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--- user_manual_tomawac [2013/06/06 10:33]
j.parisi
+++ user_manual_tomawac [2014/10/10 16:01] (current)
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 Since the boundary spectrum computation procedures are similar to those for the initial spectrum, refer to
 section 8.4 for further details.
+=== 8.5.3. The LIMWAC user subroutine ===
+It should be reminded that the spectrum is discretised over both frequencies and directions and that it is a
+relative spectrum, i.e. expressed in a coordinate system that moves with the current.
+The subroutine LIMWAC, in its original version, allows to impose the spectrum components at each point of
+a boundary with a prescribed value. The spectrum components are calculated from the parameters specified
+in the CAS file (see section 7.2.1). This subroutine, however, can easily be modified to specify e.g. nonhomogeneous
+(in space) boundary conditions. When such specific boundary conditions are required, these
+will ideally be incorporated in the user part provided in the code of the LIMWAC procedure. The keyword
+BOUNDARY SPECTRUM MODIFIED BY USER must also be set to YES.
+==== 8.6. Some useful subroutines ====
+\\
+=== 8.6.1. Modification of bottom topography: CORFON subroutine ===
+The seabed levels can be modified in two different ways, as already stated in section 7.5.
+The seabed levels can be modifed at the beginning of the computation using the CORFON subroutine, which
+is called once at the beginning of the computation. This subroutine allows the value of the ZF variable to be
+modified at each mesh point. For this purpose, a number of variables such as, for instance, the point
+coordinates, the element area values, the connectivity table, etc., are provided.
+By default, the CORFON subroutine performs the same number of bottom smoothing iterations as LISFON,
+i.e. the same value as specified by the integer keyword BOTTOM SMOOTHINGS.
+Note that the CORFON subroutine is not called in case the computation is initialized with the result of a
+former TOMAWAC run (“hot start”).
+This subroutine is part of the TELEMAC-2D library and is listed in APPENDIX 2.
+=== 8.6.2. Modifying the co-ordinates: CORRXY subroutine ===
+TOMAWAC allows the mesh point co-ordinates to be modified at the beginning of the computation, so that
+an up-scaling (switching from a small scale model to a full-size model), a rotation or a translation can be
+performed.
+Such changes are made using the CORRXY subroutine from the BIEF library, which is called in at the
+beginning of the computation. This subroutine is void by default and provides, in the form of a comment, an example of programming relevant to a change of scale and origin. It is part of the TELEMAC-2D library and
+is listed in APPENDIX 2.
+=== 8.6.3. Operations on vectors: OV subroutine ===
+The BIEF library has a range of very useful subroutines including, in particular, subroutines for operations on
+vectors. A number of relations have been programmed so that loops can be replaced by a mere procedure
+call.
+The syntax is as follows:
+CALL OV(OP, X, Y, Z, C, NPOIN)
+Where OP is a string of exactly 8 digits that is indicative of the operation about to be performed on the X, Y,
+Z vectors and the constant C. The result is the vector X.
+Example:
+  : CALL OV('X=X+Y ', X, Y, Z, C, NPOIN)
+  : Y is added to X, the result will be stored in X.
+A full list of available operations are given in the Guide to programming in the Telemac system version 6.0.