QALC man page

The program will start in interactive mode if no expression and no file is specified (or interactive mode is explicitly selected).

Commands for RPN mode:

When a line begins with '/', the text that follows is always interpreted as a command.

Algebraic mode:

Calculation:

Enabled objects:

Generic display options:

Numerical display:

Parsing:

Units:

Other:

Numbers
These are the regular numbers composed by digits 0-9 and a decimal sign — a dot, or a comma if it is the default decimal point in the locale/language used. If comma is used as decimal sign, the dot is still kept as an alternative decimal sign, if not explicitly deactivated. Numbers include integers, real numbers, and complex numbers. The imaginary part of complex numbers are written with as regular number followed by the special variable "i" (can be changed to a "j"), which represents the square root of -1. Spaces between digits are ignored ("5 5 = 55"). "E" (or "e") can be considered as a shortcut for writing many zeroes and is equivalent to multiplication by 10 raised to the power of the right-hand value (e.g. "5E3 = 5000"). Sexagesimal numbers (and time) can be entered directly using colons (e.g. "5:30 = 5.5"). A number immediately preceded "0b", "0o", "0d" or "0x" are interpreted as a number with base 2, 8, 12 or 16, respectively (e.g. "0x3f = 63").

Intervals
A number interval can be entered using the interval() function, the uncertainty() function, or using "±" or "+/-" (e.g. 5±1 = uncertainty(5, 0.2) = interval(4, 6)). If the read precision option is activated, decimal numbers are interpreted as an interval between the numbers that are normally rounded to the entered number (e.g. 1.1 = 1.1±0.05). If interval calculation using variance formula is activated (default), the interval represents the standard uncertainty (deviation) of the value.

Vectors and Matrices
A matrix is a two-dimensional rectangular array of mathematical objects. Vectors are matrices with only one row or column, and thus one-dimensional sequences of objects. Vectors and matrices are generated by various functions, or using syntax in the form of [1 2 3 4] and [1 2; 3 4], with columns separated by space or comma and rows separated by semi-colon, or (1, 2, 3, 4) and ((1, 2), (3, 4)). A vector with sequence of numbers can be created using "..." (e.g. "1...4"), or colon (e.g. "[1:4]", or "[1:1:4]" where the second value specifies the increment).

Variables/Constants
See the list of variables in the GUI manual or using the command .I list variables

Functions
See the list of functions in the GUI manual or using the command .I list functions

Units and Prefixes
See the list of units and prefixes in the GUI manual or using the command .I list units. Abbreviated, plural and singular forms of unit names and prefixes are generally allowed. Prefixes must be put immediately before the unit to be interpreted as prefixes (eg. 5 mm = 0.005 m, but 5 m m = 5 m^2). For convenience units allow the power operator to be left out (e.g. 5 m2 = 5 m^2), with currencies excluded.

Unknowns
Unknowns are text strings without any associated value. These are temporary unknown variables with default assumptions. Unknowns can also be explicitly entered by placing a backslash (\) before a single character (e.g. 5\a + 2\b) or using quotation mark before and after a text string (e.g. 5 "apples" + 2 "bananas"). If unknowns are activated characters without any associated variable, function or unit in an expression, will be regarded as an unknown variable.

Date and Time
Date/time values are specified using quoted text string (quotation marks are not needed for function arguments), using standard date and time format (YYYY-MM-DDTHH:MM:SS). Some local formats are also supported, but not recommended. The local time zone are used, unless a time zone is specified at the end of the time string (Z/UTC/GMT or +/-HH:MM). Date/time supports a small subset of arithmetic operations. The time units represents calendar time, instead of average values, when added or subtracted to a date.

Text
This category represent a number of different function argument types, such as regular text and file names. They can, but do not need to be put in quotes except when containing the argument separator.

Comments
All text after a hashtag (e.g. (5*2)/2 #calculating triangle area) is treated as a comment.

Operations and operators (word operators such as AND must be surrounded by space):

Addition (+)

Subtraction (-)

Multiplication (*)

Division (/)

Remainder (%, rem) and modulo (%%, mod)
Returns the remainder after division.

Integer division (//, div)
Rounds the result of division towards zero.

Exponentiation (^, **)
Note that x^y^z equals x^(y^z), and not (x^y)^z. Note also that for non-integer exponents with negative bases, the principal root is returned and not the real root ((-8)^(1/3) equals 1 + 1.73i, and not -2). To calculate the real root for negative values, use the cbrt() and root() functions.

10^x (E)

Parenthesis ((, ))

Parellel sum (∥, ||)
Returns the the reciprocal value of a sum of reciprocal values. || is interpreted as parallel if units are used, otherwise as logical OR.

Logical operators (!, NOT, ||, OR, &&, AND, XOR, NOR, NAND)

Bitwise operators (~, |, &, <<, >>, XOR)

Comparison operators (=, !=, <, <=, >, >=)
Returns 1 if expression is true and 0 if false. The x variable is isolated if the expression does not evaluate as true or false. Primarily used for equations and inequalities.

Dot product (.)

Element-wise operators (.*, ./, .^)

Save operator (:=, =)
Saves the expression to the right of the operator as a variable or function (e.g. var1:=5, func1():=x+y, var1=ln(5)+2). If the colon is omitted the expression is calculated before it is assigned to the variable.

Evaluation priority order: parenthesis, 10^x, exponentiation, functions, bitwise NOT, logical NOT, multiplication/division/remainder, parallel sum, addition/subtraction, bitwise NOT, bitwise shift, comparisons, bitwise AND, bitwise XOR, bitwise OR, logical AND, logical OR.

The evaluation of short/implicit multiplication without any multiplication sign (e.g. 5x, 5(2+3)), differs depending on the parsing mode. In the conventional mode implicit multiplication does not differ from explicit multiplication (12/2(1+2) = 12/2*3 = 18, 5x/5y = 5 * x/5 * y = xy). In the parse implicit multiplication first mode, implicit multiplication is parsed before explicit multiplication (12/2(1+2) = 12/(2 * 3) = 2, 5x/5y = (5 * x)/(5 * y) = x/y). The default adaptive mode works as the parse implicit multiplication first mode, unless spaces are found (1/5x = 1/(5 * x), but 1/5 x = (1/5) * x). In the adaptive mode unit expressions are parsed separately (5 m/5 m/s = (5 * m)/(5 * (m/s)) = 1 s). Function arguments without parentheses are an exception, where implicit multiplication in front of variables and units is parsed first regardless of mode (sqrt 2x = sqrt(2x)).

In chain mode, expressions are calculated from left to right, ignoring standard order of operations, like the immediate execution mode of a traditional calculator (1+2*3 = (1+2)*3 = 9).

The "to"-operator is used for unit conversion and manipulation of how the result is presented. Place " to " or a right arrow (e.g. "->") followed by one of expressions/commands listed below, at the end of an expression.

Similarly where (or alternatively "/.") can be used at the end (but before "to"), for variable assignments, function replacements, etc. (e.g. "x+y where x=1 and y=2", "x^2=4 where x>0", and "sin(5) where sin()=cos()"). Variables assignments can also be placed before the expression, separated by comma, e.g. <quote>x=1, y=2, x+y</quote>, but this syntax is more strict.

Note that to and where can only be applied to the whole expression. Everything before the operator is always treated as the expression to convert (or apply replacement to), and everything after as the conversion/replacement expression, regardless of any parentheses.

Basic functions and operators

Units

Physical constants

Uncertainty and interval arithmetic
result with interval arithmetic activated is shown in parenthesis

Algebra

Calculus

Matrices and vectors

Statistics

Time and date

Number bases