vc [-help] [-version]

This Perl script implements an RPN calculator that handles vectors of arbitrary dimensionality. It supports various arithmetic operations on vectors of compatible dimensions. It also supports unlimited undo/redo and basic macro programmability. Run with -help flag for more info.

This script requires a standard perl installation with the following standard packages: C<Getopt::Long>, C<strict>, C<vars>.

(C) 2002 by Ivan Neulander <ivan@rhythm.com>

All rights reserved. You may distribute this code under the terms of either the GNU General Public License or the Artistic License, as specified in the Perl README file.

(Run with -help option to get this from vc.) vc is an RPN calculator that supports multi-dimensional vector arithmetic. Each input line can be one of the following: 1) a constant: specified as a set of one or more comma- or space-separated floating-point numbers. e.g. 1 2 3 0> 1 2 3 2) a variable: specified by its user-assigned name. e.g. 0> 1 2 3 =a 0> 1 2 3 a 1> 1 2 3 0> 1 2 3 3) an operator: either a built-in or user-defined function. e.g. 1> 1 2 3 0> 4 5 6 . 0> 32 4) a sequence: a mix of the above, separated by spaces or commas; note that any constants will be interpreted as scalars if separated by spaces and vectors if separated by commas e.g. 1 2 3 4 + 2> 1 1> 2 0> 7 1,2 3,4 + 0> 4 6 The following is a list of vc's built-in operators. Some operators have synonyms, which are shown in braces {}. Some operators take a numeric argument; we represent this in the table with the metacharacter #. Other operator arguments are enclosed in metacharacters <>. General Control --------------- h Print this message { ? help } prompt Toggle prompt on and off q Quit {quit exit <ctrl-D> } u Undo last operation; more precisely, undo the last change to the stack { undo } U Reverse last undo { redo } rows# Show this many rows of stack Stack Operators --------------- [return] Duplicate last item (equivalent to c0) ddd... Drop last item for each "d" d# Drop item(s) specified, e.g. d2, d3-5 da Drop all items; clear stack s Swap last two items rrr... Rotate stack down for each r r# Rotate stack down specified number of times RRR... Rotate stack up for each R R# Rotate stack up specified number of times ccc... Copy last item for each "c" c# Copy item specified to end of stack, e.g. c3 c#-# Copy items specified to end of stack; e.g. c4-8 copies items 4 through 8 e.g. c8-4 copies items 4 through 8 in reverse order rev Reverse stack sort Sort stack by vector norm of each element count Number of items on stack (does not consume stack contents) ><file> Export contents of stack to file <file>; e.g. >stack <<file> Push contents of file <file> to stack; e.g. <stack Math Operators -------------- + Add last two items ++ Add all items - Subtract last item from second-last item * Multiply last two items ** Multiply all items ^ Raise second-last item to power of last item { pow } / Divide second-last item by last . Compute dot product of last two items { dot } x Compute cross product of last two items; dims of both must be 3 { cross } n Compute vector norm of last item { norm || } unit Normalize last item, i.e. it turn into a unit vector ang Compute vector angle between last two items { angle } proj Compute projection of second last item onto last trin Compute normal of triangle whose vertex positions are defined in CCW order by last 3 stack items rec Compute reciprocal of each element in last item sqrt Compute square root of each element in last item deg Use degrees for trig functions (default) rad Use radians for trig functions sin Compute sine of each element in last item cos Compute cosine of each element in last item tan Compute tangent of each element in last item pi Push pi on the stack asin Compute inverse sine of each element in last item acos Compute inverse cosine of each element in last item atan Compute inverse tangent of each element in last item log Compute natural log of each element in last item exp Compute e raised to power of each element in last item sinh Compute hyperbolic sine of each element in last item cosh Compute hyperbolic cosine of each element in last item tanh Compute hyperbolic tangent of each element in last item asinh Compute inverse hyp sine of each element in last item acosh Compute inverse hyp cosine of each element in last item atanh Compute inverse hyp tangent of each element in last item rand# Push vector of # dimensions with each element a random value in [0,1). E.g. rand3 Special Operators ----------------- !!!... Repeat last input line for each ! !# Repeat last input line the specified number of times e#,#,... Extract specified components from last item, e.g. e1,3,4 split Split vector into set of component scalars {spl} cat# Concatenate items in last n items into a single vector. If no number is given, assume n=2; if n=0 concatenate all. cat* Concatenate all entries. {cat0} <op>l Apply specified two-argument operation to each item but last, using the last item as the second argument; <op> may be one of (+ - * / ^); e.g. -l subtracts the last item from every other item { <op>last } clear Clear all memory: stack, undo, user-defined variables and functions {cl} Variable Operators -------------------- =<var> Assign last item to variable <var>. Does not consume last item. e.g. =a -><var> Assign last item to variable <var>. Consumes last item. e.g. ->a ~<var> Clear variable <var> from memory; no effect on stack vars Print list of defined variables Function Operators ------------------ funcs Print list of defined functions ~<func> Clear function <func> from memory; no effect on stack <func> = <operators> [ see below ] <func>(<x>,<y>,...) = <operators> [ see below ] This creates the user defined function <func>, with or without parameters. Parameters, if any, are consumed from the stack. Parameters will not clash with user variables. To define local variables, which do not clash with any other variables, prefix them with an underscore (e.g. example 7). Functions that do not have formal parameters may still access implicit parameters on the stack (e.g. examples 2,4,6). Examples: 1. midpoint(a,b) = a b + 2 / 2. midpoint = + 2 / 3. distance(x,y) = x y - n 4. distance = - n 5. percentChange(from,to) = to from / 1 - 6. percentChange = swap / 1 - 7. avg = count ->_sum ++ _sum / Functions may call one another but not recursively.

Categories: Educational Scientific Math