mathomatic/lib

                       Mathomatic Symbolic Math Library
                       --------------------------------

This directory contains the API (Application Programming Interface) "lib.c"
and test/example programs "testmain.c" and "example.c" for the Mathomatic
symbolic math library. The API can be used to link your C compatible programs
with the Mathomatic symbolic math engine. This simple API provides for
passing C text strings containing expressions and commands to the Mathomatic
engine. If successful, a text string containing the resulting expression is
returned, otherwise an error message is returned.

Mathomatic is released under the GNU Lesser General Public License, so that
even closed-source software can make use of it.

This symbolic math library is at least able to be run anywhere the main
Mathomatic application can be run, and does not require an operating system
beyond the ability to allocate memory with malloc(3). The symbolic math
library is not re-entrant, meaning it cannot successfully be called again
until the last call to it completes. This is due to the fact that most data
storage areas in Mathomatic are global and static. I think that also means
Mathomatic is not threadsafe, correct me if I am wrong.

If you are trying to use this library as a plotting engine, please don't.
Every numerical calculation requires a memory move of half of the entire
expression for each and every number in it, to simplify a numerical
expression in Mathomatic. This will make 3D plots impossible and 2D plots
very slow. You need a library that parses to an expression tree and evaluates
that. Package "libmatheval1" will do this for you. It is available at

http://www.gnu.org/software/libmatheval/

and is free software that is currently maintained as of 2011.

To compile the Mathomatic symbolic math library and its test program, type
"make" while in this "lib" directory. This will create the static library
"libmathomatic.a" and the API test executable named "testmain". To run the
test executable, type "./testmain".

To do a system install of the development library "libmathomatic.a" and C
header file "mathomatic.h", type:

	make flush
	make
	sudo make install

and enter your password. There are no tests, because the library uses the
same code as the Mathomatic application. If the application passes all tests,
the library should work too. "testmain" will successfully "read" in most of
the standard tests with the read command, until it encounters a calculate
command, which doesn't exist in the library, causing the read to terminate.

Just include the file "mathomatic.h" and call the functions in "lib.c" to use
this library. Link your program with "libmathomatic.a" by using "-lmathomatic
-lm" at the end of the ld linker command line. "libmathomatic.a" is not
required on the target system, since it is a static library, meaning it is
included in the resulting executable as needed.

The following code provides a quick test of this library:

    char *output;
    matho_init();
    matho_parse("x^2=4", NULL);
    matho_process("solve x", &output);
    printf("%s\n", output);

Remember to free(output) on each successful call to matho_process() and
matho_parse() to return the memory used by the output string when you are
finished using it, otherwise there will be a memory leak. Here is the above
code fixed properly so it doesn't leak:

    char *output;
    int rv;
    if (!matho_init()) {
        printf("Not enough memory.\n");
        exit(1);
    }
    matho_parse("x^2=4", NULL);
    rv = matho_process("solve x", &output);
    if (output) {
        printf("%s\n", output);
        if (rv) {
            free(output);
        } else {
            printf("Error return.\n");
        }
    }

The above code is in the file "example.c" and the result of running the above
code when linked with the Mathomatic library should be:

	x = 2*sign

The following Mathomatic commands are omitted in this library: calculate,
edit, plot, push, quit, and tally. To make up for the lack of the calculate
command, the replace, approximate, and "simplify sign" commands are provided,
allowing very similar functionality.

This paragraph is old information, you can now specify the integrate bounds
on the command-line. Recently, the "nintegrate" and "integrate definite"
commands are allowed; the bounds of integration are specified in the two
equation spaces following the current equation. cur_equation+1 is the lower
bound, and cur_equation+2 is the upper bound. Of course, the integrate and
nintegrate commands operate on the current equation, specified by the global
"cur_equation" variable (origin 0). The equation number displayed is always
origin 1, making it 1 greater than "cur_equation", so keep that in mind.

Please define the C preprocessor name HANDHELD=1 when compiling this library
for handheld computing devices like the iPhone and other small computing
devices, for reduced memory usage. For embedded devices with no file storage,
or for privacy or no wish to use file storage, define SECURE=1 too.

Please read the file "../README.txt" for more developer information. These
files were written by George Gesslein II of www.mathomatic.org