Status buttons
==============

   This kind of button modifies the status of the calculator. The
status is showed as a set of abbreviations in the lower left part of
the display; this is called the "status area". Note that the global
state when you start `ARcalc' depends on the configuration file
`ARcalc.config'; if this file is not found, default values are assumed.

   The status buttons are the following:

`Bse'
     (numeric BaSE): allows you to choose the base in which you are
     going to work, between binary, octal, decimal or hexadecimal. The
     actual setting is shown in the status area, by one of the
     following abbreviations:

    `dec'
          decimal base

    `hex'
          hexadecimal base

    `oct'
          octal base

    `bin'
          binary base

     Pressing the `Bse' repeatedly cycles through the bases, in the
     following order:

     `... -> dec -> hex -> bin -> oct -> ...'

     When you change base, the actual expression is automatically
     cleared. This is because every number in the expression would
     change it's value in the new base. When the base is not
     hexadecimal, certain buttons become redundant (e.g. the `A', `B',
     `C', `D', `E', `F' keys, if you are working with decimal base).

     Also note that `ARcalc' is able to use real numbers only in
     decimal base; if you work in a different base you must use only
     integer numbers. This implies that many functions, although still
     available, are meaningless (e.g. the `sin(X)' function still
     works, but X must be integer, and it returns only 0 or 1). If the
     `ARcalc.config' file is not present when starting, the decimal
     base is used by default.

`Fse'
     (Fixed,Scientific,normal): this button allows you to choose the
     notation in which the results are shown. Pressing `Fse' repeatedly
     cycles through the following options:

     `Fixed': indicated by the `fix' abbreviation; the results are
     shown as numbers with a fixed number of decimal digits. You can
     fix the number of decimal digits using the `Fix' button.

     `Scientific': indicated by the `sci' abbreviation; the results are
     shown in the scientific form. Note that the number of digits fixed
     with the `Fix' button is not longer related to the number of
     decimal digits, instead it indicates the number of significant
     digits.

     `normal': indicated by the `nor' abbreviation; the results are
     shown using whichever of the above notations generates the
     shortest string.

     Note that by changing format, the result shown in the result area
     changes its format also. If the `ARcalc.config' file is not
     present when starting, the normal format is used by default.

`Drg'
     (Degrees, Radiant, Decimal Degrees (Grad)): this button allows you
     to choose the measuring system unit for arcs in trigonometrical
     functions. Pressing `Drg' repeatedly cycles through the following
     options:

        * `Degrees': indicated by the `deg' abbreviation.

        * `Radians': indicated by the `rad' abbreviation.

        * `Decimal Degrees': indicated by the `grad' abbreviation.

     If the `ARcalc.config' file is not present when starting, radians
     are used by default.

`Fix'
     (fix significant digits): this button allows you to fix the number
     of significant digits or decimal digits, depending on the chosen
     format. When you press this button in the result area you will see
     the following display:

     `Set number of digits (0 - 9)'

     Now you should press one of the digit buttons of `ARcalc', from 0
     to 9, fixing in this way the number of digits; if you press a
     different button, nothing happen, the operation is aborted keeping
     the same number of digits as before. Note that it does not matter
     how many digits you fix: every calculation is performed in an
     internal double precision format. If the `ARcalc.config' file is
     not present when starting, the number of digits is fixed to 9 by
     default.

`Inv'
     (Inverse function): this button allows you to obtain the inverse
     functions. When you press it, the `inv' abbreviation is displayed
     in the status area: if the next button you press indicates a
     function, and if is possible to invert this function, then you
     will get it; otherwise the `Inv' press produces no effects.

`Hyp'
     (Hyperbolic function): this button allows you to obtain the
     hyperbolic functions. When you press it, in the status area you
     can see the `Hyp' abbreviation: if the next button you press
     indicates a trigonometrical function, then you will get its
     corresponding hyperbolic function; otherwise the `Hyp' pression
     produces no effects.