David L Goldsmith wrote: > PS: The Python built in function (i.e., you don't even need numpy for > this) abs(x) is "vectorized" (i.e., accepts a (nested) sequence, incl. > numpy array, argument) and overloaded to give the modulus (i.e., > Pythagorean "length") of a complex number when such is its argument. > This isn't quite right. The built in abs function looks for the special method __abs__. So, abs(x) is equivalent to x.__abs__(). Arrays supply an appropriate __abs__ method, lists do not. For example:
>>> l = [1,2,3,4] >>> abs(l) Traceback (most recent call last): File "<stdin>", line 1, in ? TypeError: bad operand type for abs() >>> a = numpy.arange(5) >>> abs(a) array([0, 1, 2, 3, 4]) -tim > DG > > Kenny Ortmann wrote: > >> excuse my laziness for not looking this up, I googled it but could not find >> a solution. >> matlab has a >> isreal(array) >> where if the array is full of real numbers the value returned is 1. >> I'm translating matlab code and ran across >> >> if ~isreal(array) >> array = abs(array) >> >> Is there a way to check to see if a number is real or complex? and if so is >> there a way to extract the(a + ib) because the absolute value of a complex >> number is like the pythagorean therom on a and b? >> >> thanks for your help, >> Kenny >> >> >> >> ------------------------------------------------------------------------- >> Take Surveys. Earn Cash. Influence the Future of IT >> Join SourceForge.net's Techsay panel and you'll get the chance to share your >> opinions on IT & business topics through brief surveys -- and earn cash >> http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV >> _______________________________________________ >> Numpy-discussion mailing list >> Numpy-discussion@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/numpy-discussion >> >> > > > ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Numpy-discussion mailing list Numpy-discussion@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/numpy-discussion
