brl_math.md 9.4 KB
id: brl.math title: BRL.Math
sidebar_label: BRL.Math
Functions
Function IsNan( x:Double )
Check if a value is NAN
Returns
True if x is 'not a number' (eg: Sqr(-1))
Example 1
SuperStrict
For Local f:Float=-0.4 Until 0.4 Step 0.2
If IsNan(Sqr(f)) = True Then
Print "Square Root of "+f+" is not a real number"
Else
Print "Square Root of "+f+" = "+Sqr(f)
EndIf
Next
' ===================
' Output
' Square Root of -0.400000006 is not a real number
' Square Root of -0.200000003 is not a real number
' Square Root of 0.000000000 = 0.00000000000000000
' Square Root of 0.200000003 = 0.44721359883195888
Example 2
SuperStrict
For Local f:Float = - 0.4 Until 0.4 Step 0.2
If IsInf(Log(f) ) Then
Print "Log(" + f + ")=Infinity "+Log(f)
Else If IsNan(Log(f) ) Then
Print "Log(" + f + ") is not a real number "+Log(f)
Else
Print "Log(" + f + ")=" + Log(f)
End If
Next
' ===================
' Output
' Log(-0.400000006) is not a real number -1.#IND000000000000
' Log(-0.200000003) is not a real number -1.#IND000000000000
' Log(0.000000000)=Infinity -1.#INF000000000000
' Log(0.200000003)=-1.6094378975329393
Function IsInf( x:Double )
Check if a value is infinite (eg: 1.0/0.0)
Returns
True if x is infinite
Example 1
SuperStrict
For Local f:Float=-0.4 Until 0.4 Step 0.2
If IsInf(1.0 / f) = True Then
Print "Divide by Zero"
Else
Print "inverse of "+f+" = "+String(1.0/f)
EndIf
Next
' ===================
' Output
' inverse of -0.400000006 = -2.50000000
' inverse of -0.200000003 = -5.00000000
' Divide by Zero
' inverse of 0.200000003 = 5.00000000
Example 2
SuperStrict
For Local f:Float = - 0.4 Until 0.4 Step 0.2
If IsInf(Log(f) ) Then
Print "Log(" + f + ")=Infinity "+Log(f)
Else If IsNan(Log(f) ) Then
Print "Log(" + f + ") is not a real number "+Log(f)
Else
Print "Log(" + f + ")=" + Log(f)
End If
Next
' ===================
' Output
' Log(-0.400000006) is not a real number -1.#IND000000000000
' Log(-0.200000003) is not a real number -1.#IND000000000000
' Log(0.000000000)=Infinity -1.#INF000000000000
' Log(0.200000003)=-1.6094378975329393
Function Sqr:Double( x:Double )
Square root of x
Example
'IsNan (Not a Number)
SuperStrict
For Local f:Float=-0.4 Until 0.4 Step 0.2
If IsNan(Sqr(f)) = True Then
Print "Square Root of "+f+" is not a real number"
Else
Print "Square Root of "+f+" = "+Sqr(f)
EndIf
Next
' ===================
' Output
' Square Root of -0.400000006 is not a real number
' Square Root of -0.200000003 is not a real number
' Square Root of 0.000000000 = 0.00000000000000000
' Square Root of 0.200000003 = 0.44721359883195888
Function Sin:Double( x:Double )
Sine of x degrees
Example 1
Rem
Sin:Double( x:Double )
End Rem
SuperStrict
For Local d:Int = 0 To 360 Step 45
Print "Sin("+d+")="+Sin(d)
Next
Example 2
SuperStrict
Graphics 640,480
SetColor 128,128,128
DrawRect 0,240,360,1
SetColor 0,255,255
For Local t:Int=0 To 359
Plot t,Float(240+Sin(t)*80)
Next
Flip
Repeat
WaitKey()
Until KeyDown(KEY_ESCAPE)
Example 3
SuperStrict
Graphics 640,480
Local radius:Int=80
SetColor 0,255,255
For Local t:Int=0 To 359 Step 4
Plot Float(320+Sin(t)*radius), Float(240+Cos(t)*radius)
Next
Flip
Repeat
WaitKey()
Until KeyDown(KEY_ESCAPE)
Function Cos:Double( x:Double )
Cosine of x degrees
Example 1
Rem
Cosine of x
End Rem
SuperStrict
For Local d:Int = 0 To 360 Step 45
Print "Cos("+d+")="+Cos(d)
Next
Example 2
SuperStrict
Graphics 640,480
SetColor 128,128,128
DrawRect 0,240,360,1
SetColor 0,255,255
For Local t:Int=0 To 359
Plot t,Float(240+Cos(t)*80)
Next
Flip
Repeat
WaitKey()
Until KeyDown(KEY_ESCAPE)
Example 3
'
' How to draw a 'dotted' flower using Sin/Cos
'
SuperStrict
Graphics 640,480
Local radius:Int
SetColor 0,255,255
For Local t:Int=0 To 359 Step 4
radius=Sin(t*8)*40+80
Plot Float(320+Sin(t)*radius), Float(240+Cos(t)*radius)
Next
Flip
Repeat
WaitKey()
Until KeyDown(KEY_ESCAPE)
Function Tan:Double( x:Double )
Tangent of x degrees
Example
Rem
Tangent of x degrees
End Rem
SuperStrict
For Local d:Int = 0 To 360 Step 45
Print "Tan("+d+")="+Float(Tan(d))
Next
Function ASin:Double( x:Double )
Inverse Sine of x
Example
Rem
Inverse Sine of x
End Rem
SuperStrict
For Local d:Double = -1.0 To 1.0 Step 0.125
Print "ASin("+d+")="+ASin(d)
Next
Function ACos:Double( x:Double )
Inverse Cosine of x
Example
Rem
Inverse Cosine of x
End Rem
SuperStrict
For Local d:Double = -1.0 To 1.0 Step 0.125
Print "ACos("+d+")="+ACos(d)
Next
Function ATan:Double( x:Double )
Inverse Tangent of x
Example
Rem
ATan returns the Inverse Tangent of x
End Rem
SuperStrict
For Local d:Double = -1.0 To 1.0 Step 0.125
Print "ATan("+d+")="+ATan(d)
Next
Function ATan2:Double( y:Double,x:Double )
Inverse Tangent of two variables x , y
Example 1
Rem
ATan2 returns the Inverse Tangent of two variables
End Rem
SuperStrict
Function Angle:Double(x0:Double,y0:Double,x1:Double,y1:Double)
Return ATan2(y1-y0,x1-x0)
End Function
Graphics 640,480
While Not KeyHit(KEY_ESCAPE)
Cls
Local x:Float = MouseX()
Local y:Float = MouseY()
DrawLine 320,240,x,y
DrawText "Angle="+Angle(320,240,x,y),20,20
Flip
Wend
Example 2
'
' ATan2
'
' returns the angle in degrees between two points by giving the width and height between then.
'
SuperStrict
Print ATan2(4,4)
'4^| / (45 degrees)
' | /
' | /
' | /
' |/
' +-----
' 4>
Function Sinh:Double( x:Double )
Hyperbolic sine of x
Example
'
' Sinh Hyperbolic Sine
'
SuperStrict
Graphics 640,480
For Local t:Float=-7To 7 Step .1
Plot 100+t*10,Float(240+Sinh(t))
Next
Flip
Repeat Until KeyDown(KEY_ESCAPE) Or AppTerminate()
Function Cosh:Double( x:Double )
Hyperbolic cosine of x
Example
'
' Cosh Hyperbolic Cosine
'
SuperStrict
Graphics 640,480
For Local t:Float = - 7To 7 Step .1
SetColor 255,0,0 'red cosh
Plot 100 + t * 10 , Float(240 + Cosh(t))
SetColor 0,255,255
Plot 200 + t * 10 , Float(240 + Sinh(t))
Next
Flip
Repeat Until KeyDown(KEY_ESCAPE) Or AppTerminate()
Function Tanh:Double( x:Double )
Hyperbolic tangent of x
Example
'
' Tanh Hyperbolic Cosine
'
SuperStrict
Graphics 640,480
For Local t:Float = -.2 To .2 Step .001
SetColor 255,0,0 'red cosh
Plot 100 + t * 500 , Float(240 + Tanh(t)*500)
Print t*500+":"+Tanh(t)*500
Next
Flip
Repeat Until KeyDown(KEY_ESCAPE) Or AppTerminate()
Function Exp:Double( x:Double )
Exponential function
Example
'
' Exponential
'
SuperStrict
Graphics 640,480
For Local t:Float = - 7 To 7 Step .1
Plot 100 + t * 10 , Float(240 - Exp(t))
Print Exp(t)
Next
Flip
Repeat Until KeyDown(KEY_ESCAPE) Or AppTerminate()
Function Log:Double( x:Double )
Natural logarithm
Example
Rem
Log(n#) returns the natural logarithm of n
End Rem
SuperStrict
For n:Float = 1 To 20
Print "Log("+n+")="+Log(n)
Next
Function Log10:Double( x:Double )
Base 10 logarithm
Example
Rem
Log10(n#) returns the Base 10 logarithm of n
End Rem
SuperStrict
For Local n:Float = 0 To 100 Step 10
Print "Log10("+n+")="+Log10(n)
Next
Function Ceil:Double( x:Double )
Smallest integral value not less than x
Example 1
Rem
Ceil(x#) returns the smallest integral value not less than x
End Rem
SuperStrict
For Local i:Float = -1 To 1 Step .2
Print "Ceil("+i+")="+Ceil(i)
Next
Example 2
SuperStrict
Graphics 640,480
Local x:Int,y:Int
Local mx:Int,my:Int
HideMouse
Repeat
mx=MouseX()
my=MouseY()
Cls
' draw grid
SetColor 90,90,90
For y=0 Until 480 Step 20
For x=0 Until 640 Step 20
Plot x,y
Next
Next
'draw mouse mx,my
SetColor 255,255,255
DrawRect mx-1,my-1,3,3
' draw ceiled and floored mouse mx,my
SetColor 255,255,0
DrawRect Float(Ceil( mx/20.0)*20-1),Float(Ceil(my/20.0)*20-1),3,3
SetColor 0,255,255
DrawRect Float(Floor(mx/20.0)*20-1),Float(Floor( my/20.0)*20-1),3,3
Flip
Until KeyDown(KEY_ESCAPE)
Function Floor:Double( x:Double )
Largest integral value not greater than x
Example 1
Rem
Floor(x!) returns the largest integral value not greater than x
End Rem
SuperStrict
For Local i:Double = -1 To 1 Step .2
Print "Floor("+i+")="+Floor(i)
Next
Example 2
SuperStrict
Graphics 640,480
Local x:Int,y:Int
Local mx:Int,my:Int
HideMouse
Repeat
mx=MouseX()
my=MouseY()
Cls
' draw grid
SetColor 90,90,90
For y=0 Until 480 Step 20
For x=0 Until 640 Step 20
Plot x,y
Next
Next
'draw mouse mx,my
SetColor 255,255,255
DrawRect mx-1,my-1,3,3
' draw ceiled and floored mouse mx,my
SetColor 255,255,0
DrawRect Float(Ceil( mx/20.0)*20-1),Float(Ceil(my/20.0)*20-1),3,3
SetColor 0,255,255
DrawRect Float(Floor(mx/20.0)*20-1),Float(Floor( my/20.0)*20-1),3,3
Flip
Until KeyDown(KEY_ESCAPE)