Maple Tutor
Part 4: What Maple
remembers
- Start a new line and
type
x:=15
(Make sure you are in math input mode.) Press RETURN to evaluate the line. Now
type
7.3/2.5
and press RETURN to evaluate the line.
- Go back and
delete the line
x:=15
and press RETURN. Go to a new line at the bottom of the document and enter
x
Notice that Maple still remembers that x has been assigned
the value 15 -- even though that line no longer appears in the worksheet.
We have come an
important fact about Maple. Maple remembers what has been entered
in the order it was entered.
- It doesn't matter what is currently
in the document, nor the order things appear in that document. You may have
assigned a value, erased the assigning command line, and forgotten about it.
But Maple remembers. If you use x later, assuming it is an unassigned
variable, strange things will happen.
- If variables are assigned
new values, formulas using those variables acquire new values as well.
Another important fact about
Maple: If you save a Maple file without removing the output, then
reload it later, it will look the same as when you saved it. But Maple
will not remember any of the displayed commands. All of those commands must
be reentered before you are again in the same state as when you saved and closed
the file.