[Numpy-discussion] objects are not aligned. Matrix and Array
Wayne Watson
sierra_mtnview at sbcglobal.net
Sat Dec 19 01:20:21 EST 2009
Is math automatic (built-in)?
Same result with np.dot(m2, m1).
Ah, this works. dotres = np.dot(m2.T, m1).
It looks to me like the shapes are the same, so maybe dot() requires one
as a column vector and one as a row.
Thanks.
Charles R Harris wrote:
>
>
> On Fri, Dec 18, 2009 at 10:20 PM, Wayne Watson
> <sierra_mtnview at sbcglobal.net <mailto:sierra_mtnview at sbcglobal.net>>
> wrote:
>
> This program gives me the message following it:
> ================Program==========
> import numpy as np
> from numpy import matrix
> import math
>
>
> You don't want math.
>
>
> def sinD(D): # given in degrees, convert to radians
> return math.sin(math.radians(D))
> def cosD(D):
> return math.cos(math.radians(D))
>
>
> def sinD(D):
> return np.sin(np.deg2rad(D))
>
>
> r = math.sqrt(2*2+5*5)
>
>
> np.hypot(2, 5)
>
>
> print r
> m1 = matrix([[2], [5]])
> print "m1: ", m1
>
> theta = 5.0 # degrees
> #CW 2x2 clockwise matrix
> rotCW = matrix([ [cosD(theta), sinD(theta)], [-sinD(theta),
> cosD(theta)] ])
>
> print rotCW
>
> m2 = rotCW*m1
> print "m2: ", m2
> print "aaaaaaaa: ", type(m1), type(m2)
> m1=np.array(m1)
> m2=np.array(m2)
>
> print "zzzzzzzz: ", type(m1), type(m2)
>
> print"dot, ..."
> dotres = np.dot(m1,m2)
>
>
> Try np.dot(m2, m1), m1 is a column matrix.
>
>
> print "dotres", dotres
> ==============end==========
>
> ==========Output msgs========
> 5.38516480713
> m1: [[2]
> [5]]
> [[ 0.9961947 0.08715574]
> [-0.08715574 0.9961947 ]]
> m2: [[ 2.42816811]
> [ 4.806662 ]]
> aaaaaaaa: <class 'numpy.core.defmatrix.matrix'> <class
> 'numpy.core.defmatrix.matrix'>
> zzzzzzzz: <type 'numpy.ndarray'> <type 'numpy.ndarray'>
> dot, ...
>
> Traceback (most recent call last):
> File
> "C:/Sponsor_Meteors/Sentinel_Development/Development_Sentuser+Utilities/Playground/junk.py",
> line 30, in <module>
> dotres = np.dot(m1,m2)
> ValueError: objects are not aligned
> ================end msgs===========
> Why the msg? The types look alike and each array/matrix contains two
> elements..
>
>
> Chuck
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> NumPy-Discussion mailing list
> NumPy-Discussion at scipy.org
> http://mail.scipy.org/mailman/listinfo/numpy-discussion
>
--
Wayne Watson (Watson Adventures, Prop., Nevada City, CA)
(121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time)
Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet
"... humans'innate skills with numbers isn't much
better than that of rats and dolphins."
-- Stanislas Dehaene, neurosurgeon
Web Page: <www.speckledwithstars.net/>
More information about the NumPy-Discussion
mailing list