Mathematical engineer. Software developer at Act Now Coalition.
l = L(θs, φs, θp, φp)
import { julianDate, solar } from "@mbostock/star-map/2"
todaySunPosition = dt.map(d => sun(d, lat, lon))
function L(θp, φp, θs, φs) {
const { acos, cos, sin, transpose, pow } = math;
const [AY, BY, CY, DY, EY] = _.flatten(G_Y.toArray());
const [Ax, Bx, Cx, Dx, Ex] = _.flatten(G_x.toArray());
const [Ay, By, Cy, Dy, Ey] = _.flatten(G_y.toArray());
const 𝛾p = acos(sin(θs) * sin(θp) * cos(φp - φs) + cos(θs) * cos(θp));
const l = (A, B, C, D, E) =>
(1 + A * pow(Math.E, 1 / cos(θp))) *
(1 + C * pow(Math.E, D * 𝛾p) + E * pow(cos(𝛾p), 2));
const LY = l(AY, BY, CY, DY, EY);
const Lx = l(Ax, Bx, Cx, Dx, Ex);
const Ly = l(Ay, By, Cy, Dy, Ey);
return [LY, Lx, Ly];
}
c = L(Math.PI / 0.9, 0.92, 0.91, 0.9)
rgb_color = lrgb_rgb(xyzd50_lrgb(c))
viewof cl = Inputs.color({ value: rgb_color })
import {
tristimulus_d50,
rgb_lrgb,
lrgb_rgb,
lrgb_xyzd50,
xyzd50_lrgb,
xyzd50_lab,
lab_xyzd50
} from "@mbostock/lab-and-rgb"
function sunPosition(date, lat, lon) {
const positionRadians = suncalc.getPosition(date, lat, lon);
const azimuth = rad2deg(positionRadians.azimuth) + 180;
const altitude = rad2deg(positionRadians.altitude);
return {
azimuth,
altitude,
zenith: 90 - altitude
};
}
rad2deg = (rad) => (180 * rad) / Math.PI
beta = 0.1
globe(attitude().angles([0, 0, 0]))
function globe(attitude, options = {}) {
// Adapted from https://observablehq.com/@fil/attitude
const margin = 10;
const width = 400;
const height = 400;
const context = DOM.context2d(width, height);
const extent = [
[margin, margin],
[height - margin, width - margin]
];
const projection = d3
.geoOrthographic()
.fitExtent(extent, { type: "Sphere" })
.rotate(attitude.angles());
const path = d3.geoPath(projection, context);
const horizon = d3.geoCircle().center([lon, lat]).radius(90);
const sunPos = sun(new Date(), lat, lon);
function drawGlobe() {
context.strokeStyle = "#000";
context.fillStyle = "#ddd";
// World
context.beginPath();
context.fillStyle = "#eee";
path(world);
context.fill();
// Graticule
context.beginPath();
context.strokeStyle = "#000";
context.lineWidth = 0.25;
path(d3.geoGraticule10());
context.stroke();
drawLocation();
drawSunPath();
// Outline
context.beginPath();
context.strokeStyle = "#000";
path({ type: "Sphere" });
context.lineWidth = 1;
context.stroke();
}
function drawLocation() {
context.fillStyle = "red";
context.strokeStyle = "red";
context.lineWidth = 1;
// Location Point
context.beginPath();
path({ type: "Point", coordinates: [lon, lat] });
context.fill();
// Horizon
context.beginPath();
path(horizon());
context.stroke();
}
function drawSunPath() {
context.beginPath();
context.strokeStyle = "orange";
path({
type: "Polygon",
coordinates: [
todaySunPosition.map((d) => [
d.azimuth_deg + 180,
-1 * (90 - lat - d.altitude_deg)
])
]
});
context.stroke();
context.beginPath();
context.fillStyle = "orange";
path({
type: "Point",
coordinates: [
(sunPos.azimuth * 180) / Math.PI + 180,
-1 * (90 - lat - sunPos.altitude_deg)
]
});
context.fill();
}
function render() {
context.save();
context.clearRect(0, 0, width, height);
drawGlobe();
}
d3.select(context.canvas)
.style("cursor", "grab")
.call(
drag(projection, options)
.on("drag.render", render)
.on("end.render", render)
);
return d3.select(context.canvas).call(render).node();
}
startToday = luxon.DateTime.now().startOf('day')
endToday = luxon.DateTime.now().endOf('day')
dt = d3.range(startToday, endToday, 60*1000)
dt.map(d => new Date(d))
function sun(date, lat, lon) {
const _sun = suncalc.getPosition(date, lat, lon)
return {
date: new Date(date),
altitude: _sun.altitude,
azimuth: _sun.azimuth,
altitude_deg: rad2deg(_sun.altitude),
azimuth_deg: rad2deg(_sun.azimuth)
}
}
attitude = require("attitude")
import { drag} from '@fil/attitude'
todaySunPosition.map((d) => [d.azimuth_deg, d.altitude_deg])
sunShape = ({
type: "Point",
coordinates: [
rad2deg(sun(new Date(), lat, lon).azimuth) + 180,
sun(new Date(), lat, lon).altitude_deg
]
})
function formatDecimal(value, places = 2) {
return Intl.NumberFormat(undefined, {
minimumFractionDigits: places,
maximumFractionDigits: places
}).format(value);
}
function printMatrix(name, matrix) {
return tex.block`
${name} =
\begin{pmatrix}
${matrix.map((cells) => cells.join(" & ")).join("\\\\")}
\end{pmatrix}
`;
}
printMatrix("M_Y", M_Y.toArray())
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