32:T466,viewof selection = { const svg = d3.select(DOM.svg(width, height)) .property("value", []); svg.append("g") .call(xAxis); svg.append("g") .call(yAxis); const dot = svg.append("g") .attr("fill", "none") .attr("stroke", "steelblue") .attr("stroke-width", 1.5) .selectAll("g") .data(data) .enter().append("circle") .attr("transform", d => `translate(${x(d.x)},${y(d.y)})`) .attr("r", d => d.size*30) .attr("fill",function(d){ if(d.name == "65803 Didymos (1996 GT)"){ return "orange" } else {return "black"} }) ; svg.append("g") .call(d3.brush() .extent([[margin.left, margin.top], [width - margin.right, height - margin.bottom]]) .on("start brush end", brushed)); function brushed() { let value = []; if (d3.event.selection) { const [[x0, y0], [x1, y1]] = d3.event.selection; value = data.filter(d => x0 <= x(d.x) && x(d.x) < x1 && y0 <= y(d.y) && y(d.y) < y1); } svg.property("value", value).dispatch("input"); } return svg.node(); }33:T75f,function input(config) { let { form, type = "text", attributes = {}, action, getValue, title, description, format, display, submit, options } = config; if (!form) form = html``; const input = form.input; Object.keys(attributes).forEach(key => { const val = attributes[key]; if (val != null) input.setAttribute(key, val); }); if (submit) form.append( html`` ); form.append( html`` ); if (title) form.prepend( html`

${title}

` ); if (description) form.append( html`

${description}

` ); if (format) format = d3format.format(format); if (action) { action(form); } else { const verb = submit ? "onsubmit" : type == "button" ? "onclick" : type == "checkbox" || type == "radio" ? "onchange" : "oninput"; form[verb] = e => { e && e.preventDefault(); const value = getValue ? getValue(input) : input.value; if (form.output) form.output.value = display ? display(value) : format ? format(value) : value; form.value = value; if (verb !== "oninput") form.dispatchEvent(new CustomEvent("input", { bubbles: true })); }; if (verb !== "oninput") input.oninput = e => e && e.stopPropagation() && e.preventDefault(); if (verb !== "onsubmit") form.onsubmit = e => e && e.preventDefault(); form[verb](); } return form; }34:[] 30:{"title":"Asteroids API (N.E.O.) Exploration","cells":[{"id":0,"value":"Top = md`\n# Asteroids API (N.E.O.) Exploration\n\n\n\n`","pinned":false,"hidden":false,"mode":"ojs"},{"id":900,"value":"Should really update this to make it nicer to look at, but added some code such that all the objects will be black fill except Near Earth Object 65803 Didymos (1996 GT) that the DART mission will attempt to nudge slightly but running straight into its little cousin on September 26th, 2022. Note, the closest distance it will be is actually a few days later, so you have to shift the range 3 days forward to get it in API results.","pinned":false,"hidden":false,"mode":"md"},{"id":407,"value":"$32","pinned":false,"hidden":false,"mode":"ojs"},{"id":772,"value":"md `size of circles in the plot is based max estinated kilometers of the near earth object`","pinned":false,"hidden":false,"mode":"ojs"},{"id":645,"value":"viewof dateChanger = slider({\n min: -365, \n max: 365, \n step: 1, \n description: \"Asteroids & comets are fetched within a 7 day window. Slider changes what day is first of range relative to current day. \"\n})","pinned":false,"hidden":false,"mode":"ojs"},{"id":813,"value":"md `When you move slider, the API call & update takes 1-2 seconds! So move it and then wait...`","pinned":false,"hidden":false,"mode":"ojs"},{"id":786,"value":"dates[0]","pinned":false,"hidden":false,"mode":"ojs"},{"id":757,"value":"md `### Near Earth Objects are fetched based on date of their closest approach of Earth`","pinned":false,"hidden":false,"mode":"ojs"},{"id":597,"value":"md `### If you draw a rectange on the plot above, the data points selected will appear below`","pinned":false,"hidden":false,"mode":"ojs"},{"id":405,"value":"selection","pinned":false,"hidden":false,"mode":"ojs"},{"id":798,"value":"md `_________________`","pinned":false,"hidden":false,"mode":"ojs"},{"id":800,"value":"md `# Code and further explanation`","pinned":false,"hidden":false,"mode":"ojs"},{"id":807,"value":"md `NASA has 18 different public APIs that make it easy to pull different numeric, string, and image data. Examples include space weather, landsat imagery, and asteroids. This notebook is a brief exploration of asteroids. You can also explore the NEO api on their site via Swagger front-end UI. There is also a nice website with some data as already packaged CSV and Excel downloads.`","pinned":false,"hidden":false,"mode":"ojs"},{"id":530,"value":"md `You can check out the various public NASA APIs at API.NASA.GOV.\nAn example call to the NEO API _without_ an autorization token on the end is _https://api.nasa.gov/neo/rest/v1/feed?startDate=2017-01-25&endDate=2017-02-01&api_key=_`\n\n","pinned":false,"hidden":false,"mode":"ojs"},{"id":539,"value":"md `### Getting a NASA API token`","pinned":false,"hidden":false,"mode":"ojs"},{"id":533,"value":"\n\nmd `You might notice the key isn't at the end. In this notebook, we're attaching it programatically. You can add yours in the variable below.`","pinned":false,"hidden":false,"mode":"ojs"},{"id":330,"value":"md ` If you fork this notebook or use it a lot, please get your own API key here. If this notebook doesn't run, first thing to try would be to put in your own API key at bottom.`","pinned":false,"hidden":false,"mode":"ojs"},{"id":334,"value":"md `Note the NASA API service limits Api requests to 1000 per 24 hour period based on unique key per unique IP address. If you don't get any response to your API call, you might also check to make sure your ad blocker isn't interpreting your API call as cross origin and stopping it. EFF's privacy badger has been known to do this. If you white list the API URL, things will work again.`","pinned":false,"hidden":false,"mode":"ojs"},{"id":282,"value":"md `### Switch in your API token here`","pinned":false,"hidden":false,"mode":"ojs"},{"id":349,"value":"switch_with_your_key = \"zLQyfmaclId2Zub8LTHrXFOjSknWfsUfzzHp0Wgx\"","pinned":true,"hidden":false,"mode":"ojs"},{"id":206,"value":"md `##### Other example API calls:

Find some astroids based on date rate using Near Earth Objects Web Service or NEO https://api.nasa.gov/neo/rest/v1/feed?start_date=2017-01-01&end_date=2017-01-03&detailed=true&api_key=
Or check in on your favorite astroid, again using NEO https://api.nasa.gov/neo/rest/v1/neo/3542519?api_key=

`","pinned":false,"hidden":false,"mode":"ojs"},{"id":830,"value":"md `### Code for date selection`","pinned":false,"hidden":false,"mode":"ojs"},{"id":706,"value":"d3format = require(\"d3-format\")","pinned":false,"hidden":false,"mode":"ojs"},{"id":621,"value":"$33","pinned":false,"hidden":false,"mode":"ojs"},{"id":631,"value":"function addDays(date, days) {\n var result = new Date(date);\n result.setDate(result.getDate() + days);\n return result;\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":648,"value":"md`---\nSliders for changing starting date are from\n\\`import {slider} from \"@jashkenas/inputs\"\\``","pinned":false,"hidden":false,"mode":"ojs"},{"id":652,"value":"function slider(config = {}) {\n let {value, min = 0, max = 1, step = \"any\", precision = 2, title, description, getValue, format, display, submit} = config;\n if (typeof config == \"number\") value = config;\n if (value == null) value = (max + min) / 2;\n precision = Math.pow(10, precision);\n if (!getValue) getValue = input => Math.round(input.valueAsNumber * precision) / precision;\n return input({\n type: \"range\", title, description, submit, format, display,\n attributes: {min, max, step, value},\n getValue\n });\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":633,"value":"date = new Date()","pinned":true,"hidden":false,"mode":"ojs"},{"id":683,"value":"md `The API limits the range called to 7 days but it does give you the exact call for the next and previous 7 day period in the response for each call, in case you wanted to chain together several calls.`","pinned":false,"hidden":false,"mode":"ojs"},{"id":783,"value":"dates[0]","pinned":false,"hidden":false,"mode":"ojs"},{"id":643,"value":"newDate = addDays(date,dateChanger)","pinned":true,"hidden":false,"mode":"ojs"},{"id":660,"value":"startDateObj = newDate","pinned":false,"hidden":false,"mode":"ojs"},{"id":663,"value":"endDateObj = addDays(startDateObj,7)","pinned":false,"hidden":false,"mode":"ojs"},{"id":662,"value":"function getDatesAsString(date){\n var month = date.getUTCMonth() + 1; //months from 1-12\n var day = date.getUTCDate();\n var year = date.getUTCFullYear();\n let newdate = year + \"-\" + month + \"-\" + day;\n return newdate\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":661,"value":"startDate = getDatesAsString(startDateObj)","pinned":false,"hidden":false,"mode":"ojs"},{"id":670,"value":"endDate = getDatesAsString(endDateObj)","pinned":false,"hidden":false,"mode":"ojs"},{"id":669,"value":"md `### We then use those dates to make the API call`","pinned":false,"hidden":false,"mode":"ojs"},{"id":614,"value":"url = 'https://api.nasa.gov/neo/rest/v1/feed?start_date='+startDate+'&end_date='+endDate+'&detailed=true&api_key='","pinned":true,"hidden":false,"mode":"ojs"},{"id":342,"value":"md `_ The resulting url sent out when combined with the key is _`","pinned":false,"hidden":false,"mode":"ojs"},{"id":304,"value":"url+switch_with_your_key","pinned":false,"hidden":false,"mode":"ojs"},{"id":347,"value":"md `#### The API call response is below this line. You can click on the arrow to expand the object`","pinned":false,"hidden":false,"mode":"ojs"},{"id":17,"value":"response = {\n const resp = await fetch(url+switch_with_your_key);\n const headers = [...resp.headers.entries()].reduce((_, v) => (_[v[0]] = v[1], _), {});\n let data, error, image;\n if (false) {}\n else if (headers['content-type'].match(/json/)) {\n const text = await resp.text();\n try { data = JSON.parse(text); }\n catch (e) { error = e; }\n }\n else if (headers['content-type'].match(/image/)) {\n const buffer = await resp.arrayBuffer();\n const bytes = [].slice.call(new Uint8Array(buffer));\n const binary = bytes.reduce((a,v)=>(a+=String.fromCharCode(v),a),'');\n image = 'data:image/jpeg;base64,' + window.btoa(binary);\n }\n return { headers, data, image, error };\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":553,"value":"md `#### Note, if you use the first example, the plot below will populate. If you use another API call, the plot will likely not populate correctly.`","pinned":false,"hidden":false,"mode":"ojs"},{"id":591,"value":"md `---------------------------------`","pinned":false,"hidden":false,"mode":"ojs"},{"id":555,"value":"md `### Next section processes API response data into form for plot`","pinned":false,"hidden":false,"mode":"ojs"},{"id":561,"value":"md `Initially, the data from the API response is nested by date, which means each day has one or more objects.`","pinned":false,"hidden":false,"mode":"ojs"},{"id":361,"value":"unflattened_asteroids = response.data.near_earth_objects","pinned":true,"hidden":false,"mode":"ojs"},{"id":564,"value":"unflattened_asteroids","pinned":false,"hidden":false,"mode":"ojs"},{"id":574,"value":"md `For plotting, we want things flattened into an array with one item is one asteroid, so we'll do that with this function`","pinned":false,"hidden":false,"mode":"ojs"},{"id":360,"value":"function takeMultipleDaysAndMerge(asteroid_by_days){\n let asteroids_array = []\n let keys = Object.keys(asteroid_by_days);\n for (let i = 0; i < keys.length; i++){\n asteroids_array.push(asteroid_by_days[keys[i]])\n }\n var merged = [].concat.apply([], asteroids_array);\n return merged\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":687,"value":"html `

Total number of near earth objects over that 7 day period is

`","pinned":false,"hidden":false,"mode":"ojs"},{"id":696,"value":"all_asteroids.length","pinned":false,"hidden":false,"mode":"ojs"},{"id":699,"value":"md `The array of asteroid objects now looks like this`","pinned":false,"hidden":false,"mode":"ojs"},{"id":359,"value":"all_asteroids = takeMultipleDaysAndMerge(unflattened_asteroids)","pinned":true,"hidden":false,"mode":"ojs"},{"id":356,"value":"md `Next function will make a new array that only includes the part used on the plot`","pinned":false,"hidden":false,"mode":"ojs"},{"id":429,"value":"function refactorObj_1(objectRocks){\n let new_astroids_array = []\n \n for (let each = 0; each < objectRocks.length; each++){\n let newRow = {}\n newRow.name = objectRocks[each].name\n newRow.size = objectRocks[each]['estimated_diameter']['kilometers']['estimated_diameter_max']\n newRow.x = objectRocks[each]['close_approach_data'][0]['relative_velocity']['kilometers_per_second']\n newRow.y = objectRocks[each]['close_approach_data'][0]['miss_distance']['lunar']\n new_astroids_array.push(newRow)\n }\n return new_astroids_array\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":581,"value":"md `Now we have the data in the array as we want but we have to add some things for label still.`","pinned":false,"hidden":false,"mode":"ojs"},{"id":428,"value":"data_withoutLabels = refactorObj_1(all_asteroids)","pinned":false,"hidden":false,"mode":"ojs"},{"id":583,"value":"md `This function adds x and y labels`","pinned":false,"hidden":false,"mode":"ojs"},{"id":468,"value":"function addLabels(data_withoutLabels,x_and_y){\n let data = data_withoutLabels\n data.x = x_and_y[0]\n data.y = x_and_y[1]\n return data\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":585,"value":"md `Now we have both the data and labels as we want, so there variable is called data, which we will use in the plot`","pinned":false,"hidden":false,"mode":"ojs"},{"id":470,"value":"data = addLabels(data_withoutLabels,[\"kilometers per second\",\"distance from Earth at closet path in multiples of Earth to Moon distance\"])","pinned":true,"hidden":false,"mode":"ojs"},{"id":774,"value":"dates = [{\"startDate\":startDate,\"endDate\":endDate}]","pinned":false,"hidden":false,"mode":"ojs"},{"id":505,"value":"md `## Code to draw the plot`","pinned":false,"hidden":false,"mode":"ojs"},{"id":354,"value":"height = 600","pinned":false,"hidden":false,"mode":"ojs"},{"id":353,"value":"margin = ({top: 20, right: 30, bottom: 30, left: 40})","pinned":false,"hidden":false,"mode":"ojs"},{"id":392,"value":"x = d3.scaleLinear()\n .domain([0,70]).nice()\n .range([margin.left, width - margin.right])\n// x = d3.scaleLinear()\n// .domain(d3.extent(data, d => d.x)).nice()\n// .range([margin.left, width - margin.right])","pinned":false,"hidden":false,"mode":"ojs"},{"id":398,"value":"y = d3.scaleLinear()\n .domain(d3.extent(data, d => d.y)).nice()\n .domain([0,250])\n .range([height - margin.bottom, margin.top])\n// y = d3.scaleLinear()\n// .domain(d3.extent(data, d => d.y))\n// .range([height - margin.bottom, margin.top])","pinned":true,"hidden":false,"mode":"ojs"},{"id":397,"value":"xAxis = g => g\n .attr(\"transform\", `translate(0,${height - margin.bottom})`)\n .call(d3.axisBottom(x))\n .call(g => g.select(\".domain\").remove())\n .call(g => g.append(\"text\")\n // .attr(\"x\", width - margin.right)\n .attr(\"x\", width/2)\n .attr(\"y\", -10)\n .attr(\"fill\", \"#000\")\n .attr(\"font-size\",\"1rem\")\n .attr(\"font-weight\", \"bold\")\n .attr(\"text-anchor\", \"end\")\n .text(data.x))","pinned":false,"hidden":false,"mode":"ojs"},{"id":396,"value":"yAxis = g => g\n .attr(\"transform\", `translate(${margin.left},0)`)\n .call(d3.axisLeft(y))\n .call(g => g.select(\".domain\").remove())\n .call(g => g.select(\".tick:last-of-type text\").clone()\n .attr(\"x\", 4)\n .attr(\"orient\",\"left\")\n .attr(\"text-anchor\", \"start\")\n .attr(\"font-weight\", \"bold\")\n .attr(\"font-size\",\"1rem\")\n .text(data.y))","pinned":false,"hidden":false,"mode":"ojs"},{"id":395,"value":"d3 = require(\"d3@5\")","pinned":true,"hidden":false,"mode":"ojs"},{"id":419,"value":"md `plot is based on this: https://beta.observablehq.com/@mbostock/d3-scatterplot-matrix`","pinned":false,"hidden":false,"mode":"ojs"},{"id":862,"value":"md `--------------------`","pinned":false,"hidden":false,"mode":"ojs"},{"id":729,"value":"md `# Other cool things made with data from this API not on ObservableHQ`","pinned":false,"hidden":false,"mode":"ojs"},{"id":731,"value":"md `This dataset was used as part of the SpaceApps hackathon in 2015 and this https://github.com/Widrogo/StartDust one in particular is good example of a hackathon project using this API.`","pinned":false,"hidden":false,"mode":"ojs"},{"id":733,"value":"md `An R studio notebook exploration of the API here`","pinned":false,"hidden":false,"mode":"ojs"},{"id":735,"value":"md `Asterank is a very well done website with 3D visuals and estimates of asteroid monetary value, if you're into asteroid mining.`","pinned":false,"hidden":false,"mode":"ojs"}],"files":"$W34","stdlib":"1","titling":"auto"}