how to create an isometric peg board?

Does anyone know how I would modify this little bit of code to create a true isometric peg board? My logic to just shift the pegs down every other row is flawed. I apparently have to do something with 30 degree angles, but I can't seem to wrap my head around it :confused:

Code:

---

pegDistance = 50;
pegNum = 1;
for (i = 0; i < 10; i++){
        for (j = 0; j < 10; j++){
                this.attachMovie("peg","peg"+pegNum, pegNum, {_x:i*pegDistance, _y:j*pegDistance});
                if (i%2){
                        this["peg"+pegNum]._y += pegDistance/2;
                }
                pegNum++;               
        }
}

---

for example this, or you could just nest two mcs, rotate one and scale another.

Thanks for the tips! It seems I found a much simpler way of doing it though, which I have posted below.

Code:

---

isoRadians = 30 * Math.PI / 180;
verticalDistance = 40;
horizontalDistance = Math.cos(isoRadians) * verticalDistance;
pegNum = 1;
for (i = 0; i < 10; i++){
        for (j = 0; j < 10; j++){
                this.attachMovie("peg","peg"+pegNum, pegNum, {_x:i*horizontalDistance, _y:j*verticalDistance});
                if (i%2){
                        this["peg"+pegNum]._y += verticalDistance/2;
                }
                pegNum++;
        }
}

---

OR

Code:

---

isoRadians = 30 * Math.PI / 180;
horizontalDistance = 40;
verticalDistance = Math.tan(isoRadians) * horizontalDistance * 2;
pegNum = 1; 
for (i = 0; i < 10; i++){
        for (j = 0; j < 10; j++){
                this.attachMovie("peg","peg"+pegNum, pegNum, {_x:i*horizontalDistance, _y:j*verticalDistance});
                if (i%2){
                        this["peg"+pegNum]._y += verticalDistance/2;
                }
                pegNum++;
        }
}

---

I used this page to understand the logic of an isometric grid and this page to snag the math. The source code of the latter is great because it covers almost every situation where you know only a handful of attributes of a triangle.