dirbax Posted February 28, 2009 Share Posted February 28, 2009 Hi , I am working on some math stuff and I need to check some points , so are theses formulas correct ? ISZ(x) : is it 0 ? isz (x) = cos ( pi * ( (2*ceil( abs(x) ) + 1)) / 2 ) / cos(1) Ins : Real number x Out : 1 if x=0 , 0 if x <> 0 --------------------------------------------------------------- SGN(x) : Sign sgn(x) = abs(x) / ( x + isz(x) ) Ins : Real number x Out : 1 if x>0 , 0 if x = 0 , -1 if x < 0 more here Dirbax thanks Link to comment Share on other sites More sharing options...
the tree Posted February 28, 2009 Share Posted February 28, 2009 Well yes. But... why? Link to comment Share on other sites More sharing options...
dirbax Posted February 28, 2009 Author Share Posted February 28, 2009 I am trying to create a new math branch DIMD Link to comment Share on other sites More sharing options...
the tree Posted February 28, 2009 Share Posted February 28, 2009 But things like the sign function and the dirac delta function... already exist. Link to comment Share on other sites More sharing options...
dirbax Posted February 28, 2009 Author Share Posted February 28, 2009 Yes but I still should mention them since I am making the basis of DIMD, an other point is trying to avoid semantic presentation of functions such as this and go for smooth calculations Link to comment Share on other sites More sharing options...
the tree Posted February 28, 2009 Share Posted February 28, 2009 For one abs() isn't smooth, at all, neither is ceiling(). And why don't you want the way a function is presented to be semantic? It's not like you're saving on computability, trig functions are clearly more expensive than a check for properties that are written into the way a number is stored. Link to comment Share on other sites More sharing options...
dirbax Posted March 1, 2009 Author Share Posted March 1, 2009 For one abs() isn't smooth, at all, neither is ceiling(). True , I am still working on it in order to minimise the number of functions such as ceil and abs which use semantic definition . Link to comment Share on other sites More sharing options...
the tree Posted March 1, 2009 Share Posted March 1, 2009 Again, what's wrong with a semantic definition? If makes things possible to read, as well as computationally cheaper, what could possibly be wrong with it? Merged post follows: Consecutive posts mergedAnd it just occurred to me, if you're trying to define discontinuous functions as compositions of continuous ones, it can't be done. Link to comment Share on other sites More sharing options...
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