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User-defined Constants
A constant is like a variable in that it can be used instead of a number. However, you cannot change the value of a constant simply by assigning it a different value.
You create a constant by first defining a variable of the same name. For
example, to define the constant c as the velocity of light
in a vacuum, evaluate the expression:
c = 299792458 (This is the exact value, by definition, in
metres per second, as of 1998.)
Then select the menu item View / Variables. This will show the
Variables window which lists all variables, constants and user-defined
functions, and allows you to convert variables to constants, and vice
versa. Scroll the display if necessary until you see the variable c
and do a right-click on it. A menu pops up to allow you to change this variable
to a constant. If you do this, close the window, and try to give c
a value (even the same value), UltimaCalc will object. If you do need to
change the value of a constant, change it to a variable first.
For a handy listing of more than a hundred values of physical and
conversion constants, and some others too, see the constants
reference window.
The constant pi is special in that it cannot be turned into a variable. The
variable last is also special, in that it cannot be made a constant.
Neither pi nor last can be deleted.
You can change the value of a constant (other than pi) by converting it to
a variable, changing its value, and then making it a constant again.