What is the population field for Kernel Density?

[__17]

And when do you use none as the input in the dialog window?

[DanPatterson_Retired · Accepted solution]

How Kernel Density Works ... gives a few examples.  What data are your working with? and What software would be useful to provide more examples

[XanderBakker]

From the link that Dan shared:

The population field could be used to weight some features more heavily than others, depending on their meaning, or to allow one point to represent several observations. For example, one address might represent a condominium with six units, or some crimes might be weighted more heavily than others in determining overall crime levels. For line features, a divided highway probably has more impact than a narrow dirt road, and a high-tension line has more impact than a standard electric pole.

Also the help for the tool itself Kernel Density—Help | ArcGIS Desktop has a extended explanation of what you can specify (numeric field, shape if it contains Z values or None if each point should be counted as 1).

[rrjs67]

Hi Dr.Patterson,

I am trying to do kernel density on a shape file . But when i try to use KDE, certain fields are not visible in the population field drop down.

Why is this so? I need the missing fields for my analysis

Wondering if you had something for me?

Thank you!

[NeilAyres]

Are those missing fields numeric?

[rrjs67]

Yes Mr.Ayres,

The fields are numeric. I have also tried to create new field and copies these values ( using field calculator).But still the fields wouldn't show.

Thank you everyone.

[DanPatterson_Retired]

From the link I posted... you need point or line features... you have a polygon layer selected

It can be calculated for both point and line features.

[XanderBakker]

Hi Dan, it seems to be a point shapefile (see the top of the toc). I guess they are the centroids of the polygons.

[DanPatterson_Retired]

Ahhh, I was looking in the table of contents for the map

[rrjs67]

Yes .It is the centroid for the polygons.

I am sorry about the table of contents, i highlighted the wrong layer. 

But yes, i was working KDE on centroid of polygons.

Thank you everyone