19 replies to this topic

[BlindWanderer]

so i'm being bad and doing heavy math in autoit and it would be devine if there was atan2

[Valuater]

so i'm being bad and doing heavy math in autoit and it would be devine if there was atan2

Thats part of what is so great about Autoit

You can create UDF's ( User Defined Functions )

Here is your oportunity to be a part of the next release

8)

[markusss]

HELP! what the ef-you-see-k is atan2??

I feel so dumb right now, since everybody (ok its _just_ valuater) knows atan2

Felix

[markusss]

ok i found out that atan2 is:
arctangent(=inverse tangent) with double values

to get the arctangent you do this in autoit:
ATan( expression )

I still don't get the "double" part though... im lost

Felix

Edited by Felix N., 31 October 2005 - 02:12 AM.

[Valuater]

ok i found out that atan2 is:
arctangent(=inverse tangent) with double values

to get the arctangent you do this in autoit:
ATan( expression )

I still don't get the "double" part

hey Felix... you dont need to post about how " dumb" you are or feel

i wish newbies showed half of the effort you do in "finding" the answer to something you dont know...

and that is definetly "not dumb"

8)

[markusss]

Thanks Valuater!

But.... Lol, i still don't get the double thingy, read/googled about it for like 15 mins.... do you know what that is valuater, or could you tell me what what you would do with atan2 (<- i kinda like that word^^)?

Felix N

[Valuater]

no... i actually cannot ( not any more )

i was the only one in my Technical Math college class whom did not have to take the final exam because i past every test with 100% during the semester

... but that was in... um... what year now......like....aaaaa

1974


i did know what it meant.... not the formula

8)

Edited by Valuater, 31 October 2005 - 02:45 AM.

[BlindWanderer]

hmm i guess we don't have any programers...

atan2(y, x) is basicly the same as atan(y/x) except when x equals zero
http://www.redbrick.dcu.ie/help/reference/...ction.atan2.htm

some programing languages don't bother to define atan and only have atan2

[jftuga]

A little off topic....

Compute 4 * atan(1)

:-)

-John

[markusss]

Mhhhhhhm i just love pie, especially fresh apple pie!

Ok BTT:

atan2(y, x) is basicly the same as atan(y/x) except when x equals zero

There we have the answer to the problem, since we have atan(expression) in autoit

Felix N.

[BlindWanderer]

*twitch twitch* i wasn't expecting atan(1/0) to actualy work. I'm not use to it.

well then nm

oh and i wrote a plugin that handles a few obscure math functions.

Attached Files

•  math.zip   54.86KB   320 downloads

Edited by BlindWanderer, 31 October 2005 - 08:37 AM.

[Confuzzled]

no... i actually cannot ( not any more )

i was the only one in my Technical Math college class whom did not have to take the final exam because i past every test with 100% during the semester

... but that was in... um... what year now......like....aaaaa

1974


i did know what it meant.... not the formula

8)

Did your slide rule have the atan2 function engraved on it? Were you allowed to bring your expensive four function calculator to class and actually use it in the tests? Did you sneakily replace it with a scientific one when they first came out and scrunch it back into the original carry case so others wouldn't be suspicious? Did you shuffle the punch cards in the output hopper so the other students couldn't reproduce their software masterpieces again?

My other computer is an abacus...

[BlindWanderer]

Did your slide rule have the atan2 function engraved on it? Were you allowed to bring your expensive four function calculator to class and actually use it in the tests? Did you sneakily replace it with a scientific one when they first came out and scrunch it back into the original carry case so others wouldn't be suspicious? Did you shuffle the punch cards in the output hopper so the other students couldn't reproduce their software masterpieces again?

My other computer is an abacus...

... I was a student of the new age, scientific calculators were manditory in class

[markusss]

Lol, we need graphing ones^^

Your math functions look good, might wanna add some more and you might ask one of the devs to implement them...

Felix N

[Nutster]

Ok, for those that want more details, atan2(y,x) is a little different from atan(y/x) in that atan() just gives you the slope of the line, mapping into the first or fourth co-ordinates, between -pi/2 to +pi/2. atan2() can give an angle between 0 and 2pi (will include 0, but not 2pi).

We are currently in a feature freeze awaiting the next release; we are supposed to be just doing bug fixes at this point, but one of us developers might slip it in. If not, I can slip it into the first beta after the release.

[PsaltyDS]

Ok, for those that want more details, atan2(y,x) is a little different from atan(y/x) in that atan() just gives you the slope of the line, mapping into the first or fourth co-ordinates, between -pi/2 to +pi/2. atan2() can give an angle between 0 and 2pi (will include 0, but not 2pi).

We are currently in a feature freeze awaiting the next release; we are supposed to be just doing bug fixes at this point, but one of us developers might slip it in. If not, I can slip it into the first beta after the release.

Ummm...

The AutoIT ATan() function gives the angle in radians for the ratio of Opp/adj sides. I had to look this forgotten trig stuff up (Google truly is your friend), and ask my son (who is taking trig) to get this working. This script takes manual input for X and Y as signed integers and returns the angle (Theta) after converting to degrees. I did X and Y as integers instead of floating point because the point was to calculate angles from mouse coordinates relative to a predefined origin:

Plain Text        expandcollapse  popup

; Test calculate Theta from cartesean coordinates

Dim Const $Pi = 4 * ATan(1)

$x = InputBox("Trig Test", "Enter value for X: ")
If Not StringIsInt($x) Then
    MsgBox(16, "Trig Test", "Invalid value for X!")
    Exit
EndIf

$y = InputBox("Trig Test", "Enter value for value for Y: ")
If Not StringIsInt($y) Then
    MsgBox(16, "Trig Test", "Invalid Y!")
    Exit
EndIf

$r = Sqrt(($x ^ 2) + ($y ^ 2))

MsgBox(32, "Trig Test", "Using the following values:" & @CRLF & _
        "Const Pi: " & $Pi & @CRLF & _
        "Input X: " & $x & @CRLF & _
        "Input Y: " & $y & @CRLF & _
        "Calculated R: " & $r)

Select
    Case $x = 0 And $y = 0
        $Theta = 0
        
    Case $x >= 0 And $y >= 0; +x/+y = 0-90deg
        $Theta = ATan($x / $y) * 180 / $Pi
        
    Case $x >= 0 And $y < 0; +x/-y = 90-180deg
        $Theta = (ATan(Abs($y) / $x) * 180 / $Pi) + 90
        
    Case $x < 0 And $y < 0; -x/-y = 180-270deg
        $Theta = (ATan(Abs($x) / Abs($y)) * 180 / $Pi) + 180
        
    Case $x < 0 And $y >= 0; -x/+y = 2700-360deg
        $Theta = (ATan($y / Abs($x)) * 180 / $Pi) + 270
EndSelect

MsgBox(32, "Trig Test", "Theta = " & $Theta)

Had to decalcify some old brain cells to do this... good exercise!

[PsaltyDS]

Modified my script into a reusable function: _xy2polar($x, $y), where $x and $y are x/y coordinates, and it returns a three element array where:

[0] = calculated radius
[1] = calculated Theta (in radians)
[2] = calculated Theta (in degrees)

If you want to get 360deg functionality, you have to be aware of signed x/y values:

0,0 = center
0, +y = 0deg
+x, 0 = 90deg
0, -y = 180deg
-x, 0 = 270deg

My shot at this is _xy2polar():

CODE

; Test _xy2polar() UDF
; PsaltyDS at AutoIT forums, 2006-01-26

While (1)
$InputX = InputBox("Trig Test", "Enter value for X: ")
If $InputX = "" Then Exit
$InputY = InputBox("Trig Test", "Enter value for value for Y: ")
If $InputY = "" Then Exit
$Results = _xy2polar($InputX, $InputY)
$SavError = @error
If IsArray($Results) Then
If MsgBox(32 + 1, "Function _xy2polar()", "Using the following inputs:" & @CRLF & _
@TAB & "X = " & $InputX & @CRLF & _
@TAB & "Y = " & $InputY & @CRLF & @CRLF & _
"Calculated the following values:" & @CRLF & _
@TAB & "R = " & $Results[0] & @CRLF & _
@TAB & "Theta(Radians) = " & $Results[1] & @CRLF & _
@TAB & "Theta(Degrees) = " & $Results[2]) = 2 Then ExitLoop
Else
MsgBox(16, "XY-2-Polar Error", "Error returned from _xy2polar() function, @Error = " & $SavError)
EndIf
WEnd

; User Declared Function (UDF) _xy2polar() - calculates polar coordinates (r, Theta) from cartesean (x, y) coordinates
; Usage: _xy2polar($x, $y) where: $x and $y are signed X and Y coordinates (int or float) with a 0,0 center
; Returns: Three element one-dimensional array where:
; [0] = Calculated radius from 0,0
; [1] = Theta angle in radians, 0 <= Theta < 2(Pi)
; [2] = Theta angle in degrees, 0 <= Theta < 360
; On error: Returns "", and @error = 1

Func _xy2polar($x, $y)
$Pi = 4 * ATan(1)
If StringIsInt($x) Or StringIsFloat($x) Then
If StringIsInt($y) Or StringIsFloat($y) Then
; OK
Else
SetError(1)
Return ""
EndIf
Else
SetError(1)
Return ""
EndIf
Dim $PolarAnswer[3] ; $Results[0]=Radius, [1]=Theta (in Radians), [2]=Theta (in Degrees)
$r = Sqrt(($x ^ 2) + ($y ^ 2))
$PolarAnswer[0] = $r
Select
Case $x = 0 And $y = 0
$ThetaRad = 0
$ThetaDeg = 0
Case $x >= 0 And $y >= 0 ; +x/+y = 0-90deg quadrant
$ThetaRad = ATan($x / $y)
$ThetaDeg = $ThetaRad * 180 / $Pi
Case $x >= 0 And $y < 0 ; +x/-y = 90-180deg quadrant
$ThetaRad = ATan(Abs($y) / $x)
$ThetaDeg = $ThetaRad * 180 / $Pi + 90
$ThetaRad = $ThetaRad + $Pi / 2
Case $x < 0 And $y < 0 ; -x/-y = 180-270deg quadrant
$ThetaRad = ATan(Abs($x) / Abs($y))
$ThetaDeg = $ThetaRad * 180 / $Pi + 180
$ThetaRad = $ThetaRad + $Pi
Case $x < 0 And $y >= 0 ; -x/+y = 2700-360deg quadrant
$ThetaRad = ATan($y / Abs($x))
$ThetaDeg = $ThetaRad * 180 / $Pi + 270
$ThetaRad = $ThetaRad + 3 * $Pi / 2
EndSelect
$PolarAnswer[1] = $ThetaRad
$PolarAnswer[2] = $ThetaDeg
SetError(0)
Return $PolarAnswer
EndFunc ;==>_xy2polar

I'm pretty new with AutoIT, and would love to hear pointers/critiques.

Edit: Tweaked comments to explain usage and removed redundant declaration of Pi.

Edited by PsaltyDS, 26 January 2006 - 05:36 PM.

[Gabburd]

Just in case anyone still needs this, here's what I ended up with:

Func ATan2($x, $y)
    Local Const $PI = 3.14159265358979
    If $y < 0 Then
        Return -ATan2($x, -$y)
    ElseIf $x < 0 Then
        Return $Pi - ATan(-$y / $x)
    ElseIf $x > 0 Then
        Return ATan($y / $x)
    ElseIf $y <> 0 Then
        Return $Pi / 2
    Else
        MsgBox( 16, "Error - Division by zero", "Domain Error in Function: ATan2()" & @LF & "$x and $y cannot both equal zero" )
        SetError( 1 )
    EndIf
EndFunc

[GEOSoft]

Just in case anyone still needs this, here's what I ended up with:

Func ATan2($x, $y)
    Local Const $PI = 3.14159265358979
    If $y < 0 Then
        Return -ATan2($x, -$y)
    ElseIf $x < 0 Then
        Return $Pi - ATan(-$y / $x)
    ElseIf $x > 0 Then
        Return ATan($y / $x)
    ElseIf $y <> 0 Then
        Return $Pi / 2
    Else
        MsgBox( 16, "Error - Division by zero", "Domain Error in Function: ATan2()" & @LF & "$x and $y cannot both equal zero" )
        SetError( 1 )
    EndIf
EndFunc

Much shorter than the existing _ATan2() (in Math.au3) anyway. Of course the original also has some extra error checking in it.

[Gabburd]

Wow, I must be blind not to have noticed that there already was a function in there.
I think I'll switch to using it, as you said it has more error checking.