Answers for I Chi Spreadsheet Problems of Chapters 4 and 7
This folder contains example I Chi models that have been constructed as answers
to problems posed at the back of Chapters 4 and 7. Here are some general comments on
those models.
Foremost, the models are example answers. Your answers will probably differ in
organization of the models and possibly in the processes considered. To understand these
example answers, you may have to spend some time reviewing the question asked and
looking at the detailed row and column structure of the model in the example answer. In
short, now that you worked on your model, you also have even more work to understand
Mr. Polychaete’s models.
The spreadsheet models are organized generally using the principles and
procedures of Sections 4.3 and 4.4. Also, here are four guidelines below that can help you
navigate these example models.
1. Graphs update when you type in new values for the master variables. These
master variables are given in bold in the upper left corner of the worksheets.
2. To see the more detailed structure of the model, you will probably have to
move the graphs. Each row includes gains and losses for important processes, with one
row representing an incremental step in time (usually) or space (in some cases). But now
view the columns and identify the processes that are included as the columns within each
row. Write down what these processes are, and see if you have the same processes in
your model. (Recall that the order of the processes does not make a difference, so that if
you have included the same processes within your rows, but in a different order, that will
produce the same overall dynamics).
3. As necessary, move to the most detailed level of actually following the math
calculations given in the individual cells. To see the equations, use your cursor to
highlight an individual cell, and the equation for that cell will appear in the toolbar just
above the column headings, to the right of “f(x) =”. Move your cursor to the tool bar
equation and click there. This will highlight in color the values used in the equation, so
that you can easily see which values were used in the spreadsheet. Generally, equations
are the I Chi equations for gain and loss given in Chapter 4.3. Other equations used in the
book are summarized in the printed Appendix.
4. Most of the important information is in the first row. Find the first row and
column that gives initial conditions, then use your cursor to move across the row from
cell to cell, to the right, viewing equations in the toolbar as you go. This will give you the
detailed calculations used in the model, for comparison with your work.