Thanks Dan. Great help

but my problem has not solved yet

This doesn't work for type ((Float -> Float)->Bool)

to make it easier ignore the rotation and suppose I want just multiplay with whatever (x ,y) and return the result to this type ((Float -> Float)->Bool)

note this type is shorten and replace by t

Type Point = (Float, Float)

Type Bitmap = Point -> Bool

so the function type actually

func :: Bitmap -> Float -> Bitmap

I want to take Bitmap do some calculation on Bitmap the return it as Bitmap.

GHCi response for Dan method is this

Couldn't match expected type `Bitmap'

against inferred type `(a, b)'

so it is missing a Bool.

hopefully it is clear .

On Mon, Apr 19, 2010 at 7:02 PM, Dan Weston <westondan@imageworks.com> wrote:

First of all, your function

func (x,y) s dg =((x*(cos dg) - y*(sin dg)),(x*(sin dg) - y*(cos dg)))
does NOT work for type (Float -> Float), unless you mean that that is the type of the unused parameter s. Also, your desired type ((Float -> Float) -> Bool) itself looks suspicious. It must accept any function (without something to apply it to) and arbitrarily return True or False. How will you decide which? I suspect you need another parameter for this function.

Second, on the off chance you are trying to calculate the position on a circle scaled then rotated an angle dg from (x,y), that new position is

f (x,y) s dg = (s*(x*(cos dg) - y*(sin dg)),s*(x*(sin dg) + y*(cos dg)))

in which case you are missing the s and the last minus sign in your formula should be a plus sign.
If so, this can be evaluated with greater clarity (and probably accuracy) in polar coordinates:

g (x,y) s dg = (r * cos a, r * sin a)
where r = s * sqrt (x^2 + y^2)
a = atan2 y x + dg

Third, if you did not need the scale, I would use an underscore to make that clear:

h (x,y) _ dg = (r * cos a, r * sin a)
where r = sqrt (x^2 + y^2)
a = atan2 y x + dg

That's all the observations I can make unless you describe the problem more clearly. Sorry.

Dan

Mujtaba Boori wrote:

sorry
ok I am trying to make these calculation
func (x,y) s dg =((x*(cos dg) - y*(sin dg)),(x*(sin dg) - y*(cos dg)))

This work for type (Float -> Float)

but how can make it work with ((Float -> Float) -> Bool)

because my main function that I want use with. it takes (Float,Float) ->Bool) I need to return the same type ((Float,Float) ->Bool) so it could be used with other function.

On Mon, Apr 19, 2010 at 5:54 PM, Ozgur Akgun <ozgurakgun@gmail.com <mailto:ozgurakgun@gmail.com>> wrote:

Can you at least give an example of how you intend to use this "func"?
Since you do not describe it's behaviour, it is very hard to make a
useful
comment (at least for me)

Best,

On 19 April 2010 16:54, Mujtaba Boori <mujtaba.boori@gmail.com
<mailto:mujtaba.boori@gmail.com>> wrote:
>
> Hello
> I am sorry for the silly question.
>
> I have a function as the following
> func:: ((Float,Float) ->Bool) -> Float -> ((Float,Float) -> Bool)
> I am trying to make calculation in this type ((Float,Float)
->Bool) with Float and then pass the information to ((Float,Float)
-> Bool)
>
> Thank again appreciated.
> _______________________________________________
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> Haskell-Cafe@haskell.org <mailto:Haskell-Cafe@haskell.org>

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>

--
Ozgur Akgun

--
Mujtaba Ali Alboori

--
Mujtaba Ali Alboori