How to distribute bank deposits, folowing the population of the area

[RobertoLopez]

I am trying to "spread" the money deposited in a bank branch among the surrounding area. If I use the "density" funtion of Spatial Analyst, the deposits are spread circularly. But I want to spread them following the population in the area (the higher population, the higher the deposits).

Is there a way to do this?

(I am thinking in creating a proximity raster, with a cost distance defined as the inverse of population density. But it looks like a too convoluted way).

[RamB]

Use of "spatial weights matrix" will be of great help to you. see here

regards,

[RobertoLopez]

I have been trying to figure out how to achieve what I want with the help of your succinct advice. But I couldn't. The steps that I followed were:

1. First I researched what the "spatial weights matrix" was.

2. Then, I investigated which tools use it, and which of these tools can be used for my problem (distribute the amount of deposits among the population surrounding a branch).

The only tools that, I believe, can be used for my problem AND uses the "spatial weights matrix" was "Hot Spot Analysis (Getis-Ord Gi*)" (please, correct me if I am wrong). This tool can perform a hot spot analysis, that uses an spatial weight matrix.

3. Then, comes the task of creating the appropriate spatial weight matrix. As I want the distribution of bank deposits to follow the distribution of population, I thought that the most appropriate spatial conceptualization was to create a "cost distance" where the "cost" was the inverse of the population. This way, the deposits will spread farther in polygons more populated.

To built this "spatial weights matrix", I followed this steps:

     a. Convert the Census block polygons to a raster, using "population" as the value.
     b. Calculate the inverse of population for each cells, using the raster calculator. This was my "cost raster"
     c. Calculate a "cost distance" using the previous raster.
Here is the result:
[ATTACH=CONFIG]19811[/ATTACH]
     d. Here a get lost, as I don't know how to create the "input table" required by the "Generate Spatial Weight Matrix" tool.

Beside, this procedure is so convoluted that I have the feeling of being looking in the wrong direction.

Can you give me some advice?

[RobertoLopez]

Do you think that, in order to distribute a point feature among the surrounding population, I should look into "Heat Maps" tools  or more into "Interpolation" tools.

RL

[RamB]

May be a simple gravity formula can work ? to keep it simple !

money deposited = population in an area* accounts in bank / (distance between bank and that population area)

the result would mean, that closer and higher the population, more will be the deposits from that population.

regards,

[RamB]

Just edited the power function for deterrence, it is the basic gravity formula from physics book.

May be a simple gravity formula can work ? to keep it simple !

money deposited = population in an area* accounts in bank / (distance between bank and that population area)^2

the result would mean, that closer and higher the population, more will be the deposits from that population.

regards,