Analyse des données spatio-temporelles

Question

<\/HEAD>Existe-t-il un moyen de réaliser une analyse des points chauds émergents qui illustre le changement des valeurs associées aux points ou aux polygones au fil du temps, plutôt que de simplement compter le nombre de points qui se produisent au fil du temps ?<\/P><\/BODY><\/HTML>

FloraVale · Answer

Hi Jennifer Weaver,

With the Create Space Time Cube By Aggregating Points tool you can add summary fields so that values associated with your points are summarized.

Available statistic types are:

* SUM-Adds the total value for the specified field within each bin.
* MEAN-Calculates the average for the specified field within each bin.
* MIN-Finds the smallest value for all records of the specified field within each bin.
* MAX-Finds the largest value for all records of the specified field within each bin.
* STD-Finds the standard deviation on values in the specified field within each bin.
* MEDIAN-Finds the sorted middle value of all records of the specified field within each bin.

With the Create Space Time Cube From Defined Locations tool you can provide point or polygon data with values at the same location over time and analyze them without spatial aggregation.

Hope this helps,

Flora

AndrewHargreaves2 · Answer

I think I might have the same question. We have data of fire hydrant assessments by several crews over several weeks. They record several different factors about each hydrant such as: Pressure, or length of time it was flowed for. It’s relatively easy to find trends in each of these dimensions like:

* Paul is more productive than Bobby.
* We are more productive in the morning vs afternoon. 
* We’re more productive in a quiet residential neighborhoods where hydrants are uniformly spaced at 500ft.
* The shorter the flow time, or the lower the pressure, the more productive we are.

But I want some kind of multivariate analysis and the problem with Emerging HotSpots is that they will only assess a single analysis variable at a time (eg: Assessment Count, or ave FLOWTIME, or Std Dev of PRESSURE) and tell me if, over time in that area, that variable goes hot (increases) or cold (decreases), oscillates or is sporadic. What I want is to know if COUNT lowered over time in this AREA as Std Dev of PRESSURE increased. Thoughts?

Analysis‌ ArcGIS Analyse‌ Managing Data‌

AdrianWelsh · Answer

Jen,

I am thinking not natively. I wonder if you would need to have an extra attribute that records this change in time and then do the emerging hot spot analysis.