VB Trig Problem

[Ahriman]

i need to take the sin of an angel in degrees but VB does it in radians

so, how do i get VB to calculate trig functions in degrees instead of radians?

[Good Dreams]

Pi= 3.141592654

AngleR = AngleD * Pi / 180

AngleD = AngleR * 180 / Pi

[Ahriman]

i don't understand how i am supposed to use that code

this is what i got:

a is the angle in degrees
s is the initian speed of the object
dh is really dh/dt, the rate of change of the height of the object with respect to time

a=45
dh=sin(a)*s

i need that dh (dh/dt) value for a formula,
my problem is it calculates sin(45) as .850935 when sin(45) in degrees is .7071

[parksie]

Convert the angle to radians THEN pass it to the trig functions. VB, like most things you'll encounter, uses radians because they are a much more practical type (they're based on REAL properties of a circle as opposed to the "hey, let's have 360 degrees in this thing" method)

[Good Dreams]

AngleD is the angle in degrees and AngleR in Radians

Type:
dh=sin(a * Pi / 180) * s

[parksie]

Function Deg2Rad(dAngle As Double)
    Deg2Rad = dAngle * (Pi / 180)
End Function

...

Debug.Print Sin(Deg2Rad(45))

[Good Dreams]

Originally posted by parksie

Function Deg2Rad(dAngle As Double)
    Deg2Rad = dAngle * (Pi / 180)
End Function

...

The parentisis aren't needed: Deg2Rad = dAngle * Pi / 180

It doesn't really matter...

[parksie]

Yeah, but I put them in because in my code I usually define the constant PIDIV180 to save VB having to recalculate it each time

[Active]

If you don't have a good memory of the value of pi
like me use...

Pi = 4*Atn(1)

[Ahriman]

thanks guys, that code did the trick

my prog. works fine now