[R-sig-Geo] Iterating and finding points in a spatial polygon

[Jim Burke]

Thanks in advance. All insight is appreciated. R is great!

HELP NEEDED DESCRIPTION
==============================
A. Matching the "lappt" to the spatial polygon. To correctly retrieve 
the "labpt" to use
    in method ptp().

    Working from the example found below. There might be a better way.
    
http://nceas.ucsb.edu/scicomp/GISSeminar/UseCases/PointInPolygonAnalysis/point_in_poly.html

B. Iteration through the two spatial polygons.

POLYGON DESCRIPTION, ITERATION, OUTPUT
==============================

1. blk_sp contains many spatial polygons that fit entirely
    into different pct_big_sp spatial polygons. No
    overlapping exists.

    Yes these are US census blocks

2. pct_big_sp contains around thirty different blk_sp
    spatial polygons.

    Yes these are precincts that contain the census blocks.

3. How this might work.

    a. iterate through every pct_big_sp, then blk_sp

    b. compares the blk_sp "labpt" (lat long format) to the
       outside edge of the larger polygon b_big_sp. Probably
       with pip().

    c. output the matching blk_sp IDs into an match_df data
       frame. On a match, gather the following items as we
       iterate.
       . blk_sp's ID     name BLK
       . pct_big_sp's ID name PCT

    d. c_df output data frame example.
       BLK               PCT
       "480019510006079",1811
       "480019510006080",1811
       "480019510006998",1811
       "480019510006999",1811
       "480039501003000",1120
       "480039501003001",1120
       "480039501003002",1120
       "480039501003003",1120

Thanks,
Jim Burke