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+ | ====== CollectScalars ====== | ||
+ | ---- | ||
+ | |||
+ | ====Description==== | ||
+ | * ''CollectScalars'' collects similar scalar factors in products. | ||
+ | ====Examples==== | ||
+ | ---- | ||
+ | Collect same scalars in product: | ||
+ | <sxh groovy;gutter:false> | ||
+ | println CollectScalars >> 'A_m*A^m*A_n*A^n'.t | ||
+ | </sxh> | ||
+ | <sxh plain; gutter:false> | ||
+ | > (A_{m}*A^{m})**2 | ||
+ | </sxh> | ||
+ | |||
+ | ---- | ||
+ | ''CollectScalars'' may significantly simplify expression: | ||
+ | <sxh groovy;gutter:false> | ||
+ | println CollectScalars >> 't_mn*f^mn*t_ba*f^ba*R_ij + (t_mn*f^mn)**2*R_ij'.t</sxh> | ||
+ | <sxh plain; gutter:false> | ||
+ | > 2*(t_{mn}*f^{mn})**2*R_{ij} | ||
+ | </sxh> | ||
+ | |||
+ | |||
+ | ---- | ||
+ | ''CollectScalars'' takes into account symmetries of tensors: | ||
+ | <sxh groovy;gutter:false> | ||
+ | setSymmetric 't_mn' | ||
+ | println CollectScalars >> 't_mn*f^mn*t_ab*f^ba*R_ij'.t | ||
+ | </sxh> | ||
+ | <sxh plain; gutter:false> | ||
+ | > (t_{mn}*f^{mn})**2*R_{ij} | ||
+ | </sxh> | ||
+ | |||
+ | ---- | ||
+ | ''CollectScalars'' collects scalars with any complicated structure: | ||
+ | <sxh groovy;gutter:false> | ||
+ | println CollectScalars >> '(A_i + B_i)*(A^i + B^i)*(A_a + B_a)*(A^a + B^a)'.t | ||
+ | </sxh> | ||
+ | <sxh plain; gutter:false> | ||
+ | > ((A^{a}+B^{a})*(A_{a}+B_{a}))**2 | ||
+ | </sxh> | ||
+ | |||
+ | ---- | ||
+ | |||
+ | ====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]] | ||