math::polynomials(3tcl) Tcl Math Library math::polynomials(3tcl)
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NAME
math::polynomials - Polynomial functions
SYNOPSIS
package require Tcl ?8.3?
package require math::polynomials ?1.0.1?
::math::polynomials::polynomial coeffs
::math::polynomials::polynCmd coeffs
::math::polynomials::evalPolyn polynomial x
::math::polynomials::addPolyn polyn1 polyn2
::math::polynomials::subPolyn polyn1 polyn2
::math::polynomials::multPolyn polyn1 polyn2
::math::polynomials::divPolyn polyn1 polyn2
::math::polynomials::remainderPolyn polyn1 polyn2
::math::polynomials::derivPolyn polyn
::math::polynomials::primitivePolyn polyn
::math::polynomials::degreePolyn polyn
::math::polynomials::coeffPolyn polyn index
::math::polynomials::allCoeffsPolyn polyn
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DESCRIPTION
This package deals with polynomial functions of one variable:
o the basic arithmetic operations are extended to polynomials
o computing the derivatives and primitives of these functions
o evaluation through a general procedure or via specific proce-
dures)
PROCEDURES
The package defines the following public procedures:
::math::polynomials::polynomial coeffs
Return an (encoded) list that defines the polynomial. A polyno-
mial
f(x) = a + b.x + c.x**2 + d.x**3
can be defined via:
set f [::math::polynomials::polynomial [list $a $b $c $d]
list coeffs
Coefficients of the polynomial (in ascending order)
::math::polynomials::polynCmd coeffs
Create a new procedure that evaluates the polynomial. The name
of the polynomial is automatically generated. Useful if you need
to evualuate the polynomial many times, as the procedure con-
sists of a single [expr] command.
list coeffs
Coefficients of the polynomial (in ascending order) or
the polynomial definition returned by the polynomial com-
mand.
::math::polynomials::evalPolyn polynomial x
Evaluate the polynomial at x.
list polynomial
The polynomial's definition (as returned by the polyno-
mial command). order)
float x
The coordinate at which to evaluate the polynomial
::math::polynomials::addPolyn polyn1 polyn2
Return a new polynomial which is the sum of the two others.
list polyn1
The first polynomial operand
list polyn2
The second polynomial operand
::math::polynomials::subPolyn polyn1 polyn2
Return a new polynomial which is the difference of the two oth-
ers.
list polyn1
The first polynomial operand
list polyn2
The second polynomial operand
::math::polynomials::multPolyn polyn1 polyn2
Return a new polynomial which is the product of the two others.
If one of the arguments is a scalar value, the other polynomial
is simply scaled.
list polyn1
The first polynomial operand or a scalar
list polyn2
The second polynomial operand or a scalar
::math::polynomials::divPolyn polyn1 polyn2
Divide the first polynomial by the second polynomial and return
the result. The remainder is dropped
list polyn1
The first polynomial operand
list polyn2
The second polynomial operand
::math::polynomials::remainderPolyn polyn1 polyn2
Divide the first polynomial by the second polynomial and return
the remainder.
list polyn1
The first polynomial operand
list polyn2
The second polynomial operand
::math::polynomials::derivPolyn polyn
Differentiate the polynomial and return the result.
list polyn
The polynomial to be differentiated
::math::polynomials::primitivePolyn polyn
Integrate the polynomial and return the result. The integration
constant is set to zero.
list polyn
The polynomial to be integrated
::math::polynomials::degreePolyn polyn
Return the degree of the polynomial.
list polyn
The polynomial to be examined
::math::polynomials::coeffPolyn polyn index
Return the coefficient of the term of the index'th degree of the
polynomial.
list polyn
The polynomial to be examined
int index
The degree of the term
::math::polynomials::allCoeffsPolyn polyn
Return the coefficients of the polynomial (in ascending order).
list polyn
The polynomial in question
REMARKS ON THE IMPLEMENTATION
The implementation for evaluating the polynomials at some point uses
Horn's rule, which guarantees numerical stability and a minimum of
arithmetic operations. To recognise that a polynomial definition is
indeed a correct definition, it consists of a list of two elements: the
keyword "POLYNOMIAL" and the list of coefficients in descending order.
The latter makes it easier to implement Horner's rule.
BUGS, IDEAS, FEEDBACK
This document, and the package it describes, will undoubtedly contain
bugs and other problems. Please report such in the category math ::
polynomials of the Tcllib Trackers [http://core.tcl.tk/tcllib/re-
portlist]. Please also report any ideas for enhancements you may have
for either package and/or documentation.
When proposing code changes, please provide unified diffs, i.e the out-
put of diff -u.
Note further that attachments are strongly preferred over inlined
patches. Attachments can be made by going to the Edit form of the
ticket immediately after its creation, and then using the left-most
button in the secondary navigation bar.
KEYWORDS
math, polynomial functions
CATEGORY
Mathematics
COPYRIGHT
Copyright (c) 2004 Arjen Markus <arjenmarkus@users.sourceforge.net>
tcllib 1.0.1 math::polynomials(3tcl)