Does anyone have a script for adding an anchor point to the top-most point of a path?

An improved action set is availabe here:

Point Maker 3

It contains two additional actions that create points at all outer peaks of single or multiple selected curved paths.

point_maker_all_single_selection is supposed to work with single selected paths only.

point_maker_all_multiple_selection can handle multiple selected (ungrouped and non-overlapping) paths. It's a bit long-winded and it could be simplified. But this simplification would require some interaction by the user, so I didn't implement that option, accepting that it is just another bumpy ride.

I won't be able to do anything over the weekend, so I thought I would post my progress.  Step one, finding the extrema of the segments, is done.  The math was not as hard as I thought.  (Step two would be redrawing the path with one or more of these points.) 

// select path
var doc = app.activeDocument;
var Ps = doc.selection[0].pathPoints;
// iterate segments
for (var i = 0; i < Ps.length - 1; i++) {
    var Px = [Ps[i].anchor[0], Ps[i].rightDirection[0], Ps[i + 1].leftDirection[0], Ps[i + 1].anchor[0]];
    var Py = [Ps[i].anchor[1], Ps[i].rightDirection[1], Ps[i + 1].leftDirection[1], Ps[i + 1].anchor[1]];
    getNDrawPoint();
}
function getNDrawPoint() {
    // get cubic Bezier curve extrema
    // for further info:  https://pomax.github.io/bezierinfo/#extremities
    var a = 3 * Py[3] - 9 * Py[2] + 9 * Py[1] - 3 * Py[0];
    var b = 6 * Py[0] - 12 * Py[1] + 6 * Py[2];
    var c = 3 * Py[1] - 3 * Py[0];
    var t1 = (- b + Math.sqrt(b * b - 4 * a * c)) / (2 * a);
    if (t1 > 0 && t1 < 1) var p1 = getPoint(Px, Py, t1);
    var t2 = (- b - Math.sqrt(b * b - 4 * a * c)) / (2 * a);
    if (t2 > 0 && t2 < 1) var p2 = getPoint(Px, Py, t2);
    // draw point(s)
    if(p1) drawPoint(p1[0], p1[1])
    if(p2) drawPoint(p2[0], p2[1])
}
function getPoint(Px, Py, t) {
    var x = Px[0] * (1 - t) * (1 - t) * (1 - t) + 3 * Px[1] * t * (1 - t) * (1 - t) + 3 * Px[2] * t * t * (1 - t) + Px[3] * t * t * t;
    var y = Py[0] * (1 - t) * (1 - t) * (1 - t) + 3 * Py[1] * t * (1 - t) * (1 - t) + 3 * Py[2] * t * t * (1 - t) + Py[3] * t * t * t;
    return [x, y];
}
function drawPoint(x, y) {
    var path1 = doc.pathItems.add();
    path1.setEntirePath([[x - 0.5, y + 0.5], [x + 0.5, y - 0.5]]);
    var path2 = doc.pathItems.add();
    path2.setEntirePath([[x + 0.5, y + 0.5], [x - 0.5, y - 0.5]]);
    path2.strokeWidth = path1.strokeWidth = 5;
    path2.strokeColor = path1.strokeColor = doc.swatches["CMYK red"].color;
    var group1 = doc.groupItems.add();
    path1.moveToEnd(group1);
    path2.moveToEnd(group1);
}

Eduard,

if it is – for some reason – required to run the actions via scripts, you can download them here:

Point Maker Scripts

It contains four simple scripts that will run the actions in the Point Maker 2 action set.

Instruction:

- Download and unzip the file

- Important: In the Actions palette, first make sure that you've imported the action set point_maker_2.aia

- Select a curved path and run one of the scripts, for example point_maker_top.jsx

That should work pretty well.

I think this is an interesting problem, scripting wise. There are two steps. First, finding the maximum (or minimum) of the Bezier curve function of a segment. One may need to brush up their calculus. Two, since it's not possible to add a point to the middle of the segment, the whole segment will have to be redrawn with the added point. I'll think about it when I have the time.

You can download an action set file here:

Point Maker 2

It contains four actions that can make points at different positions on curved paths (topmost, bottommost, leftmost and rightmost).

Instruction:

- Download and unzip the file
- In the Actions palette import the action set file (point_maker_1.aia)
- Select an arc or any other curved path
- Run one of the actions
- Do some experiments

Note that the actions may fail in some cases, but they certainly work in many cases.

There is a plugin that can add points at these extreme positions (or move existing points there): VectorScribe

So if you need it often, that might be an option.

can you show a screen shot of a path showing what you need?