Basic

AskButtons
AskButtons (query)
AskButtons (query, button1, ...)

Asks a question and presents a list of buttons to the user (or a menu of options in text mode). Returns the 1-based index of the button pressed. That is, returns 1 if the first button was pressed, 2 if the second button was pressed, and so on. If the user closes the window (or simply hits enter in text mode), then null is returned. The execution of the program is blocked until the user responds.

Version 1.0.10 onwards.

AskString
AskString (query)
AskString (query, default)

Asks a question and lets the user enter a string, which it then returns. If the user cancels or closes the window, then null is returned. The execution of the program is blocked until the user responds. If default is given, then it is pre-typed in for the user to just press enter on (version 1.0.6 onwards).

Compose
Compose (f,g)

Compose two functions and return a function that is the composition of f and g.

ComposePower
ComposePower (f,n,x)

Compose and execute a function with itself n times, passing x as argument. Returning x if n equals 0. Example:

genius> function f(x) = x^2 ;
genius> ComposePower (f,3,7)
= 5764801
genius> f(f(f(7)))
= 5764801

Evaluate
Evaluate (str)

Parses and evaluates a string.

GetCurrentModulo
GetCurrentModulo

Get current modulo from the context outside the function. That is, if outside of the function was executed in modulo (using mod) then this returns what this modulo was. Normally the body of the function called is not executed in modular arithmetic, and this builtin function makes it possible to make GEL functions aware of modular arithmetic.

Identity
Identity (x)

Identity function, returns its argument. It is equivalent to function Identity(x)=x.

IntegerFromBoolean
IntegerFromBoolean (bval)

Make integer (0 for false or 1 for true) from a boolean value. bval can also be a number in which case a non-zero value will be interpreted as true and zero will be interpreted as false.

IsBoolean
IsBoolean (arg)

Check if argument is a boolean (and not a number).

IsDefined
IsDefined (id)

Check if an id is defined. You should pass a string or and identifier. If you pass a matrix, each entry will be evaluated separately and the matrix should contain strings or identifiers.

IsFunction
IsFunction (arg)

Check if argument is a function.

IsFunctionOrIdentifier
IsFunctionOrIdentifier (arg)

Check if argument is a function or an identifier.

IsFunctionRef
IsFunctionRef (arg)

Check if argument is a function reference. This includes variable references.

IsMatrix
IsMatrix (arg)

Check if argument is a matrix. Even though null is sometimes considered an empty matrix, the function IsMatrix does not consider null a matrix.

IsNull
IsNull (arg)

Check if argument is a null.

IsString
IsString (arg)

Check if argument is a text string.

IsValue
IsValue (arg)

Check if argument is a number.

Parse
Parse (str)

Parses but does not evaluate a string. Note that certain pre-computation is done during the parsing stage.

SetFunctionFlags
SetFunctionFlags (id,flags...)

Set flags for a function, currently "PropagateMod" and "NoModuloArguments". If "PropagateMod" is set, then the body of the function is evaluated in modular arithmetic when the function is called inside a block that was evaluated using modular arithmetic (using mod). If "NoModuloArguments", then the arguments of the function are never evaluated using modular arithmetic.

SetHelp
SetHelp (id,category,desc)

Set the category and help description line for a function.

SetHelpAlias
SetHelpAlias (id,alias)

Sets up a help alias.

chdir
chdir (dir)

Changes current directory, same as the cd.

CurrentTime
CurrentTime

Returns the current UNIX time with microsecond precision as a floating point number. That is, returns the number of seconds since January 1st 1970.

Version 1.0.15 onwards.

display
display (str,expr)

Display a string and an expression with a colon to separate them.

DisplayVariables
DisplayVariables (var1,var2,...)

Display set of variables. The variables can be given as strings or identifiers. For example:

DisplayVariables(`x,`y,`z)
	    

If called without arguments (must supply empty argument list) as

DisplayVariables()
	    

then all variables are printed including a stacktrace similar to Show user variables in the graphical version.

Version 1.0.18 onwards.

error
error (str)

Prints a string to the error stream (onto the console).

exit
exit

Aliases: quit

Exits the program.

false
false

Aliases: False FALSE

The false boolean value.

manual
manual

Displays the user manual.

print
print (str)

Prints an expression and then print a newline. The argument str can be any expression. It is made into a string before being printed.

printn
printn (str)

Prints an expression without a trailing newline. The argument str can be any expression. It is made into a string before being printed.

PrintTable
PrintTable (f,v)

Print a table of values for a function. The values are in the vector v. You can use the vector building notation as follows:

PrintTable (f,[0:10])
	    

If v is a positive integer, then the table of integers from 1 up to and including v will be used.

Version 1.0.18 onwards.

protect
protect (id)

Protect a variable from being modified. This is used on the internal GEL functions to avoid them being accidentally overridden.

ProtectAll
ProtectAll ()

Protect all currently defined variables, parameters and functions from being modified. This is used on the internal GEL functions to avoid them being accidentally overridden. Normally Genius Mathematics Tool considers unprotected variables as user defined.

Version 1.0.7 onwards.

set
set (id,val)

Set a global variable. The id can be either a string or a quoted identifier. For example:

set(`x,1)
	    

will set the global variable x to the value 1.

The function returns the val, to be usable in chaining.

SetElement
SetElement (id,row,col,val)

Set an element of a global variable which is a matrix. The id can be either a string or a quoted identifier. For example:

SetElement(`x,2,3,1)
	    

will set the second row third column element of the global variable x to the value 1. If no global variable of the name exists, or if it is set to something that's not a matrix, a new zero matrix of appropriate size will be created.

The row and col can also be ranges, and the semantics are the same as for regular setting of the elements with an equals sign.

The function returns the val, to be usable in chaining.

Available from 1.0.18 onwards.

SetVElement
SetElement (id,elt,val)

Set an element of a global variable which is a vector. The id can be either a string or a quoted identifier. For example:

SetElement(`x,2,1)
	    

will set the second element of the global vector variable x to the value 1. If no global variable of the name exists, or if it is set to something that's not a vector (matrix), a new zero row vector of appropriate size will be created.

The elt can also be a range, and the semantics are the same as for regular setting of the elements with an equals sign.

The function returns the val, to be usable in chaining.

Available from 1.0.18 onwards.

string
string (s)

Make a string. This will make a string out of any argument.

true
true

Aliases: True TRUE

The true boolean value.

undefine
undefine (id)

Alias: Undefine

Undefine a variable. This includes locals and globals, every value on all context levels is wiped. This function should really not be used on local variables. A vector of identifiers can also be passed to undefine several variables.

UndefineAll
UndefineAll ()

Undefine all unprotected global variables (including functions and parameters). Normally Genius Mathematics Tool considers protected variables as system defined functions and variables. Note that UndefineAll only removes the global definition of symbols not local ones, so that it may be run from inside other functions safely.

Version 1.0.7 onwards.

unprotect
unprotect (id)

Unprotect a variable from being modified.

UserVariables
UserVariables ()

Return a vector of identifiers of user defined (unprotected) global variables.

Version 1.0.7 onwards.

wait
wait (secs)

Waits a specified number of seconds. secs must be non-negative. Zero is accepted and nothing happens in this case, except possibly user interface events are processed.

Since version 1.0.18, secs can be a noninteger number, so wait(0.1) will wait for one tenth of a second.

version
version

Returns the version of Genius as a horizontal 3-vector with major version first, then minor version and finally the patch level.

warranty
warranty

Gives the warranty information.