我正在尝试使用map_blocks API并行处理dask数组的方位角求和。我的代码如下：
import numpy as np
import xarray as xr
import dask.array as dsar
from dask.diagnostics import ProgressBar
N = 2**7
da = xr.DataArray(np.linspace(0.,1.,N*2)[:,np.newaxis,np.newaxis]
+(np.arange(-N/2,N/2)**2)[np.newaxis,:,np.newaxis]
+(np.arange(-N/2,N/2)**2)[np.newaxis,np.newaxis,:],
dims=['time','x','y'],
coords={'time':range(N*2),'x':np.arange(-N/2,N/2),'y':np.arange(-N/2,N/2)}
).chunk({'time':1})
R = np.sqrt(da.x.data[np.newaxis,:]**2 + da.y.data[:,np.newaxis]**2)
nfactor = 4
nbins = int(len(R)/nfactor)
r = np.linspace(0.,da.x.data.max(),nbins)
ridx = np.digitize(np.ravel(R), r)
area = np.bincount(ridx)
axes=[-1,-2]
M = [da.shape[n] for n in axes]
data = da.data.reshape((N*2,np.prod(M)))
with ProgressBar():
azisum = dsar.map_blocks(np.bincount, xr.DataArray(ridx*np.ones(N*2)[:,np.newaxis],
dims=['time','points'],
coords={'time':da.time.data,'points':range(np.prod(M))}
).chunk({'time':1}).data,
weights=data, chunks=(N*2,nbins), dtype=da.dtype
).compute()
我认为这是可行的，因为x中的weights和numpy.bincount都具有相同的形状，但是出现以下错误：
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
<ipython-input-7-afd3fe2d4880> in <module>()
10 coords={'time':da.time.data,'points':range(np.prod(M))}
11 ).chunk({'time':1}).data,
---> 12 weights=data, chunks=(N*2,nbins), dtype=da.dtype
13 ).compute()
14 azisum
/Users/uchidatakaya/anaconda/envs/xrft/lib/python3.6/site-packages/dask/base.py in compute(self, **kwargs)
154 dask.base.compute
155 """
--> 156 (result,) = compute(self, traverse=False, **kwargs)
157 return result
158
/Users/uchidatakaya/anaconda/envs/xrft/lib/python3.6/site-packages/dask/base.py in compute(*args, **kwargs)
393 keys = [x.__dask_keys__() for x in collections]
394 postcomputes = [x.__dask_postcompute__() for x in collections]
--> 395 results = schedule(dsk, keys, **kwargs)
396 return repack([f(r, *a) for r, (f, a) in zip(results, postcomputes)])
397
/Users/uchidatakaya/anaconda/envs/xrft/lib/python3.6/site-packages/dask/threaded.py in get(dsk, result, cache, num_workers, **kwargs)
73 results = get_async(pool.apply_async, len(pool._pool), dsk, result,
74 cache=cache, get_id=_thread_get_id,
---> 75 pack_exception=pack_exception, **kwargs)
76
77 # Cleanup pools associated to dead threads
/Users/uchidatakaya/anaconda/envs/xrft/lib/python3.6/site-packages/dask/local.py in get_async(apply_async, num_workers, dsk, result, cache, get_id, rerun_exceptions_locally, pack_exception, raise_exception, callbacks, dumps, loads, **kwargs)
499 _execute_task(task, data) # Re-execute locally
500 else:
--> 501 raise_exception(exc, tb)
502 res, worker_id = loads(res_info)
503 state['cache'][key] = res
/Users/uchidatakaya/anaconda/envs/xrft/lib/python3.6/site-packages/dask/compatibility.py in reraise(exc, tb)
110 if exc.__traceback__ is not tb:
111 raise exc.with_traceback(tb)
--> 112 raise exc
113
114 else:
/Users/uchidatakaya/anaconda/envs/xrft/lib/python3.6/site-packages/dask/local.py in execute_task(key, task_info, dumps, loads, get_id, pack_exception)
270 try:
271 task, data = loads(task_info)
--> 272 result = _execute_task(task, data)
273 id = get_id()
274 result = dumps((result, id))
/Users/uchidatakaya/anaconda/envs/xrft/lib/python3.6/site-packages/dask/local.py in _execute_task(arg, cache, dsk)
251 func, args = arg[0], arg[1:]
252 args2 = [_execute_task(a, cache) for a in args]
--> 253 return func(*args2)
254 elif not ishashable(arg):
255 return arg
/Users/uchidatakaya/anaconda/envs/xrft/lib/python3.6/site-packages/dask/compatibility.py in apply(func, args, kwargs)
91 def apply(func, args, kwargs=None):
92 if kwargs:
---> 93 return func(*args, **kwargs)
94 else:
95 return func(*args)
ValueError: object too deep for desired array
有人可以告诉我为什么我得到对象太深的错误吗？预先感谢您的帮助！