Place the following in your home directory at ~/.numpy-site.cfg in order to install numpy with openblas support

.numpy-site.cfg

# Place the following in your home directory at ~/.numpy-site.cfg 
# in order to install numpy with openblas support


[openblas]
libraries = openblas
library_dirs = /usr/local/opt/openblas/lib
include_dirs = /usr/local/opt/openblas/include

fastdot.py

# Copyright (c) Huy Nguyen 2013
# All rights reserved.
# 
# Redistribution and use in source and binary forms, with or without modification,
# are permitted provided that the following conditions are met:
# 
# * Redistributions of source code must retain the above copyright notice, this
#   list of conditions and the following disclaimer.
# 
# * Redistributions in binary form must reproduce the above copyright notice, this
#   list of conditions and the following disclaimer in the documentation and/or
#   other materials provided with the distribution.
# 
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
# ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

def _force_forder(x):
    """
    Converts arrays x to fortran order. Returns
    a tuple in the form (x, is_transposed).
    """
    if x.flags.c_contiguous:
        return (x.T, True)
    else:
        return (x, False)
        
def dot(A,B):
    """
    Uses blas libraries directly to perform dot product
    """
    from scipy import linalg
    
    A, trans_a = _force_forder(A)
    B, trans_b = _force_forder(B)
    gemm_dot = linalg.get_blas_funcs("gemm", arrays=(A,B))
    
    # gemm is implemented to compute: C = alpha*AB  + beta*C
    return gemm_dot(alpha=1.0, a=A, b=B, trans_a=trans_a, trans_b=trans_b)
    

I have tried to run your fastdot code but am receiving an error (works fine with 2-tensors but not for 3-tensors). Once I edit the site.cfg file am I supposed to do something else (I suspect my openblas is not correctly synced with numpy)?