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 — documentation:ref:collectscalars [2015/11/21 12:33] (current) Line 1: Line 1: + ====== CollectScalars ====== + ---- + + ====Description==== + * ''​CollectScalars''​ collects similar scalar factors in products. + ====Examples==== + ---- + Collect same scalars in product: + ​ + println CollectScalars >> '​A_m*A^m*A_n*A^n'​.t + ​ + ​ + > (A_{m}*A^{m})**2 + ​ + + ---- + ''​CollectScalars''​ may significantly simplify expression: + ​ + println CollectScalars >> '​t_mn*f^mn*t_ba*f^ba*R_ij + (t_mn*f^mn)**2*R_ij'​.t​ + ​ + > 2*(t_{mn}*f^{mn})**2*R_{ij} + ​ + + + ---- + ''​CollectScalars''​ takes into account symmetries of tensors: + ​ + setSymmetric '​t_mn'​ + println CollectScalars >> '​t_mn*f^mn*t_ab*f^ba*R_ij'​.t + ​ + ​ + > (t_{mn}*f^{mn})**2*R_{ij} + ​ + + ---- + ''​CollectScalars''​ collects scalars with any complicated structure: + ​ + println CollectScalars >> '(A_i + B_i)*(A^i + B^i)*(A_a + B_a)*(A^a + B^a)'​.t + ​ + ​ + > ((A^{a}+B^{a})*(A_{a}+B_{a}))**2 + ​ + + ---- + + ====See also==== + * Related guides: [[documentation:​guide:​applying_and_manipulating_transformations]],​ [[documentation:​guide:​list_of_transformations]] + * JavaDocs: [[http://​api.redberry.cc/​redberry/​1.1.9/​java-api/​cc/​redberry/​core/​transformations/​CollectScalarFactorsTransformation.html| CollectScalarFactorsTransformation]] + * Source code: [[https://​bitbucket.org/​redberry/​redberry/​src/​tip/​core/​src/​main/​java/​cc/​redberry/​core/​transformations/​CollectScalarFactorsTransformation.java|CollectScalarFactorsTransformation.java]]