Using FeatureClassToNumPyArray for a Point Feature Class

RobW

I am trying to get acquainted with numpy and point feature classes in ArcGIS and I started with what I thought was an simple example. 

I am reading in a single part point feature class (contains fields named: X,  Y and YR) via FeatureClassToNumPyArray. I am interested in finding the 'max' value within a given field using numpy. 

A snippet of my code is below: 

array <SPAN class="operator token">=</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>da<SPAN class="punctuation token">.</SPAN>FeatureClassToNumPyArray<SPAN class="punctuation token">(</SPAN>inputFC<SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">"X"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"Y"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"YR"</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN>
<SPAN class="keyword token">print</SPAN> array<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

It prints: 

[(2531050.0, 7431830.0, 2018.0) (2531050.0, 7431810.0, 2018.0)
 (2531050.0, 7431850.0, 2018.0) (2531050.0, 7431930.0, 2018.0)
 (2531050.0, 7431890.0, 2018.0) (2531050.0, 7431870.0, 2018.0)
 (2531050.0, 7431910.0, 2018.0) (2531050.0, 7431950.0, 2018.0)
 (2531050.0, 7431970.0, 2018.0) (2531050.0, 7432030.0, 2018.0)
 (2531070.0, 7428230.0, 2018.0)]<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

A slight change in the code attempts to get the max for each column by specifying axis = 0: 

array <SPAN class="operator token">=</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>da<SPAN class="punctuation token">.</SPAN>FeatureClassToNumPyArray<SPAN class="punctuation token">(</SPAN>inputFC<SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">"X"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"Y"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"YR"</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN>
 <SPAN class="keyword token">print</SPAN> numpy<SPAN class="punctuation token">.</SPAN>amax<SPAN class="punctuation token">(</SPAN>array<SPAN class="punctuation token">,</SPAN> axis <SPAN class="operator token">=</SPAN> <SPAN class="number token">0</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

However the script output is: 

File "work5_EFI_sum.py", line 102, in <module>
 doSummary()
 File "work5_EFI_sum.py", line 20, in doSummary
 print numpy.amax(array, axis = 0)
 File "C:\Python27\ArcGIS10.6\lib\site-packages\numpy\core\fromnumeric.py", line 2140, in amax
 out=out, keepdims=keepdims)
 File "C:\Python27\ArcGIS10.6\lib\site-packages\numpy\core\_methods.py", line 26, in _amax
 return umr_maximum(a, axis, None, out, keepdims)
TypeError: cannot perform reduce with flexible type<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

Any idea on what's going on?

DanPatterson_Retired

Your dtype has the year as a float, was that by design?

Use numpy 1.16.4

xy
Out<SPAN class="punctuation token">[</SPAN><SPAN class="number token">6</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">:</SPAN> 
array<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="number token">300004.72</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000004.73</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="number token">300017.5</SPAN> <SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000007</SPAN><SPAN class="punctuation token">.</SPAN>  <SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN>
       <SPAN class="punctuation token">(</SPAN><SPAN class="number token">300013</SPAN><SPAN class="punctuation token">.</SPAN>  <SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000012.67</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="number token">300015</SPAN><SPAN class="punctuation token">.</SPAN>  <SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000030</SPAN><SPAN class="punctuation token">.</SPAN>  <SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN>
       <SPAN class="punctuation token">(</SPAN><SPAN class="number token">300002.4</SPAN> <SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000027.4</SPAN> <SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="number token">300022</SPAN><SPAN class="punctuation token">.</SPAN>  <SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000027</SPAN><SPAN class="punctuation token">.</SPAN>  <SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN>
       <SPAN class="punctuation token">(</SPAN><SPAN class="number token">300014</SPAN><SPAN class="punctuation token">.</SPAN>  <SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000024</SPAN><SPAN class="punctuation token">.</SPAN>  <SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="number token">300020.96</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000020.96</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN>
       <SPAN class="punctuation token">(</SPAN><SPAN class="number token">300024.4</SPAN> <SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000018.93</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="number token">300031.32</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000017.85</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN>
       <SPAN class="punctuation token">(</SPAN><SPAN class="number token">300029.88</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000011.35</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="number token">300033.06</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000025.98</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
      dtype<SPAN class="operator token">=</SPAN><SPAN class="punctuation token">{</SPAN><SPAN class="string token">'names'</SPAN><SPAN class="punctuation token">:</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="string token">'X_cent'</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="string token">'Y_cent'</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'formats'</SPAN><SPAN class="punctuation token">:</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="string token">'<f8'</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="string token">'<f8'</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'offsets'</SPAN><SPAN class="punctuation token">:</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="number token">4</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="number token">12</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'itemsize'</SPAN><SPAN class="punctuation token">:</SPAN><SPAN class="number token">76</SPAN><SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN>

<SPAN class="keyword token">from</SPAN> numpy<SPAN class="punctuation token">.</SPAN>lib<SPAN class="punctuation token">.</SPAN>recfunctions <SPAN class="keyword token">import</SPAN> structured_to_unstructured <SPAN class="keyword token">as</SPAN> stu

stu<SPAN class="punctuation token">(</SPAN>xy<SPAN class="punctuation token">)</SPAN>
Out<SPAN class="punctuation token">[</SPAN><SPAN class="number token">8</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">:</SPAN> 
array<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">[</SPAN> <SPAN class="number token">300004.72</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000004.73</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
       <SPAN class="punctuation token">[</SPAN> <SPAN class="number token">300017.5</SPAN> <SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000007</SPAN><SPAN class="punctuation token">.</SPAN>  <SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
       <SPAN class="punctuation token">[</SPAN> <SPAN class="number token">300013</SPAN><SPAN class="punctuation token">.</SPAN>  <SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000012.67</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
       <SPAN class="punctuation token">[</SPAN> <SPAN class="number token">300015</SPAN><SPAN class="punctuation token">.</SPAN>  <SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000030</SPAN><SPAN class="punctuation token">.</SPAN>  <SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
       <SPAN class="punctuation token">[</SPAN> <SPAN class="number token">300002.4</SPAN> <SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000027.4</SPAN> <SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
       <SPAN class="punctuation token">[</SPAN> <SPAN class="number token">300022</SPAN><SPAN class="punctuation token">.</SPAN>  <SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000027</SPAN><SPAN class="punctuation token">.</SPAN>  <SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
       <SPAN class="punctuation token">[</SPAN> <SPAN class="number token">300014</SPAN><SPAN class="punctuation token">.</SPAN>  <SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000024</SPAN><SPAN class="punctuation token">.</SPAN>  <SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
       <SPAN class="punctuation token">[</SPAN> <SPAN class="number token">300020.96</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000020.96</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
       <SPAN class="punctuation token">[</SPAN> <SPAN class="number token">300024.4</SPAN> <SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000018.93</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
       <SPAN class="punctuation token">[</SPAN> <SPAN class="number token">300031.32</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000017.85</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
       <SPAN class="punctuation token">[</SPAN> <SPAN class="number token">300029.88</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000011.35</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
       <SPAN class="punctuation token">[</SPAN> <SPAN class="number token">300033.06</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000025.98</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN>

np<SPAN class="punctuation token">.</SPAN>max<SPAN class="punctuation token">(</SPAN>stu<SPAN class="punctuation token">(</SPAN>xy<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> axis<SPAN class="operator token">=</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">)</SPAN>
Out<SPAN class="punctuation token">[</SPAN><SPAN class="number token">9</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">:</SPAN> array<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN> <SPAN class="number token">300033.06</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">5000030</SPAN><SPAN class="punctuation token">.</SPAN>  <SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

Or make it easier on yourself if you don't have a more recent version of numpy installed

np<SPAN class="punctuation token">.</SPAN>max<SPAN class="punctuation token">(</SPAN>xy<SPAN class="punctuation token">[</SPAN><SPAN class="string token">'X_cent'</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN>
Out<SPAN class="punctuation token">[</SPAN><SPAN class="number token">17</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="number token">300033.05638901744</SPAN>


np<SPAN class="punctuation token">.</SPAN>max<SPAN class="punctuation token">(</SPAN>xy<SPAN class="punctuation token">[</SPAN><SPAN class="string token">'Y_cent'</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN>
Out<SPAN class="punctuation token">[</SPAN><SPAN class="number token">19</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="number token">5000030.0</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>