Creating a data file using a spread sheet
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A data set is stored as a comma-delimited text file with the extension .csv. It has the following form:
We recommend that you organise large data sets using a spreadsheet program like Excel as this will give access to a wide range of sorting and editing procedures to ease your task. The normal arrangement of data is to have the samples (quadrats) as columns and the species as the rows. However, Excel has a maximum number of columns of 255, which can prove difficult if you have a data set with a very large number of sites/samples. If this is the case, it may be necessary to split the data set in to two or more subsets.
The table and image above show you how the data will look in Excel. The samples are arranged in columns. Each sample has a title field. Start the first sample in column 2. The data consists of the number of individuals observed in the sample. Put in zeros rather than leaving cells blank. The species names are entered from row 2 in column 1.
NOTE: Commas are not allowed in the species name. For instance, Upright Hedge-parsley should not be entered as Hedge-parsley, Upright.
When using Excel use the Save As function to save your data as a *.csv file. Ensure that the work sheet you are saving only holds the tabulated data for analysis. If your data set has been created using the convention that a blank cell means zero then use the find and replace function available in all common spreadsheets to search for blanks and replace them with 0 (zero).
Occasionally, errors occur because a blank space has been accidentally entered into a cell outside the data matrix. To prevent this happening, it is good practice, before saving your data set as a .csv file, to highlight the first 10 or so blank rows and columns below and to the right of the data matrix, and press 'Delete'. This will clear the cells of any accidentally-entered contents.
The data set above looks like this if viewed in a word processor program (such as Word, Word Perfect) or text viewer such as Notepad:
Note the leading comma on the first row, which will make the first cell blank.