Platform-dependent packages

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GetYacasPID -- obtain Yacas process number

Unix-specific add-on

Calling format:

GetYacasPID()

Description:

Requires: a Unix shell.

Example:

In> GetYacasPID()
Out> 26456;

See also:

---

ShowPS -- view equations graphically

Unix-specific add-on

Calling format:

ShowPS(expr)

Parameters:

Description:

Requires: a Unix shell, latex, dvips, gv or another Postscript viewer.

Example:

In> [ PSViewCommand := "ghostview"; \
  ShowPS(x+2*Sin(x)); ]
Expression exported as /tmp/yacas-tmp
file-28802.tex
Out> True;

See also:

---

MakeFunctionPlugin -- compile numerical functions into plugins

Unix-specific add-on

Calling format:

MakeFunctionPlugin("name", body)

Parameters:

body -- expression, function of arguments, must evaluate to a function of some variables.

Description:

Requires: a Unix shell, a compiler named c++ with ELF .so support, Yacas headers in FindFile("")/include; current directory must be writable.

The body expression must be a CForm()-exportable function of the arguments and may contain numerical constants. Pi is allowed and will be converted to floating-point.

All arguments and the return value of the function are assumed to be double precision real numbers. The result of passing a non-numerical argument will be an unevaluated expression.

Example: In> MakeFunctionPlugin("f1", {x,y}, Sin(x/y)) Function f1(x,y) loaded from plugins.tmp/libf1_plugin_cc.so Out> True; In> f1(2,3) Out> 0.618369803069736989620253; In> f1(x,5) Out> f1(x,5);

The function creates the following files in subdirectory plugins.tmp/ of current directory:

• f1_plugin.h, f1_plugin.cc -- C++ code of the plugin; the function in the above example is implemented in C++ as

  double f1_plugin_cc(double x, double y) { return sin(x/y); }

• f1_plugin.stub -- Yacas-language stub
• f1_plugin_api.cc -- Yacas-generated C++ stub
• f1_plugin_api.description - Yacas-generated documentation
• f1_plugin.compile -- command line to compile
• libf1_plugin_cc.so -- compiled plugin Note that all files have names matching "*_plugin*".

After creating these files, MakeFunctionPlugin() will:

• Run a c++ compiler command; if compilation fails, all error messages will appear on the screen;
• Load resulting .so object with DllLoad();
• Print an information message on success.

If you call MakeFunctionPlugin() repeatedly to define a function with the same name, old files will be overwritten and old libraries will be unloaded with DllUnload().

See also:

---

Version -- show version of Yacas

Internal function

Calling format:

Version()

Description:

Examples:

In> Version()
Out> "1.0.48rev3";
In> LessThan(Version(), "1.0.47")
Out> False;
In> GreaterThan(Version(), "1.0.47")
Out> True;

The last two calls show that the LessThan and GreaterThan functions can be used for comparing version numbers. This method is only guaranteed, however, if the version is always expressed in the form d.d.dd as above.

See also:

---

Vi -- edit a file or function

Unix-specific add-on

Calling format:

Vi(filename);
Vi(functionname);

Parameters:

functionname - name of a function to find for editing

Description:

It finds the function by scanning the *.def files that have been reported to the system. (Vi calls FindFunction for this.) If editing a function, the command will jump directly to the first occurrence of the name of the function in the file (usually the beginning of a definition of a function).

For Vi() to be really useful, you need to start Yacas from the scripts/ directory in the development tree. In that case, FindFunction() will return the filename under that directory. Otherwise, FindFunction() will return a name in the systemwide installation directory (or directory specified in the --rootdir option).

Examples:

In> Vi("yacasinit.ys")
Out> True;
In> Vi("Sum")
Out> True;

See also: