libunits Files

This library provides the posibility of calculation with units in a standard c-program.

For a small calculator using this feature, take a look to the PRPN project:
https://sourceforge.net/projects/libunits/files/prpn/
https://github.com/sengebusch/prpn


Also take a look into the ChangeLog and INSTALL files for more information.

The database inclued all SI bases and some additional pseudo bases:


	The currently used bases are:
        + SI bases are:
          - mass: 				kg	(kilo grams)
  	  - length: 				m	(meter)
	  - time:				s	(second)
	  - current:				A	(Ampere)
	  - temperatur:				K	(Kelvin)
	  - lightforce:				cd	(candela)
	  - amount of substance, quanity:	mol	(Mol)	

        + The used SI certified pseudo bases are:
          - flat angle:				rad	(radian)
	  - solid angle:			sr	(steradiant)

        + The included non SI certified pseudo bases are:
	  - storage (computer)			bit	(bit)
	  - currency				EUR	(Euro)
	  - ratio				:1	(to one)
	  - logarythmic ratio, 10*lg		dBm	(deci Bel)
	  - logarythmic ratio, 20*lg		dBu	(deci Bel)
	  - pixel number			pix	(pixel)


For a simple user interface, it provides an api with the following commands:


  	  int u_open (void)
		initialize the database and the the global pointer
        	MUST be used before any other function of the library is
	        called!

 	  u_close (void)	
		detach from the database

	  struct U_VALUE u_add (struct U_VALUE value1, struct U_VALUE value2)
		= value1 + value2

	  struct U_VALUE u_sub (struct U_VALUE value1, struct U_VALUE value2)
 		= value1 - value2

	  struct U_VALUE u_mult (struct U_VALUE value1, struct U_VALUE value2)
		= value1 * value2

	  struct U_VALUE u_div (struct U_VALUE value1, struct U_VALUE value2)
		= value1 / value2

	  struct U_VALUE u_pow (struct U_VALUE value1, struct U_VALUE value2)
		= pow (value1, value2)

	  struct U_VALUE u_log (struct U_VALUE value1, struct U_VALUE value2)
		= log (value1) / log (value2)

	  struct U_VALUE u_sin (struct U_VALUE value1)
		= sin (value1)

	  struct U_VALUE u_cos (struct U_VALUE value1)
		= cos (value1)

	  struct U_VALUE u_tan (struct U_VALUE value1)
		= sin (value1) / cos (value1)

	  struct U_VALUE u_abs (struct U_VALUE value1)
                calculate the complex absolute value 
		without changing the unit

	  struct U_VALUE u_cpy (struct U_VALUE *dest, struct U_VALUE source)
		copy "source" to "dest"

	  struct U_VALUE u_conv (struct U_VALUE dest, const char *unit)
		convert "dest" to the unit "unit". 
	        On error the status is set to  UNIT_ERR_not_same_dimension

	  struct U_VALUE u_atou (const char *source);
        	convert a string like "1.5_m^2" to U_VALUE

	  struct U_VALUE u_fatou (const long double source, const char *unit)
        	add a unit to a floating point variable

	  struct U_VALUE u_ftou (const long double source)
        	convert a floating point to a dimensionless U_VALUE

	  double u_utofa (struct U_VALUE value, char *dest)
        	convert a U_VALUE to a floationg point and a string

	  double u_utof (struct U_VALUE value, const char *unit);
        	convert a U_VALUE to a floationg point with the unit "unit"
	        On error the status is set to  UNIT_ERR_not_same_dimension

	  int u_sprintf (char *dest, const char *format, struct U_VALUE value)
        	print the value in a string.
	        The format must include a "%f", "%g" or "%e" AND a "%s", e.g.
	        u_sprintf (dest, "the result is %9.3f %s\n", value);

	  int u_printf (const char *format, struct U_VALUE value)
        	like u_sprintf on stdout

	  int u_error (char *dest, struct U_VALUE value)
        	checks the value for error.
                returns a value > 0, if an error was recognized
		if *dest is not NULL, a clear text description of the error
                is given



PRPN:
This small calculator uses the libunits library to do calculations 

It uses ncurses for ui.


STK2 sca C deg aut dBm  nrm  dec alg  (0)   crt cmp tec   SI M= 0         
-----------------------------------------------------------------
|                                               |10             |
|                                               | 9             |
|                                               | 8             |
|                                               | 7             |
|                                               | 6             |
|                                               | 5             |
|                                               | 4             |
|                              1  V             | 3   R         |
|                              3  A             | 2   R         |
|                    333.3333333  mOhm          | 1   R         |
-----------------------------------------------------------------
electrical resistance (R): milliohms
1_V / 3_A =