40

Community Analysis Package

Select the adjustment to be made and click on 

Submit

 to make the change.

The possible options are as follows.

Deselect Rows: 

Removes row not wanted in this analysis. This does not delete

the data, it only removes it from the working dataset

Deselect Columns:

Removes column not wanted in this analysis. This does not

delete the data, it only removes it from the working dataset

Delete zero columns

   Every column in the data set that only contains zeros is

removed.

Delete zero rows

   Every row in the data set that only contains zeros is removed.

Remove sparse columns

   Every column in the data set which contains < x non

zero elements is removed. The value of x is entered by the user in the At least x

non zero value text box.

Remove sparse rows

   Every row in the data set which contains < x non zero

elements is removed. The value of x is entered by the user in the At least x non

zero value text box.

Beals 

Beals smoothing is used on sparse data sets where many of the samples

hold a small proportion of the total species list. As the transformation only uses

the presence/absence of species, it should not be applied to good quality

quantitative data as you will be discarding much of your information. It should only

be performed on data arranged with the samples as columns. Described and

discussed by Beals (1984) and McCune (1994) respectively, each element, eij, in

the data array is replaced by:

where i is the column (sample) number, j is the row (species) number, 

Ni

 is the

number of species in column (sample) i, 

Bothij

 is the number of samples holding

both species j and k, 

Samplesk

 is the number of samples holding species k and

maxS

 is the total number of columns (samples).

8.2

Working data screen

This screen allows you to make a variety of changes to the raw data prior to

undertaking an analysis. Initially, you will be presented with a grid filled with the

raw data; this can be adjusted using the options in the panel below the data grid.

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