title: How to solve CUDA PATH Error?
body: <p>I recently installed NVIDIA CUDA and test run a code :</p>
  
  <pre><code>from numba import cuda
  from numba import *
  import numpy as np
  from pylab import imshow, show
  from timeit import default_timer as timer
  </code></pre>
  
  <p>But I got this error in ubuntu 16.0.4. How can I resolve this error:</p>
  
  <pre><code>@cuda.jit(argtypes=[f8, f8, f8, f8, uint8[:,:], uint32])
    File "/usr/local/lib/python2.7/dist-packages/numba/cuda/decorators.py", line 92, in kernel_jit
      kernel.bind()
    File "/usr/local/lib/python2.7/dist-packages/numba/cuda/compiler.py", line 489, in bind
      self._func.get()
    File "/usr/local/lib/python2.7/dist-packages/numba/cuda/compiler.py", line 366, in get
      cuctx = get_context()
    File "/usr/local/lib/python2.7/dist-packages/numba/cuda/cudadrv/devices.py", line 194, in get_context
      return _runtime.get_or_create_context(devnum)
    File "/usr/local/lib/python2.7/dist-packages/numba/cuda/cudadrv/devices.py", line 162, in get_or_create_context
      return self.push_context(self.gpus[devnum])
    File "/usr/local/lib/python2.7/dist-packages/numba/cuda/cudadrv/devices.py", line 40, in __getitem__
      return self.lst[devnum]
    File "/usr/local/lib/python2.7/dist-packages/numba/cuda/cudadrv/devices.py", line 26, in __getattr__
      numdev = driver.get_device_count()
    File "/usr/local/lib/python2.7/dist-packages/numba/cuda/cudadrv/driver.py", line 307, in get_device_count
      self.cuDeviceGetCount(byref(count))
    File "/usr/local/lib/python2.7/dist-packages/numba/cuda/cudadrv/driver.py", line 248, in __getattr__
      self.initialization_error)
  CudaSupportError: Error at driver init: 
  
  CUDA driver library cannot be found.
  If you are sure that a CUDA driver is installed,
  try setting environment variable NUMBA_CUDA_DRIVER
  with the file path of the CUDA driver shared library.
  </code></pre>