New issue 1214: vector annotation of off-axis plot generates inconsistent result https://bitbucket.org/yt_analysis/yt/issues/1214/vector-annotation-of-off-axis-plot

Suoqing Ji:

Test dataset is [here](https://dl.dropboxusercontent.com/u/83265784/data.npy)

Test script:

``` #!python

import yt import numpy as np

dims = (200,200,200)

x = np.load('data.npy')

field1 = x[:,2].reshape(dims, order="F") field2 = x[:,1].reshape(dims, order="F") field3 = x[:,0].reshape(dims, order="F")

data = dict(velocity_x = field1,

velocity_y = field2,
velocity_z = field3)

bbox = np.array([[-100, 99], [-100, 99], [-100, 99]])

ds = yt.load_uniform_grid(data, dims, ‘km’, bbox=bbox, nprocs=1)

L = [0, -1, 0] north_vector = [0, 0, 1] slc1 = yt.OffAxisSlicePlot(ds, L, ‘velocity_x’, center=[0,0,0], width=(180,'km'), north_vector=north_vector) slc1.annotate_velocity(factor=40, normalize=True) slc1.save()

L = [0, 1, 0] north_vector = [0, 0, 1] slc2 = yt.SlicePlot(ds, L, ‘velocity_x’, center=[0,0,0], width=(180,'km'), north_vector=north_vector) slc2.annotate_velocity(factor=40, normalize=True) slc2.save() ```

On-axis plot:


Off-axis plot: