Equation Painter

Paste an equation, change anything.

Paste a formula copied from the painter, or open one of Hamid Naderi Yeganeh's, and the picture it paints appears beside it. Edit any number, any term, any function: the picture follows as you type.

The formula
The picture redraws half a second after you stop typing. Put the cursor on a number and press Alt + ↑ or ↓ to nudge it by its last digit.
The picture
ready

Pixel formulas

Every pixel gets a colour from H, computed three times with v = 0, 1, 2 for red, green and blue; F clamps it to 0..255. Helpers are defined above H and can use x, y, v and each other.

mode: pixel
size: 1200 x 720
x = (m - 600)/360
y = (360 - n)/360
A = exp(-exp(40*(x^2 + y^2 - 1/4)))
H = (1 + v)/4*A + (1 - A)/10

Families of circles and lines

For every k in a range, or every row of a terms: table, a circle with centre (A, B) and radius R, or a line segment from (X1, Y1) to (X2, Y2). window: auto frames the drawing; linewidth is in the plane's own units.

mode: circles
size: 1200 x 900
window: auto
k = 1 .. 2000
A = cos(2*pi*k/2000)
B = sin(6*pi*k/2000)/2
R = 1/20 + sin(pi*k/2000)^2/10

Painter layers

The painter's own format: a background B, then one row per term, each painted over the last by M and C. The shape of M and C is yours to change; the rows are the constants.

sum(s, 1, 40, expr)   prod(s, 1, 40, expr)
abs sqrt exp ln sin cos tan arctan atan2 arcsin
arccos floor sign min max pick(v, r, g, b)
pi  e  ^  * /  + -   # comment