Changes between Version 197 and Version 198 of doc/app/runtime_parameters

Timestamp:

Oct 20, 2010 1:32:13 PM (15 years ago)

Author:

gryschka

Comment:

--

doc/app/runtime_parameters

@@ -3 +3 @@
 ==== [#output Data output] ====
 ==== [#run Run steering] ====
+==== [#grid Grid ] ====
 \\\\\\\\\\\\\\\\\\\\\\\\\\
 [=#output '''Data output:]\\
@@ -1445 +1446 @@
 For [../examples/coupled coupled runs] this parameter must be equal in both parameter files [[../iofiles#PARIN|PARIN]] and [[../iofiles#PARIN_O|PARIN_O]].
 }}}
+\\\\
+[=#grid '''grid:]\\
+||='''Parameter Name'''  =||='''[[../fortrantypes|FORTRAN]]\\[[../fortrantypes|Type]]'''  =||='''Default\\Value'''  =||='''Explanation'''  =||
+|----------------
+{{{#!td style="vertical-align:top"
+[=#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].
+}}}