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// Copyright (C) 2005 Pino Toscano <toscano.pino@tiscali.it>
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// This program is free software; you can redistribute it and/or
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// modify it under the terms of the GNU General Public License
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// as published by the Free Software Foundation; either version 2
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// of the License, or (at your option) any later version.
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// You should have received a copy of the GNU General Public License
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// along with this program; if not, write to the Free Software
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// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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#ifndef KIG_EQUATION_H
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#define KIG_EQUATION_H
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* Simple class that represents an equation.
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* It does not do any calculation, it serves only as a helper to write
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* equations like \f$ 7 xy + 3 y^2 - 5 x - 2 y + 8 = 0 \f$ in a pretty form.
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* It can handle equations of max two variables (named \em x and \em y ) with
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* no limits on the grade of the terms. (well, the limit is 15, but I doubt
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* anyone will ever use such a factor for a power...)
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// * Use the addTerm() method to add a term to the equation, and removeTerm() to
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// * remove one. After that, use prettyString() to get the equation written in a
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// * If you want to use only the \em x variable, you can unspecify the last
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// * parameters in the term manipulation methods, like addTerm(), term() and
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// * @author Pino Toscano
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* What follows is based on code by Maurizio Paolini
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EquationString( const QString& string );
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double trunc( double );
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void prettify( void );
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void addTerm( double coeff, const QString& unknowns, bool& needsign );
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const QString x3() const;
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const QString y3() const;
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const QString x2y() const;
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const QString xy2() const;
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const QString x2() const;
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const QString y2() const;
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const QString xy() const;
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const QString x() const;
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const QString y() const;
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const QString xnym(int n, int m) const;
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// * Constructs a new empty equation.
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// * Adds a new term to the equation. Use \p xpower and \p ypower to specify
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// * the power of the relative variables. For example, if you would add
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// * \f$-5xy^2 \f$ to the equation, then do:
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// * // other code ...
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// * eq.addTerm( -5, 1, 2 );
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// * \param coeff is the coefficient of the new term
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// * \param xpower is the power of the \em x variable
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// * \param ypower is the power of the \em y variable
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// void addTerm( double coeff, int xpower, int ypower = 0 );
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// * Removes the term with coefficients \p xpower and \p ypower for the
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// * \param xpower is the power of the \em x variable
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// * \param ypower is the power of the \em y variable
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// void removeTerm( int xpower, int ypower = 0 );
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// * Gives the value of the coefficient of the term with coefficients
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// * \p xpower and \p ypower .
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// * \param value will contain the value of the found term, or 0 if not found
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// * \param xpower is the power of the \em x variable
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// * \param ypower is the power of the \em y variable
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// * \return true or false whether the term was found
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// bool term( double& value, int xpower, int ypower = 0 );
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// * Removes all the term of the equation.
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// * Set whether to show a second member for the equation, like \f$... = 0 \f$.
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// * Note that the second member contents can be only a numeric value.
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// * \param show whether to show the second member
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// void setSecondMemberShown( bool show );
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// bool isSecondMemberShown() const;
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// * Sets \p value as the value for the second member. It is displayed only if
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// * you activated it using setShowSecondMember().
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// * The default value for the second member is 0 (zero).
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// void setSecondMemberValue( double value );
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// double secondMemberValue() const;
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// * Returns a string with the current equation written in a nice form.
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// * \param with_spaces specifies whether expand a bit the equation with spaces
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// QString prettyString( bool with_spaces = false ) const;
added
removed
misc/equation.h
