OtjX,bddlmZddlmZddlmZGddeZGddeZdS) )ExprWithLimits)S)Eqc"eZdZdZfdZxZS) ReorderErrorzC Exception raised when trying to reorder dependent limits. cVt|d|ddS)Nz could not be reordered: .)super__init__)selfexprmsg __class__s `/var/www/html/CA-Chatbot/venv/lib/python3.11/site-packages/sympy/concrete/expr_with_intlimits.pyr zReorderError.__init__ s9 04ccc : < < < < <)__name__ __module__ __qualname____doc__r __classcell__)rs@rrrsB<<<<<<<<>> from sympy import Sum, Product, simplify >>> from sympy.abc import x, y, a, b, c, d, u, v, i, j, k, l >>> S = Sum(x, (x, a, b)) >>> S.doit() -a**2/2 + a/2 + b**2/2 + b/2 >>> Sn = S.change_index(x, x + 1, y) >>> Sn Sum(y - 1, (y, a + 1, b + 1)) >>> Sn.doit() -a**2/2 + a/2 + b**2/2 + b/2 >>> Sn = S.change_index(x, -x, y) >>> Sn Sum(-y, (y, -b, -a)) >>> Sn.doit() -a**2/2 + a/2 + b**2/2 + b/2 >>> Sn = S.change_index(x, x+u) >>> Sn Sum(-u + x, (x, a + u, b + u)) >>> Sn.doit() -a**2/2 - a*u + a/2 + b**2/2 + b*u + b/2 - u*(-a + b + 1) + u >>> simplify(Sn.doit()) -a**2/2 + a/2 + b**2/2 + b/2 >>> Sn = S.change_index(x, -x - u, y) >>> Sn Sum(-u - y, (y, -b - u, -a - u)) >>> Sn.doit() -a**2/2 - a*u + a/2 + b**2/2 + b*u + b/2 - u*(-a + b + 1) + u >>> simplify(Sn.doit()) -a**2/2 + a/2 + b**2/2 + b/2 >>> P = Product(i*j**2, (i, a, b), (j, c, d)) >>> P Product(i*j**2, (i, a, b), (j, c, d)) >>> P2 = P.change_index(i, i+3, k) >>> P2 Product(j**2*(k - 3), (k, a + 3, b + 3), (j, c, d)) >>> P3 = P2.change_index(j, -j, l) >>> P3 Product(l**2*(k - 3), (k, a + 3, b + 3), (l, -d, -c)) When dealing with symbols only, we can make a general linear transformation: >>> Sn = S.change_index(x, u*x+v, y) >>> Sn Sum((-v + y)/u, (y, b*u + v, a*u + v)) >>> Sn.doit() -v*(a*u - b*u + 1)/u + (a**2*u**2/2 + a*u*v + a*u/2 - b**2*u**2/2 - b*u*v + b*u/2 + v)/u >>> simplify(Sn.doit()) a**2*u/2 + a/2 - b**2*u/2 + b/2 However, the last result can be inconsistent with usual summation where the index increment is always 1. This is obvious as we get back the original value only for ``u`` equal +1 or -1. See Also ======== sympy.concrete.expr_with_intlimits.ExprWithIntLimits.index, reorder_limit, sympy.concrete.expr_with_intlimits.ExprWithIntLimits.reorder, sympy.concrete.summations.Sum.reverse_order, sympy.concrete.products.Product.reverse_order Nrz"Index transformation is not linearz>Linear transformation results in non-linear summation stepsize) limitsas_polydegree ValueErrorcoeff_monomialrOne is_numberappend NegativeOnefunctionsubsfunc) r vartrafonewvarrlimitpalphabetar&s r change_indexzExprWithIntLimits.change_indexsr >F[ % %EQx3MM#&&88::??$%IJJJ((--''..? Z~~ vuU1X~/DeERSHnW[F[&\]]]]!-// vuU1X~/DeERSHnW[F[&\]]]]()ijjjMM65q>D+@%a.SWBW"XYYYY e$$$$=%%cC$J+=>>==f--ty+F++++rcd|jD}||dkrt|d||S)aX Return the index of a dummy variable in the list of limits. Explanation =========== ``index(expr, x)`` returns the index of the dummy variable ``x`` in the limits of ``expr``. Note that we start counting with 0 at the inner-most limits tuple. Examples ======== >>> from sympy.abc import x, y, a, b, c, d >>> from sympy import Sum, Product >>> Sum(x*y, (x, a, b), (y, c, d)).index(x) 0 >>> Sum(x*y, (x, a, b), (y, c, d)).index(y) 1 >>> Product(x*y, (x, a, b), (y, c, d)).index(x) 0 >>> Product(x*y, (x, a, b), (y, c, d)).index(y) 1 See Also ======== reorder_limit, reorder, sympy.concrete.summations.Sum.reverse_order, sympy.concrete.products.Product.reverse_order cg|] }|d Srr.0r,s r z+ExprWithIntLimits.index..s777%U1X777rrz0Number of instances of variable not equal to one)rcountr index)r x variabless rr8zExprWithIntLimits.indexsS>874;777 ??1   " "T#UVV V??1%% %rc~|}|D]}t|dkrt|d|d}|d}t|dts||d}t|dts||d}|||}|S)a Reorder limits in a expression containing a Sum or a Product. Explanation =========== ``expr.reorder(*arg)`` reorders the limits in the expression ``expr`` according to the list of tuples given by ``arg``. These tuples can contain numerical indices or index variable names or involve both. Examples ======== >>> from sympy import Sum, Product >>> from sympy.abc import x, y, z, a, b, c, d, e, f >>> Sum(x*y, (x, a, b), (y, c, d)).reorder((x, y)) Sum(x*y, (y, c, d), (x, a, b)) >>> Sum(x*y*z, (x, a, b), (y, c, d), (z, e, f)).reorder((x, y), (x, z), (y, z)) Sum(x*y*z, (z, e, f), (y, c, d), (x, a, b)) >>> P = Product(x*y*z, (x, a, b), (y, c, d), (z, e, f)) >>> P.reorder((x, y), (x, z), (y, z)) Product(x*y*z, (z, e, f), (y, c, d), (x, a, b)) We can also select the index variables by counting them, starting with the inner-most one: >>> Sum(x**2, (x, a, b), (x, c, d)).reorder((0, 1)) Sum(x**2, (x, c, d), (x, a, b)) And of course we can mix both schemes: >>> Sum(x*y, (x, a, b), (y, c, d)).reorder((y, x)) Sum(x*y, (y, c, d), (x, a, b)) >>> Sum(x*y, (x, a, b), (y, c, d)).reorder((y, 0)) Sum(x*y, (y, c, d), (x, a, b)) See Also ======== reorder_limit, index, sympy.concrete.summations.Sum.reverse_order, sympy.concrete.products.Product.reverse_order rzInvalid number of argumentsrr)lenr isinstanceintr8 reorder_limit)r argnew_exprrindex1index2s rreorderzExprWithIntLimits.reorders\ > >A1vv{{ $ABBBqTFqTFadC(( *AaD))adC(( *AaD))--ff==HHrctd|jD}|j|}|j|}tt|dj|dkr?tt|dj|dkrtt|dj|dkrtt|dj|dkrg}t |jD]R\}}||kr||!||kr||=||St||jg|RSt|d)a- Interchange two limit tuples of a Sum or Product expression. Explanation =========== ``expr.reorder_limit(x, y)`` interchanges two limit tuples. The arguments ``x`` and ``y`` are integers corresponding to the index variables of the two limits which are to be interchanged. The expression ``expr`` has to be either a Sum or a Product. Examples ======== >>> from sympy.abc import x, y, z, a, b, c, d, e, f >>> from sympy import Sum, Product >>> Sum(x*y*z, (x, a, b), (y, c, d), (z, e, f)).reorder_limit(0, 2) Sum(x*y*z, (z, e, f), (y, c, d), (x, a, b)) >>> Sum(x**2, (x, a, b), (x, c, d)).reorder_limit(1, 0) Sum(x**2, (x, c, d), (x, a, b)) >>> Product(x*y*z, (x, a, b), (y, c, d), (z, e, f)).reorder_limit(0, 2) Product(x*y*z, (z, e, f), (y, c, d), (x, a, b)) See Also ======== index, reorder, sympy.concrete.summations.Sum.reverse_order, sympy.concrete.products.Product.reverse_order ch|] }|d Sr3rr4s r z2ExprWithIntLimits.reorder_limit..s111EuQx111rrrrz.could not interchange the two limits specified) rr<set free_symbols intersection enumerater$typer&r) r r9yr)limit_xlimit_yrir,s rr?zExprWithIntLimits.reorder_limits@21T[111+a.+a. GAJ+,,99#>> ? ?1 D D GAJ+,,99#>> ? ?1 D D GAJ+,,99#>> ? ?1 D D GAJ+,,99#>> ? ?1 D DF%dk22 ) )566MM'****!VVMM'****MM%((((4::dm5f555 5t%UVV Vrcd}|jD]5}|d|dz }t|d}|dkrdS|dkr3d}6|rdSdS)a Returns True if the Sum or Product is computed for an empty sequence. Examples ======== >>> from sympy import Sum, Product, Symbol >>> m = Symbol('m') >>> Sum(m, (m, 1, 0)).has_empty_sequence True >>> Sum(m, (m, 1, 1)).has_empty_sequence False >>> M = Symbol('M', integer=True, positive=True) >>> Product(m, (m, 1, M)).has_empty_sequence False >>> Product(m, (m, 2, M)).has_empty_sequence >>> Product(m, (m, M + 1, M)).has_empty_sequence True >>> N = Symbol('N', integer=True, positive=True) >>> Sum(m, (m, N, M)).has_empty_sequence >>> N = Symbol('N', integer=True, negative=True) >>> Sum(m, (m, N, M)).has_empty_sequence False See Also ======== has_reversed_limits has_finite_limits FrrTN)rr)r ret_Nonelimdifeqs rhas_empty_sequencez$ExprWithIntLimits.has_empty_sequence.snN;  Ca&3q6/CCBTzzttu  4ur)N) rrrr __slots__r0r8rEr?propertyrWrrrrr s  It,t,t,t,n$&$&$&L>>>B4W4W4Wl33X333rrN) sympy.concrete.expr_with_limitsrsympy.core.singletonrsympy.core.relationalrNotImplementedErrorrrrrrr^s::::::""""""$$$$$$<<<<<&<<<UUUUUUUUUUr