Quadrat Counts and Goodness-of-fit

Three point patterns (Japanese black pines, redwood seedlings, and biological cells) have each been reduced to quadrat counts through rectangular grids of size 2x2, 3x3, and 4x4. The figures and listings that follow show the original point patterns, the count listings for each grid size, and then a plot showing the counts within their respective quadrats.

To each data set (point pattern and grid size):

  1. Fit binomial, Poisson, and negative binomial distributions.
  2. Test for goodness-of-fit to the Poisson model using the Pearson chi-square statistic, and use the Pearson chi-square and Deviance statistics to help judge fit of the other models.
  3. Specify which distribution you think best describes the quadrat counts.
  4. To summarize over grid sizes, state whether the distribution selected appears consistent over the grid sizes or whether the distribution selected depends upon the grid size.


 

 


 
Japanese Black Pines
2 x 2 Grid

Quadrat X Y COUNT
1 0.25 0.25 13
2 0.75 0.25 13
3 0.25 0.75 22
4 0.75 0.75 17

 


 
Japanese Black Pines
2 x 2 Grid

                    Plot of Y*X$COUNT.  Symbol used is ' '.                     
                                                                                
    --+-------------+-------------+-------------+-------------+-------------+---
  Y |                                    |                                     |
1.0 +                                    |                                     +
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
0.8 +                                    |                                     +
    |                                    |                                     |
    |                   22               |                 17                  |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
0.6 +                                    |                                     +
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |------------------------------------+-------------------------------------|
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
0.4 +                                    |                                     +
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                   13               |                 13                  |
    |                                    |                                     |
0.2 +                                    |                                     +
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
0.0 +                                    |                                     +
    |                                    |                                     |
    --+-------------+-------------+-------------+-------------+-------------+---
     0.0           0.2           0.4           0.6           0.8           1.0  
                                                                                
                                         X                                      

 


 
Japanese Black Pines
3 x 3 Grid

Quadrat X Y COUNT
1 0.16667 0.16667 4
2 0.50000 0.16667 8
3 0.83333 0.16667 8
4 0.16667 0.50000 10
5 0.50000 0.50000 4
6 0.83333 0.50000 3
7 0.16667 0.83333 6
8 0.50000 0.83333 15
9 0.83333 0.83333 7

 


 
Japanese Black Pines
3 x 3 Grid

                    Plot of Y*X$COUNT.  Symbol used is ' '.                     
                                                                                
    --+-------------+-------------+-------------+-------------+-------------+---
  Y |                        |                       |                         |
1.0 +                        |                       |                         +
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |             6          |           15          |          7              |
0.8 +                        |                       |                         +
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |------------------------+-----------------------+-------------------------|
    |                        |                       |                         |
    |                        |                       |                         |
0.6 +                        |                       |                         +
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |             10         |           4           |          3              |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
0.4 +                        |                       |                         +
    |                        |                       |                         |
    |                        |                       |                         |
    |------------------------+-----------------------+-------------------------|
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
0.2 +                        |                       |                         +
    |             4          |           8           |          8              |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
0.0 +                        |                       |                         +
    |                        |                       |                         |
    --+-------------+-------------+-------------+-------------+-------------+---
     0.0           0.2           0.4           0.6           0.8           1.0  
                                                                                
                                         X                                      

 


 
Japanese Black Pines
4 x 4 Grid

Quadrat X Y COUNT
1 0.125 0.125 2
2 0.375 0.125 6
3 0.625 0.125 6
4 0.875 0.125 5
5 0.125 0.375 4
6 0.375 0.375 1
7 0.625 0.375 2
8 0.875 0.375 0
9 0.125 0.625 5
10 0.375 0.625 5
11 0.625 0.625 5
12 0.875 0.625 4
13 0.125 0.875 4
14 0.375 0.875 8
15 0.625 0.875 4
16 0.875 0.875 4

 


 
Japanese Black Pines
4 x 4 Grid

                    Plot of Y*X$COUNT.  Symbol used is ' '.                     
                                                                                
    --+-------------+-------------+-------------+-------------+-------------+---
  Y |                   |                |                 |                   |
1.0 +                   |                |                 |                   +
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |          4        |       8        |        4        |       4           |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
0.8 +                   |                |                 |                   +
    |                   |                |                 |                   |
    |-------------------+----------------+-----------------+-------------------|
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |          5        |       5        |        5        |       4           |
0.6 +                   |                |                 |                   +
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |-------------------+----------------+-----------------+-------------------|
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
0.4 +                   |                |                 |                   +
    |          4        |       1        |        2        |       0           |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |-------------------+----------------+-----------------+-------------------|
    |                   |                |                 |                   |
0.2 +                   |                |                 |                   +
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |          2        |       6        |        6        |       5           |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
0.0 +                   |                |                 |                   +
    |                   |                |                 |                   |
    --+-------------+-------------+-------------+-------------+-------------+---
     0.0           0.2           0.4           0.6           0.8           1.0  
                                                                                
                                         X                                      

 


 

 


 
Redwood Seedlings
2 x 2 Grid

Quadrat X Y COUNT
1 0.25 0.25 9
2 0.75 0.25 18
3 0.25 0.75 21
4 0.75 0.75 14

 


 
Redwood Seedlings
2 x 2 Grid

                    Plot of Y*X$COUNT.  Symbol used is ' '.                     
                                                                                
    --+-------------+-------------+-------------+-------------+-------------+---
  Y |                                    |                                     |
1.0 +                                    |                                     +
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
0.8 +                                    |                                     +
    |                                    |                                     |
    |                   21               |                 14                  |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
0.6 +                                    |                                     +
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |------------------------------------+-------------------------------------|
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
0.4 +                                    |                                     +
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                   9                |                 18                  |
    |                                    |                                     |
0.2 +                                    |                                     +
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
0.0 +                                    |                                     +
    |                                    |                                     |
    --+-------------+-------------+-------------+-------------+-------------+---
     0.0           0.2           0.4           0.6           0.8           1.0  
                                                                                
                                         X                                      

 


 
Redwood Seedlings
3 x 3 Grid

Quadrat X Y COUNT
1 0.16667 0.16667 0
2 0.50000 0.16667 6
3 0.83333 0.16667 13
4 0.16667 0.50000 13
5 0.50000 0.50000 8
6 0.83333 0.50000 2
7 0.16667 0.83333 5
8 0.50000 0.83333 9
9 0.83333 0.83333 6

 


 
Redwood Seedlings
3 x 3 Grid

                    Plot of Y*X$COUNT.  Symbol used is ' '.                     
                                                                                
    --+-------------+-------------+-------------+-------------+-------------+---
  Y |                        |                       |                         |
1.0 +                        |                       |                         +
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |             5          |           9           |          6              |
0.8 +                        |                       |                         +
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |------------------------+-----------------------+-------------------------|
    |                        |                       |                         |
    |                        |                       |                         |
0.6 +                        |                       |                         +
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |             13         |           8           |          2              |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
0.4 +                        |                       |                         +
    |                        |                       |                         |
    |                        |                       |                         |
    |------------------------+-----------------------+-------------------------|
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
0.2 +                        |                       |                         +
    |             0          |           6           |          13             |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
0.0 +                        |                       |                         +
    |                        |                       |                         |
    --+-------------+-------------+-------------+-------------+-------------+---
     0.0           0.2           0.4           0.6           0.8           1.0  
                                                                                
                                         X                                      

 


 
Redwood Seedlings
4 x 4 Grid

Quadrat X Y COUNT
1 0.125 0.125 0
2 0.375 0.125 4
3 0.625 0.125 2
4 0.875 0.125 9
5 0.125 0.375 5
6 0.375 0.375 0
7 0.625 0.375 7
8 0.875 0.375 0
9 0.125 0.625 8
10 0.375 0.625 2
11 0.625 0.625 5
12 0.875 0.625 2
13 0.125 0.875 2
14 0.375 0.875 9
15 0.625 0.875 2
16 0.875 0.875 5

 


 
Redwood Seedlings
4 x 4 Grid

                    Plot of Y*X$COUNT.  Symbol used is ' '.                     
                                                                                
    --+-------------+-------------+-------------+-------------+-------------+---
  Y |                   |                |                 |                   |
1.0 +                   |                |                 |                   +
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |          2        |       9        |        2        |       5           |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
0.8 +                   |                |                 |                   +
    |                   |                |                 |                   |
    |-------------------+----------------+-----------------+-------------------|
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |          8        |       2        |        5        |       2           |
0.6 +                   |                |                 |                   +
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |-------------------+----------------+-----------------+-------------------|
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
0.4 +                   |                |                 |                   +
    |          5        |       0        |        7        |       0           |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |-------------------+----------------+-----------------+-------------------|
    |                   |                |                 |                   |
0.2 +                   |                |                 |                   +
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |          0        |       4        |        2        |       9           |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
0.0 +                   |                |                 |                   +
    |                   |                |                 |                   |
    --+-------------+-------------+-------------+-------------+-------------+---
     0.0           0.2           0.4           0.6           0.8           1.0  
                                                                                
                                         X                                      

 


 

 


 
Biological Cells
2 x 2 Grid

Quadrat X Y COUNT
1 0.25 0.25 11
2 0.75 0.25 10
3 0.25 0.75 10
4 0.75 0.75 11

 


 
Biological Cells
2 x 2 Grid

                    Plot of Y*X$COUNT.  Symbol used is ' '.                     
                                                                                
    --+-------------+-------------+-------------+-------------+-------------+---
  Y |                                    |                                     |
1.0 +                                    |                                     +
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
0.8 +                                    |                                     +
    |                                    |                                     |
    |                   10               |                 11                  |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
0.6 +                                    |                                     +
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |------------------------------------+-------------------------------------|
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
0.4 +                                    |                                     +
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                   11               |                 10                  |
    |                                    |                                     |
0.2 +                                    |                                     +
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
    |                                    |                                     |
0.0 +                                    |                                     +
    |                                    |                                     |
    --+-------------+-------------+-------------+-------------+-------------+---
     0.0           0.2           0.4           0.6           0.8           1.0  
                                                                                
                                         X                                      

 


 
Biological Cells
3 x 3 Grid

Quadrat X Y COUNT
1 0.16667 0.16667 3
2 0.50000 0.16667 6
3 0.83333 0.16667 4
4 0.16667 0.50000 4
5 0.50000 0.50000 7
6 0.83333 0.50000 6
7 0.16667 0.83333 3
8 0.50000 0.83333 6
9 0.83333 0.83333 3

 


 
Biological Cells
3 x 3 Grid

                    Plot of Y*X$COUNT.  Symbol used is ' '.                     
                                                                                
    --+-------------+-------------+-------------+-------------+-------------+---
  Y |                        |                       |                         |
1.0 +                        |                       |                         +
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |             3          |           6           |          3              |
0.8 +                        |                       |                         +
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |------------------------+-----------------------+-------------------------|
    |                        |                       |                         |
    |                        |                       |                         |
0.6 +                        |                       |                         +
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |             4          |           7           |          6              |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
0.4 +                        |                       |                         +
    |                        |                       |                         |
    |                        |                       |                         |
    |------------------------+-----------------------+-------------------------|
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
0.2 +                        |                       |                         +
    |             3          |           6           |          4              |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
    |                        |                       |                         |
0.0 +                        |                       |                         +
    |                        |                       |                         |
    --+-------------+-------------+-------------+-------------+-------------+---
     0.0           0.2           0.4           0.6           0.8           1.0  
                                                                                
                                         X                                      

 


 
Biological Cells
4 x 4 Grid

Quadrat X Y COUNT
1 0.125 0.125 2
2 0.375 0.125 3
3 0.625 0.125 3
4 0.875 0.125 2
5 0.125 0.375 2
6 0.375 0.375 4
7 0.625 0.375 2
8 0.875 0.375 3
9 0.125 0.625 2
10 0.375 0.625 1
11 0.625 0.625 4
12 0.875 0.625 3
13 0.125 0.875 3
14 0.375 0.875 4
15 0.625 0.875 2
16 0.875 0.875 2

 


 
Biological Cells
4 x 4 Grid

                    Plot of Y*X$COUNT.  Symbol used is ' '.                     
                                                                                
    --+-------------+-------------+-------------+-------------+-------------+---
  Y |                   |                |                 |                   |
1.0 +                   |                |                 |                   +
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |          3        |       4        |        2        |       2           |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
0.8 +                   |                |                 |                   +
    |                   |                |                 |                   |
    |-------------------+----------------+-----------------+-------------------|
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |          2        |       1        |        4        |       3           |
0.6 +                   |                |                 |                   +
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |-------------------+----------------+-----------------+-------------------|
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
0.4 +                   |                |                 |                   +
    |          2        |       4        |        2        |       3           |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |-------------------+----------------+-----------------+-------------------|
    |                   |                |                 |                   |
0.2 +                   |                |                 |                   +
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |          2        |       3        |        3        |       2           |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
    |                   |                |                 |                   |
0.0 +                   |                |                 |                   +
    |                   |                |                 |                   |
    --+-------------+-------------+-------------+-------------+-------------+---
     0.0           0.2           0.4           0.6           0.8           1.0  
                                                                                
                                         X