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4    	/*         SCIP --- Solving Constraint Integer Programs                      */
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24   	
25   	/**@file   cons_quadratic.c
26   	 * @ingroup DEFPLUGINS_CONS
27   	 * @brief  some API functions of removed constraint handler for quadratic constraints \f$\textrm{lhs} \leq \sum_{i,j} a_{i,j} x_i x_j + \sum_i b_i x_i \leq \textrm{rhs}\f$
28   	 * @author Stefan Vigerske
29   	 */
30   	
31   	/*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
32   	
33   	#include "scip/cons_nonlinear.h"
34   	#include "scip/cons_quadratic.h"
35   	#include "scip/expr_var.h"
36   	#include "scip/expr_pow.h"
37   	#include "scip/expr_product.h"
38   	
39   	/** Creates and captures a quadratic nonlinear constraint.
40   	 *
41   	 *  The constraint should be given in the form
42   	 *  \f[
43   	 *  \ell \leq \sum_{i=1}^n b_i x_i + \sum_{j=1}^m a_j y_j z_j \leq u,
44   	 *  \f]
45   	 *  where \f$x_i = y_j = z_k\f$ is possible.
46   	 *
47   	 *  @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()
48   	 *
49   	 *  @deprecated Use SCIPcreateConsQuadraticNonlinear() instead.
50   	 */
51   	SCIP_RETCODE SCIPcreateConsQuadratic(
52   	   SCIP*                 scip,               /**< SCIP data structure */
53   	   SCIP_CONS**           cons,               /**< pointer to hold the created constraint */
54   	   const char*           name,               /**< name of constraint */
55   	   int                   nlinvars,           /**< number of linear terms (n) */
56   	   SCIP_VAR**            linvars,            /**< variables in linear part (x_i) or NULL if nlinvars == 0 */
57   	   SCIP_Real*            lincoefs,           /**< coefficients of variables in linear part (b_i) or NULL if nlinvars == 0 */
58   	   int                   nquadterms,         /**< number of quadratic terms (m) */
59   	   SCIP_VAR**            quadvars1,          /**< array with first variables in quadratic terms (y_j) or NULL if nquadterms == 0 */
60   	   SCIP_VAR**            quadvars2,          /**< array with second variables in quadratic terms (z_j) or NULL if nquadterms == 0 */
61   	   SCIP_Real*            quadcoeffs,         /**< array with coefficients of quadratic terms (a_j) or NULL if nquadterms == 0 */
62   	   SCIP_Real             lhs,                /**< left hand side of quadratic equation (l) */
63   	   SCIP_Real             rhs,                /**< right hand side of quadratic equation (u) */
64   	   SCIP_Bool             initial,            /**< should the LP relaxation of constraint be in the initial LP?
65   	                                              *   Usually set to TRUE. Set to FALSE for 'lazy constraints'. */
66   	   SCIP_Bool             separate,           /**< should the constraint be separated during LP processing?
67   	                                              *   Usually set to TRUE. */
68   	   SCIP_Bool             enforce,            /**< should the constraint be enforced during node processing?
69   	                                              *   TRUE for model constraints, FALSE for additional, redundant constraints. */
70   	   SCIP_Bool             check,              /**< should the constraint be checked for feasibility?
71   	                                              *   TRUE for model constraints, FALSE for additional, redundant constraints. */
72   	   SCIP_Bool             propagate,          /**< should the constraint be propagated during node processing?
73   	                                              *   Usually set to TRUE. */
74   	   SCIP_Bool             local,              /**< is constraint only valid locally?
75   	                                              *   Usually set to FALSE. Has to be set to TRUE, e.g., for branching constraints. */
76   	   SCIP_Bool             modifiable,         /**< is constraint modifiable (subject to column generation)?
77   	                                              *   Usually set to FALSE. In column generation applications, set to TRUE if pricing
78   	                                              *   adds coefficients to this constraint. */
79   	   SCIP_Bool             dynamic,            /**< is constraint subject to aging?
80   	                                              *   Usually set to FALSE. Set to TRUE for own cuts which
81   	                                              *   are separated as constraints. */
82   	   SCIP_Bool             removable           /**< should the relaxation be removed from the LP due to aging or cleanup?
83   	                                              *   Usually set to FALSE. Set to TRUE for 'lazy constraints' and 'user cuts'. */
84   	   )
85   	{
86   	   SCIP_CALL( SCIPcreateConsQuadraticNonlinear(scip, cons, name, nlinvars, linvars, lincoefs, nquadterms, quadvars1, quadvars2, quadcoeffs, lhs, rhs,
87   	      initial, separate, enforce, check, propagate, local, modifiable, dynamic, removable) );
88   	
89   	   return SCIP_OKAY;
90   	}
91   	
92   	/** creates and captures a quadratic nonlinear constraint
93   	 *  in its most basic variant, i.e., with all constraint flags set to their default values, which can be set
94   	 *  afterwards using SCIPsetConsFLAGNAME()
95   	 *
96   	 *  The constraint should be given in the form
97   	 *  \f[
98   	 *  \ell \leq \sum_{i=1}^n b_i x_i + \sum_{j=1}^m a_j y_jz_j \leq u,
99   	 *  \f]
100  	 *  where \f$x_i = y_j = z_k\f$ is possible.
101  	 *
102  	 *  @see SCIPcreateConsQuadratic() for the default constraint flag configuration
103  	 *
104  	 *  @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()
105  	 *
106  	 *  @deprecated Use SCIPcreateConsBasicQuadraticNonlinear instead.
107  	 */
108  	SCIP_RETCODE SCIPcreateConsBasicQuadratic(
109  	   SCIP*                 scip,               /**< SCIP data structure */
110  	   SCIP_CONS**           cons,               /**< pointer to hold the created constraint */
111  	   const char*           name,               /**< name of constraint */
112  	   int                   nlinvars,           /**< number of linear terms (n) */
113  	   SCIP_VAR**            linvars,            /**< array with variables in linear part (x_i) */
114  	   SCIP_Real*            lincoefs,           /**< array with coefficients of variables in linear part (b_i) */
115  	   int                   nquadterms,         /**< number of quadratic terms (m) */
116  	   SCIP_VAR**            quadvars1,          /**< array with first variables in quadratic terms (y_j) */
117  	   SCIP_VAR**            quadvars2,          /**< array with second variables in quadratic terms (z_j) */
118  	   SCIP_Real*            quadcoefs,          /**< array with coefficients of quadratic terms (a_j) */
119  	   SCIP_Real             lhs,                /**< left hand side of quadratic equation (ell) */
120  	   SCIP_Real             rhs                 /**< right hand side of quadratic equation (u) */
121  	   )
122  	{
123  	   SCIP_CALL( SCIPcreateConsBasicQuadraticNonlinear(scip, cons, name, nlinvars, linvars, lincoefs, nquadterms, quadvars1, quadvars2, quadcoefs, lhs, rhs) );
124  	
125  	   return SCIP_OKAY;
126  	}
127  	
128  	/** Adds a constant to the constraint function, that is, subtracts a constant from both sides
129  	 *
130  	 * @deprecated Use SCIPchgLhsNonlinear() and SCIPchgRhsNonlinear() instead.
131  	 */
132  	void SCIPaddConstantQuadratic(
133  	   SCIP*                 scip,               /**< SCIP data structure */
134  	   SCIP_CONS*            cons,               /**< constraint */
135  	   SCIP_Real             constant            /**< constant to subtract from both sides */
136  	   )
137  	{
138  	   SCIP_Real side;
139  	
140  	   assert(cons != NULL);
141  	   assert(strcmp(SCIPconshdlrGetName(SCIPconsGetHdlr(cons)), "nonlinear") == 0);
142  	
143  	   side = SCIPgetLhsNonlinear(cons);
144  	   if( !SCIPisInfinity(scip, -side) )
145  	   {
146  	      SCIP_CALL_ABORT( SCIPchgLhsNonlinear(scip, cons, side-constant) );
147  	   }
148  	
149  	   side = SCIPgetRhsNonlinear(cons);
150  	   if( !SCIPisInfinity(scip, side) )
151  	   {
152  	      SCIP_CALL_ABORT( SCIPchgRhsNonlinear(scip, cons, side-constant) );
153  	   }
154  	}
155  	
156  	/** Adds a linear variable with coefficient to a quadratic constraint.
157  	 *
158  	 * @deprecated Use SCIPaddLinearVarNonlinear() instead.
159  	 */
160  	SCIP_RETCODE SCIPaddLinearVarQuadratic(
161  	   SCIP*                 scip,               /**< SCIP data structure */
162  	   SCIP_CONS*            cons,               /**< constraint */
163  	   SCIP_VAR*             var,                /**< variable */
164  	   SCIP_Real             coef                /**< coefficient of variable */
165  	   )
166  	{
167  	   assert(cons != NULL);
168  	   assert(strcmp(SCIPconshdlrGetName(SCIPconsGetHdlr(cons)), "nonlinear") == 0);
169  	
170  	   SCIP_CALL( SCIPaddLinearVarNonlinear(scip, cons, var, coef) );
171  	
172  	   return SCIP_OKAY;
173  	}
174  	
175  	/** Adds a quadratic variable with linear and square coefficient to a quadratic constraint.
176  	 *
177  	 * @deprecated Use SCIPaddLinearVarNonlinear() and SCIPaddExprNonlinear() instead.
178  	 */
179  	SCIP_RETCODE SCIPaddQuadVarQuadratic(
180  	   SCIP*                 scip,               /**< SCIP data structure */
181  	   SCIP_CONS*            cons,               /**< constraint */
182  	   SCIP_VAR*             var,                /**< variable */
183  	   SCIP_Real             lincoef,            /**< linear coefficient of variable */
184  	   SCIP_Real             sqrcoef             /**< square coefficient of variable */
185  	   )
186  	{
187  	   assert(cons != NULL);
188  	   assert(strcmp(SCIPconshdlrGetName(SCIPconsGetHdlr(cons)), "nonlinear") == 0);
189  	
190  	   if( lincoef != 0.0 )
191  	   {
192  	      SCIP_CALL( SCIPaddLinearVarNonlinear(scip, cons, var, lincoef) );
193  	   }
194  	
195  	   if( sqrcoef != 0.0 )
196  	   {
197  	      SCIP_EXPR* varexpr;
198  	      SCIP_EXPR* sqrexpr;
199  	
200  	      SCIP_CALL( SCIPcreateExprVar(scip, &varexpr, var, NULL, NULL) );
201  	      SCIP_CALL( SCIPcreateExprPow(scip, &sqrexpr, varexpr, 2.0, NULL, NULL) );
202  	
203  	      SCIP_CALL( SCIPaddExprNonlinear(scip, cons, sqrexpr, sqrcoef) );
204  	
205  	      SCIP_CALL( SCIPreleaseExpr(scip, &sqrexpr) );
206  	      SCIP_CALL( SCIPreleaseExpr(scip, &varexpr) );
207  	   }
208  	
209  	   return SCIP_OKAY;
210  	}
211  	
212  	/** Adds a linear coefficient for a quadratic variable.
213  	 *
214  	 * Variable will be added with square coefficient 0.0 if not existing yet.
215  	 *
216  	 * @deprecated Use SCIPaddLinearVarNonlinear() instead.
217  	 */
218  	SCIP_RETCODE SCIPaddQuadVarLinearCoefQuadratic(
219  	   SCIP*                 scip,               /**< SCIP data structure */
220  	   SCIP_CONS*            cons,               /**< constraint */
221  	   SCIP_VAR*             var,                /**< variable */
222  	   SCIP_Real             coef                /**< value to add to linear coefficient of variable */
223  	   )
224  	{
225  	   assert(cons != NULL);
226  	   assert(strcmp(SCIPconshdlrGetName(SCIPconsGetHdlr(cons)), "nonlinear") == 0);
227  	
228  	   SCIP_CALL( SCIPaddLinearVarNonlinear(scip, cons, var, coef) );
229  	
230  	   return SCIP_OKAY;
231  	}
232  	
233  	/** Adds a square coefficient for a quadratic variable.
234  	 *
235  	 * Variable will be added with linear coefficient 0.0 if not existing yet.
236  	 *
237  	 * @deprecated Use SCIPaddExprNonlinear() instead.
238  	 */
239  	SCIP_RETCODE SCIPaddSquareCoefQuadratic(
240  	   SCIP*                 scip,               /**< SCIP data structure */
241  	   SCIP_CONS*            cons,               /**< constraint */
242  	   SCIP_VAR*             var,                /**< variable */
243  	   SCIP_Real             coef                /**< value to add to square coefficient of variable */
244  	   )
245  	{
246  	   SCIP_EXPR* varexpr;
247  	   SCIP_EXPR* sqrexpr;
248  	
249  	   assert(cons != NULL);
250  	   assert(strcmp(SCIPconshdlrGetName(SCIPconsGetHdlr(cons)), "nonlinear") == 0);
251  	
252  	   SCIP_CALL( SCIPcreateExprVar(scip, &varexpr, var, NULL, NULL) );
253  	   SCIP_CALL( SCIPcreateExprPow(scip, &sqrexpr, varexpr, 2.0, NULL, NULL) );
254  	
255  	   SCIP_CALL( SCIPaddExprNonlinear(scip, cons, sqrexpr, coef) );
256  	
257  	   SCIP_CALL( SCIPreleaseExpr(scip, &sqrexpr) );
258  	   SCIP_CALL( SCIPreleaseExpr(scip, &varexpr) );
259  	
260  	   return SCIP_OKAY;
261  	}
262  	
263  	/** Adds a bilinear term to a quadratic constraint.
264  	 *
265  	 * Variables will be added with linear and square coefficient 0.0 if not existing yet.
266  	 * If variables are equal, only the square coefficient of the variable is updated.
267  	 *
268  	 * @deprecated Use SCIPaddExprNonlinear() instead.
269  	 */
270  	SCIP_RETCODE SCIPaddBilinTermQuadratic(
271  	   SCIP*                 scip,               /**< SCIP data structure */
272  	   SCIP_CONS*            cons,               /**< constraint */
273  	   SCIP_VAR*             var1,               /**< first variable */
274  	   SCIP_VAR*             var2,               /**< second variable */
275  	   SCIP_Real             coef                /**< coefficient of bilinear term */
276  	   )
277  	{
278  	   SCIP_EXPR* varexprs[2];
279  	   SCIP_EXPR* prodexpr;
280  	
281  	   assert(cons != NULL);
282  	   assert(strcmp(SCIPconshdlrGetName(SCIPconsGetHdlr(cons)), "nonlinear") == 0);
283  	
284  	   SCIP_CALL( SCIPcreateExprVar(scip, &varexprs[0], var1, NULL, NULL) );
285  	   SCIP_CALL( SCIPcreateExprVar(scip, &varexprs[1], var2, NULL, NULL) );
286  	   SCIP_CALL( SCIPcreateExprProduct(scip, &prodexpr, 2, varexprs, 1.0, NULL, NULL) );
287  	
288  	   SCIP_CALL( SCIPaddExprNonlinear(scip, cons, prodexpr, coef) );
289  	
290  	   SCIP_CALL( SCIPreleaseExpr(scip, &prodexpr) );
291  	   SCIP_CALL( SCIPreleaseExpr(scip, &varexprs[1]) );
292  	   SCIP_CALL( SCIPreleaseExpr(scip, &varexprs[0]) );
293  	
294  	   return SCIP_OKAY;
295  	}
296  	
297  	/** Gets the quadratic constraint as a nonlinear row representation.
298  	 *
299  	 * @deprecated Use SCIPgetNlRowNonlinear() instead.
300  	 */
301  	SCIP_RETCODE SCIPgetNlRowQuadratic(
302  	   SCIP*                 scip,               /**< SCIP data structure */
303  	   SCIP_CONS*            cons,               /**< constraint */
304  	   SCIP_NLROW**          nlrow               /**< pointer to store nonlinear row */
305  	   )
306  	{
307  	   assert(cons != NULL);
308  	   assert(strcmp(SCIPconshdlrGetName(SCIPconsGetHdlr(cons)), "nonlinear") == 0);
309  	
310  	   SCIP_CALL( SCIPgetNlRowNonlinear(scip, cons, nlrow) );
311  	
312  	   return SCIP_OKAY;
313  	}
314  	
315  	/** sets the left hand side of a quadratic constraint
316  	 *
317  	 *  @note This method may only be called during problem creation stage for an original constraint.
318  	 *
319  	 *  @deprecated Use SCIPchgLhsNonlinear() instead.
320  	 */
321  	SCIP_RETCODE SCIPchgLhsQuadratic(
322  	   SCIP*                 scip,               /**< SCIP data structure */
323  	   SCIP_CONS*            cons,               /**< constraint data */
324  	   SCIP_Real             lhs                 /**< new left hand side */
325  	   )
326  	{
327  	   assert(cons != NULL);
328  	   assert(strcmp(SCIPconshdlrGetName(SCIPconsGetHdlr(cons)), "nonlinear") == 0);
329  	
330  	   SCIP_CALL( SCIPchgLhsNonlinear(scip, cons, lhs) );
331  	
332  	   return SCIP_OKAY;
333  	}
334  	
335  	/** sets the right hand side of a quadratic constraint
336  	 *
337  	 *  @note This method may only be called during problem creation stage for an original constraint.
338  	 *
339  	 *  @deprecated Use SCIPchgRhsNonlinear() instead.
340  	 */
341  	SCIP_RETCODE SCIPchgRhsQuadratic(
342  	   SCIP*                 scip,               /**< SCIP data structure */
343  	   SCIP_CONS*            cons,               /**< constraint data */
344  	   SCIP_Real             rhs                 /**< new right hand side */
345  	   )
346  	{
347  	   assert(cons != NULL);
348  	   assert(strcmp(SCIPconshdlrGetName(SCIPconsGetHdlr(cons)), "nonlinear") == 0);
349  	
350  	   SCIP_CALL( SCIPchgRhsNonlinear(scip, cons, rhs) );
351  	
352  	   return SCIP_OKAY;
353  	}
354