Is it possible to use as a library?

[ghost]

Like libqalculate?

https://github.com/Qalculate/libqalculate

[lcn2]

Yes, calc builds libraries from which you can link operations.

See the file LIBRARY for detailed information or run the calc command:

; help libcalc

In addition, nearly all help files for builtin functions contains a section called "LINK LIBRARY" that lists the libcalc functions that as needed to perform the function. For example:

; help sin

Calc comes with 2 examples of programs that link to libcalc. See the file sample.README and the source files sample_many.c and sample_rand.c for two examples of this.

[lcn2]

BTW: Calc does have a custom interface for those who wish to call their own code within the calc framework.

See the file custom/CUSTOM_CAL or run the calc command:

; new_custom

The entire custom/ tree is devoted to examples of custom functions. Moreover when you install calc, there is a separate library libcustcalc that contains those custom function examples and whatever other code you may have linked into that system.

Some people use the custom interface to access custom hardware accelerators, for example. Other people write special calculation operations to improve the algorithmic performance or to make use of an external mathematical library within the calc framework.