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1.0 Introduction
----------------
This is a short walkthrough of the polydemo program, with examples of
the use of all of the available commands. I am assuming that you have
already looked at the header of the source code of polydemo, which describes
the options available in the polydemo.
When a series of commands or entries must be given, they will be listed
here separated by commas. Each entry in such a list should be followed by
pressing Return or Enter. Single-letter commands must always be followed
with Enter as well. The case of any letter is ignored.
2.0 Preparing the polydemo program
----------------------------------
Polydemo requires the library polystuf, also included on this disk. To
set up polydemo for running, first translate polystuf into ucode files with
ICONT -c polystuf
and then translate polydemo with
ICONT polydemo
after which you can run polydemo in whatever manner your system allows.
3.0 A sample run
----------------
Let's say we had to perform the following: find the result of evaluating
4 3.1 0.7 5 4
(9x + 6x + 5 - 3x ) - (12x - 4.2x + x) at x = 2.2.
Start the polydemo program. A menu of options will be displayed, as
will the slots that are filled (none yet) and a prompt containing valid
characters corresponding to the options. Enter R to read in a polynomial from
the keyboard, then give A as the slot of the first polynomial. Enter these
numbers: 9, 4, 6, 3.1, 5, 0, -3, 0.7, 0. Now, the first polynomial will be
stored in slot "a." Note that the 0 is necessary after the 5 to use a
constant term, and that the 0 at the end is for stopping data entry.
A similar process can be used for the second polynomial. Inputting
R, B, 12, 5, -4.2, 4, 1, 1, 0 will place that polynomial in slot "b."
Now, check to make sure you've entered the polynomials correctly. Type
W for "write" and A for slot "a," to display the first polynomial on the
screen. It should appear as 9x^4 + 6x^3.1 + -3x^0.7 + 5. Do the same for
the second polynomial (replacing the A with a B). The output should be
12x^5 + -4.2x^4 + x.
To find their difference, enter S for subtract, then A, B to indicate
those two polynomials, then C as a slot for the answer. Note that the result
isn't immediately displayed; you must use W, C for that. The answer should
be -12x^5 + 13.2x^4 + 6x^3.1 + -x + -3x^0.7 + 5.
Finally, to evaluate this polynomial at x = 2.2, type E for evaluate,
C for the slot in which that polynomial is held, then 2.2 for the x-value.
You should receive the message "The result is -242.498468213815," or something
similar, depending on the precision of real numbers in your implementation of
Icon.
The Add and Multiply commands are invoked similarly to the Subtract
command. The Clear option allows you to empty a slot, making room for a new
polynomial. This is necessary because you cannot overwrite an existing
polynomial. Asking for Help displays the list of options and the letters
needed to access them. Lastly, using Quit exits the program.
It would be good to test operations in which one or both polynomials
are zero. A zero polynomial is made when, during entry, a 0 is the first and
only coefficient given, or when it is the result of an operation. Also, to
make sure no "1x", "-1x" or "x^1" appears in a written polynomial (these
should be "x", "-x", and "x," respectively), try working with polynomials that
have these terms.
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