Hi!
First, I thought of writing a module() that performs some calculations and returns a value. (but failed.)Is it impossible to return any values from a module()?
This is a working module()
My wish would have been to return the variable "points" from the module(), instead of create the polygon()

radius = 10;angles = [0, 90];

module sector(radius, angles, fn = 24) {    r = radius / cos(180 / fn);    step = -360 / fn;
    points = concat([[0, 0]],        [for(a = [angles[0] : step : angles[1] - 360])             [r * cos(a), r * sin(a)]        ],        [[r * cos(angles[1]), r * sin(angles[1])]]    );
    difference() {        circle(radius, $fn = fn);        polygon(points);    }}

Then I tried to create a function() that handles some calculations and returns a value
(but failed.)Is it impossible to handle a few calculations in a function()?

can take the same example above - is it possible?

points = function ??? () .....

Is there another option to solve my wish?

Modules create objects ie geometry 2D or 3D objects, that get displayed in preview/render.

The result of Modules can be used in 'Children()' but that is an advanced topic.

Functions return a single result, number, string, vector etc.

From: Jan Öhman [mailto:jan_ohman@yahoo.com]
Sent: Mon, 28 Mar 2022 10:15
To: OpenSCAD General Discussion
Subject: [OpenSCAD] Restrictions on functions and modules or .other alternative

Hi!

First, I thought of writing a module() that performs some calculations and returns a value. (but failed.)

Is it impossible to return any values from a module()?

This is a working module()
My wish would have been to return the variable "points" from the module(), instead of create the polygon()

radius = 10;

angles = [0, 90];

module sector(radius, angles, fn = 24) {

r = radius / cos(180 / fn);

step = -360 / fn;



points = concat([[0, 0]],

    [for(a = [angles[0] : step : angles[1] - 360]) 

        [r * cos(a), r * sin(a)]

    ],

    [[r * cos(angles[1]), r * sin(angles[1])]]

);



difference() {

    circle(radius, $fn = fn);

    polygon(points);

}

}

Then I tried to create a function() that handles some calculations and returns a value

(but failed.)

Is it impossible to handle a few calculations in a function()?

can take the same example above - is it possible?

points = function ??? () .....

Is there another option to solve my wish?

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thank you! this is exactly what I was looking for - almost ...
This program (at the bottom) Is a bit modified towards the presented solution and creates two number series with coordinates.
But, how to combine several series? (this doesn't work)points1 =[[10, 10], [10, -0.0197717], [8.74419, 0.0592372], [7.50818, 0.295018], [6.31148, 0.683852], [5.17294, 1.21961], [4.11053, 1.89383], [3.14099, 2.6959], [2.27963, 3.61316], [1.54003, 4.63114], [0.933839, 5.73379], [0.470631, 6.90372], [0.157706, 8.12248], [0, 9.37085]]
points2 =[[10, 50], [-0.0197717, 50], [0.0592372, 51.2558], [0.295018, 52.4918], [0.683852, 53.6885], [1.21961, 54.8271], [1.89383, 55.8895], [2.6959, 56.859], [3.61316, 57.7204], [4.63114, 58.46], [5.73379, 59.0662], [6.90372, 59.5294], [8.12248, 59.8423], [9.37085, 60]]

polygon(points1, points2);

This instructions works as desire .:points =[[10, -0.0197717], [8.74419, 0.0592372], [7.50818, 0.295018], [6.31148, 0.683852], [5.17294, 1.21961], [4.11053, 1.89383], [3.14099, 2.6959], [2.27963, 3.61316], [1.54003, 4.63114], [0.933839, 5.73379], [0.470631, 6.90372], [0.157706, 8.12248], [0, 9.37085],        [-0.0197717, 50], [0.0592372, 51.2558], [0.295018, 52.4918], [0.683852, 53.6885], [1.21961, 54.8271], [1.89383, 55.8895], [2.6959, 56.859], [3.61316, 57.7204], [4.63114, 58.46], [5.73379, 59.0662], [6.90372, 59.5294], [8.12248, 59.8423], [9.37085, 60]];
polygon(points);

My program below
fn = 50;radius1 = 10;angles1 = [0, 90];rotate1 = 1;      // 1 medurs, -1 motursstartAngel1 = "bottom";x1 = 10;y1 = 10;
// points1 = circSect();points1 = circSect(x1, y1, radius1, angles1, startAngel1, rotate1, fn);polygon(points1);

points2 = circSect(10, 50, 10, [0, 90], "left", 1, fn);polygon(points2);

function circSect(x=0, y=0, radius=10, angles=[0,270], startRef="bottom", rotate=1, fn=24)  =    let(        startAngel  = (startRef == "left")   ?   0                    : (startRef == "bottom") ?  90                    : (startRef == "right")  ? 180                    : (startRef == "top")    ? 270                    : undef,                r = radius / cos(180 / fn),        step = 360 / fn,        points = [[x, y],            for(a = [angles[0]-startAngel : step : angles[1]-startAngel])                [-rotate * r * cos(a)+x, r * sin(a)+y]]    ) points;

Den måndag 28 mars 2022 18:39:37 CEST, Jordan Brown <openscad@jordan.maileater.net> skrev:  

On 3/27/2022 5:23 PM, nop head wrote:

function sector(radius, angles, fn = 24)  =
    let(
        r = radius / cos(180 / fn),
        step = -360 / fn,
       points = concat([[0, 0]],
            [for(a = [angles[0] : step : angles[1] - 360])
                [r * cos(a), r * sin(a)]
            ],
            [[r * cos(angles[1]), r * sin(angles[1])]]
       )
    ) points;

radius = 10;
angles = [0, 90];

echo(sector(radius, angles));

Simplifying a little - the concat isn't necessary; you can just directly create the list:

function sector(radius, angles, fn = 24)  =
let(
r = radius / cos(180 / fn),
step = -360 / fn,
points = [
[0, 0],
for(a = [angles[0] : step : angles[1] - 360])
[r * cos(a), r * sin(a)],
[r * cos(angles[1]), r * sin(angles[1])]
]
) points;

radius = 10;
angles = [0, 90];

echo(sector(radius, angles));

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