Vector Fields

See a vector field standing in the room in front of you. Vector Fields turns any three-component vector field into arrows you can walk around. Type something like -y, x, 0 and it appears in augmented reality, drawn in the space in front of you at true scale. Built for anyone learning or teaching multivariable calculus, where the hardest part is often picturing what a field actually looks like. Rotation, divergence and flow stop being abstractions once you can lean in and look along an axis. WRITE ORDINARY MATH Expressions are ordinary notation, not code. Implicit multiplication works, so 2x, 3sin(y) and (x+1)(x-1) all parse. Powers use ^ and are right associative. Odd roots of negative numbers give real answers, so (-8)^(1/3) is -2 rather than an error. Supported throughout: sine, cosine, tangent and their reciprocals, inverse and hyperbolic forms, exp, natural and arbitrary-base logs, square and cube roots, hypot, floor, ceil, round, sign, min, max, clamp, mod, and radian/degree conversion. Constants pi, tau, e and phi are built in. MISTAKES ARE EXPLAINED, NOT PUNISHED An unknown function, a stray operator or the wrong argument count produces a plain-language explanation rather than a failure. Some slips are repaired automatically and reported: a missing closing parenthesis is inserted where it belongs, parentheses wrapped around a whole field are removed, and commas inside a function call are no longer mistaken for component separators. SEE IT THE WAY YOU WANT Arrow length tracks the magnitude of the vector at each point, and a slider scales every arrow at once. A second slider sets thickness. Both update the field as you drag. MOVE THE ORIGIN Print ArUco marker ID 0 from the 6x6 dictionary at 100 mm wide (https://chev.me/arucogen/ generates it) and point the camera at it to move the world origin, and with it the grid and every arrow, onto the marker. Useful for putting the field on a desk in front of a class rather than wherever you happened to be standing. People occlusion is supported on devices that offer it, so someone walking through the field is drawn in front of the arrows instead of behind them. Requires an iPhone or iPad with ARKit support. No account, no ads, no tracking and no internet connection needed. Nothing you type ever leaves your device.