"publish_version":557,"role":null,"authored":false,"authors":[{"type":"individual","id":"c698f0c55bc0044b","login":"paulplew","name":"Paul Plew","avatar_url":"https://avatars-next.observableusercontent.com/22cb60315cf70344aa6224b6fe3bee9d4a91bdaf8cbdfe3c0e669e14c944d901","tier":null}],"members":[{"type":"individual","id":"c698f0c55bc0044b","login":"paulplew","name":"Paul Plew","avatar_url":"https://avatars-next.observableusercontent.com/22cb60315cf70344aa6224b6fe3bee9d4a91bdaf8cbdfe3c0e669e14c944d901","tier":null,"role":"editor"}],"comments":[],"custom_thumbnail":false,"trashed":false,"subscribed":null,"forks":3,"collection":null,"type":"notebook","body":{"title":"\n Mapping and Filtering Data\n","cells":[{"id":0,"value":"

\n Mapping and Filtering Data\n

\n\nAn easy way to edit and remove entries from a data set.","pinned":false,"hidden":false,"mode":"html","author":"$undefined","summary":"$undefined"},{"id":84,"value":"rawData = FileAttachment(\"ALL_STATE_stories.csv\").csv()","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":93,"value":"aq.from(rawData).view()","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":448,"value":"

","pinned":false,"hidden":false,"mode":"html","author":"$undefined","summary":"$undefined"},{"id":197,"value":"

\n Mapping\n

\nMapping takes one set of data and maps (morphs) each entry into a different entry.\nOld fields can be updated and new ones can be added. In the example I update the Date field, and add a new field — the covidRatio field. ","pinned":false,"hidden":false,"mode":"html","author":"$undefined","summary":"$undefined"},{"id":102,"value":"data = rawData.map(\n (element) => ({\n ...element, // retain old values using spread syntax\n date: new Date(element.date.substring(0,10)), // update date to hold a Date object\n covidRatio: element.covid / element.total, // add a new field covidRatio that is the ratio of covid news to total news\n })\n );","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":107,"value":"aq.from(data).view()","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":259,"value":"Add a new key in the data object that stores the number of non-covid news stories using the ```map(element => function())``` syntax","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined"},{"id":268,"value":"aq.from(\n data.map(\n (element) => ({\n ...element,\n // add your new key value pair here\n \n })\n)).view();","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":379,"value":"

","pinned":false,"hidden":false,"mode":"html","author":"$undefined","summary":"$undefined"},{"id":206,"value":"

\n Filtering\n

\nFiltering removes entries from an array that are false for some value. In the following example the data entries are kept if the condition e.covidRatio > 0.5 evaluates to true.","pinned":false,"hidden":false,"mode":"html","author":"$undefined","summary":"$undefined"},{"id":110,"value":"ratioOverHalf = data.filter((element) => {\n return element.covidRatio > 0.5\n});","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":230,"value":"If you look closely every number in the ```covidRatio``` column is over 0.5","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined"},{"id":163,"value":"aq.from(ratioOverHalf).view()","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":235,"value":"Update this code to get all the values from your favorite state\n
\n\n don't forget to return your value.\n","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined"},{"id":243,"value":"aq.from(\n data.filter((element) => {\n // add your code here when you run the code it will show up\n \n})).view();","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":366,"value":"

","pinned":false,"hidden":false,"mode":"html","author":"$undefined","summary":"$undefined"},{"id":87,"value":"import { aq } from '@uwdata/arquero'","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"}],"files":"$W31","stdlib":"1","titling":"auto"}} 30:"$2f:body"