Documentation on the following topics is available:
Since version 1.2.0 galculator features a formula entry mode. This mode is one more step towards a calculator accepting input as written on the paper. galculator's formula entry mode aims to provide all the features of the algebraic mode (and even to go beyond ...).
This part of galculator is developed actively. This section gives an overview of the functions currently implemented and points out some restrictions.
Formula entry mode accepts decimal numbers as input as well as hexadecimal, binary and octal numbers. The latter three have to be entered with a prefix:
Let's speak of factorial and complement as functions. Most functions' argument has to be enclosed by brackets. Therefore sin 3 is not allowed and has to be written as sin(3). User defined functions can be used in formula entry mode without any restrictions!
If formula entry mode's parser encounters an (syntax) error, the formula entry text is turned red.
Since version 1.3.0 galculator features a paper mode, which offers a very simple GUI along with the functionality of formula entry mode. In the entry field, enter the expression following the same rules as for formula entry mode. Hitting return or clicking the button to the right will evaluate the expression and add it as well as the result to the list view above. Double click on any row of that list view to copy the corresponding expression to the entry field.
Since version 1.2.1 galculator also features user defined functions. They can be called with the fun button next to the constant button and work like the other function buttons like sin, cos, etc. (except that inverse and hyperbolic are not supported). User functions can be defined in the Preferences dialog (Functions page). The function name can be any string beginning with a letter. So far, only a single variable is allowed. Expression gives the string expression of the function with respect to the specified variable:
User defined functions can depend on other user functions:
User functions can also be called from formula entry mode.
Left shifting is done with the LSH button.
You can change number base, angle base and the notation mode by simply clicking on the corresponding module in the display's second line. If changing from e.g. decimal number base to binary mode results in an "inf" value on the display, the initial value was too big. Due to the limited display length every mode has its own limits:
If computing in hexadecimal, octal or binary mode, inf means that an overflow has happened.
If in hexadecimal, octal or binary signed mode, a negative number won't be represented with a leading minus but as 2's complement with respect to the chosen variable length.
It is not possible to close unwanted braces straightforward. 1+((()) won't reduce the stack of open braces, there will remain three open braces. It is difficult to tell a "compute as soon as possible" calculator what an empty pair of braces means: in 1+() the empty braces mean 0 (1+0=1) but in 1*() the empty braces mean 1 (1*1=1). Therefore you have to enter a corresponding number in order to close braces at the moment, e.g. 1+((0)) will do.
The percent operation works as "x percent of y". So if there is 37 on the display and you press the percent button and enter 123, you get as result 37% of 123.
If you press the [EE] button the display will never become 0e+ but 1e+ instead.
There is a simple plausibility check for the character choosen as thousand's separator: it must not be a number in the configured number base and for a decimal number base neither decimal point nor "e" (exponent identifier string) nor "-" (sign for negative numbers).