Date: Thu, 6 Feb 2014 08:42:38 -0800

From: Chris Barker <chris.barker@noaa.gov> Subject: Re: [Numpy-discussion] create numerical arrays from strings To: Discussion of Numerical Python <numpy-discussion@scipy.org> Message-ID: < CALGmxEKVNQok6wtY-jbjzgaeU5ewHh1_FLmSQXJsUJfcLExh2w@mail.gmail.com> Content-Type: text/plain; charset="utf-8"

1) so use np.mat !

To elaborate on this (because I, for one, was not aware that mat supported this API, and, significantly, the fact that it does, does not appear in its docstring: import numpy as np help(np.mat) Help on function asmatrix in module numpy.matrixlib.defmatrix: asmatrix(data, dtype=None) Interpret the input as a matrix. Unlike `matrix`, `asmatrix` does not make a copy if the input is already a matrix or an ndarray. Equivalent to ``matrix(data, copy=False)``. Parameters ---------- data : array_like Input data. Returns ------- mat : matrix `data` interpreted as a matrix. Examples -------- >>> x = np.array([[1, 2], [3, 4]]) >>> m = np.asmatrix(x) >>> x[0,0] = 5 >>> m matrix([[5, 2], [3, 4]]) ) However, we do have: a=np.mat('1 2;3 4') a matrix([[1, 2], [3, 4]]) b = np.array(a) b array([[1, 2], [3, 4]]) and so, as we should expect: c=np.array(np.mat('1 2;3 4')) c array([[1, 2], [3, 4]]) So the substance of the utility function Stefan suggests is one line: def numstr2numarr(in): """ 'in' is a matlab-style array containing strings for the numerical array entries """ return np.array(np.mat(in)) In essence, numpy "almost" provides the API you're asking for. DG