See also Functions for the syntax for creating your own functions.
| abs | absolute value |
| acos | arc cosine |
| acosh | hyperbolic arc cosine |
| acot | arc cotangent |
| acsc | arc cosecant |
| add_object | replace deleted graphics object |
| arb | arbitrary element |
| as_string | return given argument as a string |
| asec | arc secant |
| asin | arc sine |
| asinh | hyperbolic arc sine |
| atan | arc tangent |
| atanh | hyperbolic arc tangent |
| ceil | ceiling (smallest integer greater than given number) |
| char | character of given index in ASCII character set |
| char_mult | magnify graphics object (not implemented in ISETLW) |
| clear_screen | clear graphics screen and delete current graphs |
| close | close an opened file |
| cos | cosine |
| cosh | hyperbolic cosine |
| cot | cotangent |
| csc | cosecant |
| del_object | delete current graphics object |
| delay | wait a given number of seconds |
| den | denominator of a rational |
| domain | set of map first coordinates |
| draw | draw a line |
| eof | test for end of file |
| erasable | erase graphing |
| even | test for even integer |
| exp | exponential |
| fix | return given number as an integer |
| float | return given number in scientific notation or as real |
| floor | largest value smaller than given number |
| get_coord | return coordinates and keypress during graphics |
| hi | highest index of a tuple |
| image | set of map second components |
| is_atom | test for atom |
| is_boolean | test for boolean |
| is_defined | test to see if expression has a value |
| is_file | test to see if it's an open file |
| is_floating | test for real number / float |
| is_func | test to see if it's a function or procedure |
| is_integer | test for integer |
| is_map | test for map |
| is_number | test to see if numeric |
| is_om | test to see if expression is undefined |
| is_rational | test for rational |
| is_set | test for set |
| is_string | test for string |
| is_tuple | test for tuple |
| ln | natural logarithm |
| lo | lowest index of a tuple |
| load_graph | load a graph |
| log | common logarithm |
| max | larger of two values |
| max_line | number of columns to use during output |
| min | smaller of two values |
| move | move to specified graphics coordinates |
| new_object | start a new graphics object |
| npow | set of subsets of specified cardinality |
| num | numerator of a rational |
| odd | test for odd integer |
| opena | open a file for apending |
| openr | open a file for reading |
| openw | open a file for writing |
| ord | integer index of given character in ASCII character set |
| origin | sets lowest index of a tuple |
| point | draw point or square in graphics window |
| pow | power set of a set (set of subsets) |
| precision | precision of decimal output |
| random | select a random element |
| randomize | seed the random number generator |
| rectangle | draw rectangle in the graphics window |
| resolution | graphics resolution based on scale |
| save_graph | save current graph |
| scale | set graphics scale |
| sec | secant |
| sgn | sign of given number |
| sin | sine |
| sinh | hyperbolic sine |
| sqrt | square root |
| system | send a command to DOS (not implemented in ISETLW) |
| tan | tangent |
| tanh | hyperbolic tangent |
| textout | write text to the graphics window |
| thickline | set thickness of lines in graphics window |
| title_window | draw a title in the graphics window |
| video | control how ISETL for DOS displays video (not ISETLW) |
| where_am_I | current drawing coordinates |
| XtoYration | aspect ration of graphics window |