Changes between Version 73 and Version 74 of doc/app/initialization_parameters

Timestamp:

Sep 14, 2010 3:40:10 PM (14 years ago)

Author:

kanani

Comment:

--

doc/app/initialization_parameters

@@ -428 +428 @@
 |----------------
 {{{#!td style="vertical-align:top"
-[=#<insert_parameter_name> '''<insert_parameter_name>''']
-}}}
-{{{#!td style="vertical-align:top"
-<insert type>
-}}}
-{{{#!td style="vertical-align:top"
-<insert value>
-}}}
-{{{#!td
-<insert explanation>
-}}}
-|----------------
-{{{#!td style="vertical-align:top"
-[=#<insert_parameter_name> '''<insert_parameter_name>''']
-}}}
-{{{#!td style="vertical-align:top"
-<insert type>
-}}}
-{{{#!td style="vertical-align:top"
-<insert value>
-}}}
-{{{#!td
-<insert explanation>
+[=#npex '''npex''']
+}}}
+{{{#!td style="vertical-align:top"
+I
+}}}
+{{{#!td style="vertical-align:top"
+
+}}}
+{{{#!td
+Number of processors along x-direction of the virtual processor net.\\\\
+For parallel runs, the total number of processors to be used is given by the '''mrun'''-option -X. By default, depending on the type of the parallel computer, PALM generates a 1d processor net (domain decomposition along x, [#npey npey] = ''1'') or a 2d-net (this is favored on machines with fast communication network and/or large number of processors (>256)). In case of a 2d-net, it is tried to make it more or less square-shaped. If, for example, 16 processors are assigned (-X 16), a 4 * 4 processor net is generated ('''npex''' = 4, '''npey''' = 4). This choice is optimal for square total domains ([#nx nx] = [#ny ny]), since then the number of ghost points at the lateral boundarys of the subdomains reaches a minimum. If nx and ny differ extremely, the processor net should be manually adjusted using adequate values for '''npex''' and '''npey'''.\\\\
+'''Important:'''\\\\
+The value of '''npex''' * '''npey''' must exactly match the value assigned by the '''mrun'''-option -X. Otherwise the model run will abort with a corresponding error message.\\\\ 
+Additionally, the specification of '''npex''' and '''npey''' may of course override the default setting for the domain decomposition (1d or 2d) which may have a significant (negative) effect on the code performance. 
+}}}
+|----------------
+{{{#!td style="vertical-align:top"
+[=#npey '''npey''']
+}}}
+{{{#!td style="vertical-align:top"
+I
+}}}
+{{{#!td style="vertical-align:top"
+
+}}}
+{{{#!td
+Number of processors along y-direction of the virtual processor net.\\\\
+For further information see [#npex npex].
 }}}
 |----------------
@@ -622 +627 @@
 |----------------
 {{{#!td style="vertical-align:top"
-[=#<insert_parameter_name> '''<insert_parameter_name>''']
-}}}
-{{{#!td style="vertical-align:top"
-<insert type>
-}}}
-{{{#!td style="vertical-align:top"
-<insert value>
-}}}
-{{{#!td
-<insert explanation>
+[=#ngsrb '''ngsrb''']
+}}}
+{{{#!td style="vertical-align:top"
+I
+}}}
+{{{#!td style="vertical-align:top"
+2
+}}}
+{{{#!td
+Grid level at which data shall be gathered on PE0.\\\\
+In case of a run using several PEs and the multigrid method for solving the Poisson equation for perturbation pressure (see [#psolver psolver]), the value of this parameter defines on which grid level the data are gathered on PE0 in order to allow for a further coarsening of the grid. The finest grid defines the largest grid level. By default, the gathering level is determined automatically and displayed in file [../iofiles#RUN_CONTROL RUN_CONTROL]. It is only possible to gather data from a level larger than the one determined automatically. A test run may be neccessary to determine this level.
 }}}
 |----------------