ActionScript 2 help please!

Math.sqrt(number)

I don't know where you want the divisor to be

Math.sqrt(drag*area)
or
(Math.sqrt(drag*area)*speed)

e.g.
permissible = hookload*1.2/(Math.sqrt(drag*area)*speed)

Maybe I'm missing something obvious but I'm afraid I don't understand your requirements.

If you want the square root of drag*area

then its

Math.sqrt(drag*area)

division takes precedence over multiplication...
so you put brackets around anything that should be evaluated first that conflicts with that...

This might help:

var test = 3*2/Math.sqrt(4*4)*3

//is evaluated like this:

//Math.sqrt is first...

// 3*2/4*3

// 3*0.5*3

// 1.5*3

//4.5

trace(test)

>> division takes precedence over multiplication...

Actually, they have the same order.
Example: trace( 4 * 4 / 4);

You get 4, not 1...



--
Dave -
Head Developer
http://www.blurredistinction.com
Adobe Community Expert
http://www.adobe.com/communities/experts/

>>You get 4, not 1...

You get 4, not 16... is what I meant to say.

--
Dave -
Head Developer
http://www.blurredistinction.com
Adobe Community Expert
http://www.adobe.com/communities/experts/

I stand corrected - I understand what you mean. Its been a while since I studied math.

Although your example gives 4 either way (4*(4/4) is 4*1... is 4). & (4*4) /4..... 16/4 is also 4.

What I meant to say was that

4*4/4*4 is different to 4*4/(4*4) and won't be interpreted that way.

erm, not to be splitting hairs, but doesn't 4*4/4 retun 4 in any order you calculate it?

and
4*4/(4*4) = 1
4*(4/(4*4)) = 1
(4*4)/(4*4) = 1

em.. i think it just.. em... doesn't prove much...

edit: blimey... 4*4/4*4 is 16.... that means... uh... math...

permissible = Math.sqrt(hookload*1.2/(drag*area))*speed

quote:

---

Originally posted by: groveman

permissible = hookload*1.2/(drag*area)*speed)

---

The reason this gives a syntax error is because you don't have the correct number of parenthesis.

permissible = (hookload*1.2)/((drag*area)*speed);

Notice the two opening parenthesis before drag. I also added parenthesis around the hookload equation for good measure.

Hope this helps. When doing these type of equations you have to be very careful about grouping and your syntax. When you have three opening parenthesis, for example, you must have 3 closing.

John

erm.. ok.. i get it... i think..

4*4/4*4 is different from 4*4/(4*4) .. . but I'm not sure it that shows precedence of division.. just lack of precedence of multiplication... i think...

@cicnats:

trace(4*4/(4*4)) //1
trace(4*4/4*4) //16

@cicnats... yeah like I said.... I didn't express it properly. Sorry for adding to the confusion

I think we can agree that the lesson learned is to use parenthesis whenever in doubt :)

but to push the case one last time.. I think you may be right.. since it seems flash does implement precedence of multiplication over addition.. it probably precedes division over multiplication, because I think I remember from math that it should be that way..

oh.. and lesson 2 to read code more carefully so we don't go off topic (i mean, since the problem was a syntax error due to a typo) :)

@groveman: in case you missed it, I posted what I think you were looking for a few posts up....

permissible = Math.sqrt(hookload*1.2/(drag*area))*speed

@cicnats: agreed. I tend to over use parentheses to help me interpret the code when I look at it next time (if that makes sense...sometimes it can be difficult when there are lots).
The idea of multiplication over addition as a math rule is something I had 'embedded' as some vague recollection so I wasn't 100% sure. I did see the typo too but focused on the other stuff because it seemed like the real issue was trying to get the right calculation in the first place.