html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,performed_via_github_app,issue
https://github.com/pydata/xarray/issues/742#issuecomment-226486770,https://api.github.com/repos/pydata/xarray/issues/742,226486770,MDEyOklzc3VlQ29tbWVudDIyNjQ4Njc3MA==,4304478,2016-06-16T13:36:28Z,2016-06-16T13:37:44Z,NONE,"Something akin to the pandas dataframe `update` would have value - then you could create an empty array structure and populate it as necessary:

``` python
import pandas as pd
df = pd.DataFrame(index=range(5), columns=['a','b','c','d'])
df2 = pd.DataFrame(index=range(3), columns=['a'], data=range(3))
df.update(df2)
```

```
     a    b    c    d
0    0  NaN  NaN  NaN
1    1  NaN  NaN  NaN
2    2  NaN  NaN  NaN
3  NaN  NaN  NaN  NaN
4  NaN  NaN  NaN  NaN
```

But, not sure if empty array construction is supported?
","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,130753818
https://github.com/pydata/xarray/issues/742#issuecomment-226003087,https://api.github.com/repos/pydata/xarray/issues/742,226003087,MDEyOklzc3VlQ29tbWVudDIyNjAwMzA4Nw==,4304478,2016-06-14T20:18:11Z,2016-06-14T20:18:11Z,NONE,"I'm having a similar issue, expanding the complexity in that I want to concatenate across multiple dimensions. I'm not sure if that's a cogent way to explain it, but here's an example. I have:

``` python
m = xr.DataArray(data=[[[1.1, 1.2, 1.3]]], 
                 coords={'Dim1': ['A', 'B', 'C'], 'Dim2':['D'], 'Dim3':['F']})
n = xr.DataArray(data=[[[2.1, 2.2, 2.3]]], 
                 coords={'Dim1': ['A', 'B', 'C'], 'Dim2':['E'], 'Dim3':['F']})
o = xr.DataArray(data=[[[3.1, 3.2, 3.3]]], 
                 coords={'Dim1': ['A', 'B', 'C'], 'Dim2':['D'], 'Dim3':['G']})
p = xr.DataArray(data=[[[4.1, 4.2, 4.3]]], 
                 coords={'Dim1': ['A', 'B', 'C'], 'Dim2':['E'], 'Dim3':['G']})
```

Which I want to merge into a single, fully populated array similar to what I'd get if I did:

``` python
data =[[[ 1.1,  1.2,  1.3],
        [ 3.1,  3.2,  3.3]],

       [[ 2.1,  2.2,  2.3],
        [ 4.1,  4.2,  4.3]]]

xr.DataArray(data=data, 
             coords={'Dim1': ['A', 'B', 'C'], 'Dim2':['D', 'E'], 'Dim3':['F', 'G']})
```

i.e.

``` python
<xarray.DataArray (Dim2: 2, Dim3: 2, Dim1: 3)>
array([[[ 1.1,  1.2,  1.3],
        [ 3.1,  3.2,  3.3]],

       [[ 2.1,  2.2,  2.3],
        [ 4.1,  4.2,  4.3]]])
Coordinates:
  * Dim2     (Dim2) |S1 'D' 'E'
  * Dim3     (Dim3) |S1 'F' 'G'
  * Dim1     (Dim1) |S1 'A' 'B' 'C'
```

@jcmgray's function is pretty close, although the array indicies are described slightly differently (I'm not sure if this is a big deal or not...). Note the 'object' type for Dim2 and Dim3:

``` python
<xarray.DataArray (Dim2: 2, Dim3: 2, Dim1: 3)>
array([[[ 1.1,  1.2,  1.3],
        [ 3.1,  3.2,  3.3]],

       [[ 2.1,  2.2,  2.3],
        [ 4.1,  4.2,  4.3]]])
Coordinates:
  * Dim2     (Dim2) object 'D' 'E'
  * Dim3     (Dim3) object 'F' 'G'
  * Dim1     (Dim1) |S1 'A' 'B' 'C'
```

It would be great to have a canonical way to do this. What should I try?
","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,130753818