Go to the first, previous, next, last section, table of contents.

POSTPROCESS DATA FILES

In the GiD postprocess you can study the results obtained from a solver program. The communication between the solver and the GiD Postprocess is made using files. The solver program has to write the results in a file that must have the extension .post.res, or the old .flavia.res, and its name must be the project name.

The solver program can also (it is not mandatory) give to GiD the postprocess mesh, and should have the extension .post.msh, or the old .flavia.msh. If this mesh is not provided by the solver program, GiD uses in the post-process, the preprocess mesh.

The extensions .msh and .res are also allowed, but only the files with the extensions .post.res, or the old .flavia.res, and eventually .post.msh, or the old .flavia.msh, will be automatically read by GiD when postprocessing the GiD project.

So, post-processing data files are ASCII files, and can be separated into two categories:



Note: ProjectName.post.msh, or the old ProjectName.flavia.msh, handles meshes of different element types: points, lines, triangles, quadrilaterals, tetrahedras and hexahedras. The old format, which only handles one type of element per file, is still supported inside GiD (see section Old postprocess mesh format).

If a project is loaded into GiD, when changing to PostProcess it will look for ProjectName.post.res, or the old ProjectName.flavia.res. If a mesh information file with name ProjectName.post.msh, or the old ProjectName.flavia.msh is present, it will also be read, regardless of the information available from PreProcess.

The files are created and read in the order that corresponds with the natural way of solving a finite element problem: mesh, surface definition and conditions and finally, evaluation of the results. The format of the read statements is normally free, i.e. it is necessary only to separate them by spaces.

Thus, the users can modify the files with any format, leaving spaces between each field and can also write out the results with as many decimals as desired. In case of error, the program warns the user about the type of mistake found.

GiD reads all the information directly from the pre-processing files in order to gain efficiency, whenever possible.



Postprocess mesh format: ProjectName.post.msh, ProjectName.flavia.msh

Note: This postprocess mesh format needs GiD version 6.0 or higher.

Comments are allowed and should begin with a '#'. Blank lines are also allowed.

To enter the mesh names and result names in another encoding, just write # encoding your_encoding for example:

# encoding utf-8

Inside this file one or more MESHes can be defined, each of them should:



Mesh example

This example clarifies this description: 


#mesh of a table
MESH "board" dimension 3 ElemType Triangle  Nnode 3
# color 127 127 0
Coordinates
# node number   coordinate_x  coordinate_y  coordinate_z
    1             -5              3             -3
    2             -5              3              0
    3             -5              0              0
    4             -2              2              0
    5       -1.66667              3              0
    6             -5             -3             -3
    7             -2             -2              0
    8              0              0              0
    9             -5             -3              0
   10        1.66667              3              0
   11       -1.66667             -3              0
   12              2              2              0
   13              2             -2              0
   14        1.66667             -3              0
   15              5              3             -3
   16              5              3              0
   17              5              0              0
   18              5             -3             -3
   19              5             -3              0
end coordinates

#we put both material in the same MESH, 
#but they could be separated into two MESH

Elements
# element  node_1   node_2  node_3 material_number
    5         19      17      13     3
    6          3       9       7     3
    7          2       3       4     3
    8         17      16      12     3
    9         12      16      10     3
   10         12      10       4     3
   11          7       9      11     3
   12          7      11      13     3
   13          2       4       5     3
   14          5       4      10     3
   15         19      13      14     3
   16         14      13      11     3
   17          3       7       4     3
   18         17      12      13     3
   19         13      12       8     4
   20         13       8       7     4
   21          7       8       4     4
   22          4       8      12     4
end elements

MESH    dimension 3 ElemType Linear  Nnode 2
Coordinates
#no coordinates then they are already in the first MESH
end coordinates

Elements
# element  node_1   node_2 material_number
    1          9       6     5
    2         19      18     5
    3         16      15     5
    4          2       1     5
end elements



Postprocess results format: ProjectName.post.res, ProjectName.flavia.res

Note: The new postprocess results format needs GiD version 6.1.4b or higher.

Note: The code developers can download, from the GiD web page, the GiDpost tool, a C/C++/Fortran library to create postprocess files for GiD, in ASCII or compressed binary format.

This is the ASCII format description:

The first line of the files with results written in this new postprocess format should be:

GiD Post Results File 1.0

Comment lines are allowed and should begin with a '#'. Blank lines are also allowed.

Results files can also be included with the keyword include, for instance:

include "My Other Results File"

This is useful, for instance, to share several GaussPoints definitions and ResultRangeTable among different analysis.

This 'include' should be outside the Blocks of information.

There are several types of Blocks of information, all of them identified by a keyword:



Gauss Points

To include Gauss points they must be defined before the Result which uses them.

Each Gauss points block are defined between a pair of GaussPoints and End GaussPoints.

The structure is as follows:

Here comes an example of results on Gauss Points: 

GaussPoints "Board gauss internal" ElemType Triangle "board"
  Number Of Gauss Points: 3
  Natural Coordinates: internal
end gausspoints



Result Range Table

To include a Result Range Table it must be defined before the Result which uses it.

Each Result Range Table is defined between a pair of ResultRangesTable and End ResultRangesTable.

The structure is as follows:

Several examples of results ranges table follows,



Result block

Each Result block is identified by a Result header, followed by several optional properties: component names, ranges table, and the result values, defined the pair of Values and End Values.

The structure is as follows:

Note: for Matrix and PlainDeformationMatrix results, the Si, Sii and Siii components are calculated by GiD, which represents the eigen values & vectors of the matrix results, and which are ordered according to the eigen value.



Result group

Results canbe grouped into on block. These results belongs to the same time step of the same analysis and are located in the same place. So all the results in the group are nodal results or are defined over the same gauss points set.

Each Result group is identified by a ResultGroup header, followed by the results descriptions and its optional properties, such as components names and ranges tables, and the results values, between the pair Values ... End values.

The structure is as follows:

Note: Vectors in a ResultGroup have always three components.

Note: Matrix in a ResultGroup have always six components.

Note: all the result of one node or gauss point, should be written in the same line.

Note: for Matrix and PlainDeformationMatrix results, the Si, Sii and Siii components are calculated by GiD, which represents the eigen values & vectors of the matrix results, and which are ordered according to the eigen value.

Nodal ResultGroup example: 


ResultGroup "Load Analysis" 1 OnNodes
  ResultDescription "Ranges test" Scalar
    ResultRangesTable "My table"
  ResultDescription "Scalar test" Scalar
    ResultRangesTable "Pressure"
  ResultDescription "Displacements" Vector
    ComponentNames "X-Displ", "Y-Displ" "Z-Displ"
  ResultDescription "Nodal Stresses" Matrix
    ComponentNames "Sx", "Sy", "Sz", "Sxy", "Syz", "Sxz"
Values
    1 0.0           0.00000E+00 0.00000E+00  0.00000E+00 0.0 0.55014E+00  0.97276E-01 -0.15427E+00 0.0 0.0 0.0
    2 6.4832835e-01 0.20855E-04 0.20855E-04 -0.19174E-04 0.0 0.50676E+00  0.33886E-01 -0.10559E+00 0.0 0.0 0.0
    3 0.0           0.35517E-04 0.35517E-04 -0.37637E-04 0.0 0.37765E+00  0.44121E-02 -0.54703E-01 0.0 0.0 0.0
...

  115 7.8873599e-01 0.42781E-04 0.42781E-04 -0.17594E-03 0.0 0.15692E-01 -0.15847E-01 -0.30077E-01 0.0 0.0 0.0
  116 7.4978158e-01 0.24357E-04 0.24357E-04 -0.18974E-03 0.0 0.21668E-02 -0.96841E-02 -0.23115E-01 0.0 0.0 0.0
End Values

Gauss Points ResultGroup example: 


GaussPoints "My Gauss" ElemType Triangle "2D Beam"
  Number Of Gauss Points: 3
  Natural Coordinates: Internal
End gausspoints

ResultGroup "Load Analysis" 1 OnGaussPoints "My Gauss" 
  ResultDescription "Gauss test"  Scalar
  ResultDescription "Vector Gauss" Vector
  ResultDescription "Gauss Points Stresses" PlainDeformationMatrix
Values
  1 1.05   1 0                      0.0     -19.4607 -1.15932 -1.43171 -6.18601           
    2.1	   0 1                      0.0     -19.4607 -1.15932 -1.43171 -6.18601           
    3.15   1 1                      0.0     -19.4607 -1.15932 -1.43171 -6.18601           
  2 1.2	   0 0                      0.0     -20.6207 0.596461 5.04752 -6.00727            
    2.25   0 0                      0.0     -20.6207 0.596461 5.04752 -6.00727            
    3.3	   2.0855e-05 -1.9174e-05   0.0     -20.6207 0.596461 5.04752 -6.00727            
  3 1.35   2.0855e-05 -1.9174e-05   0.0     -16.0982 -1.25991 2.15101 -5.20742            
    2.4	   2.0855e-05 -1.9174e-05   0.0     -16.0982 -1.25991 2.15101 -5.20742            
    3.45   2.0855e-05 -1.9174e-05   0.0     -16.0982 -1.25991 2.15101 -5.20742            
...

191 29.55  4.2781e-05 -0.00017594   0.0     -0.468376 12.1979 0.610867 3.51885            
    30.6   4.2781e-05 -0.00017594   0.0     -0.468376 12.1979 0.610867 3.51885            
    31.65  4.2781e-05 -0.00017594   0.0     -0.468376 12.1979 0.610867 3.51885            
192 29.7   4.2781e-05 -0.00017594   0.0     0.747727 11.0624 1.13201 3.54303              
    30.75  4.2781e-05 -0.00017594   0.0     0.747727 11.0624 1.13201 3.54303              
    31.8   2.4357e-05 -0.00018974   0.0     0.747727 11.0624 1.13201 3.54303              
End Values



Results example

Here comes an example of results for the table of the previous example (see section Mesh example): 


GiD Post Results File 1.0

GaussPoints "Board gauss internal" ElemType Triangle "board"
  Number Of Gauss Points: 3
  Natural Coordinates: internal
end gausspoints

GaussPoints "Board gauss given" ElemType Triangle "board"
  Number Of Gauss Points: 3
  Natural Coordinates: Given
      0.2 0.2
      0.6 0.2
      0.2 0.6
End gausspoints

GaussPoints "Board elements" ElemType Triangle "board"
  Number Of Gauss Points: 1
  Natural Coordinates: internal
end gausspoints

GaussPoints "Legs gauss points" ElemType Linear
  Number Of Gauss Points: 5
  Nodes included
  Natural Coordinates: Internal
End Gausspoints	

ResultRangesTable "My table"
# el ultimo rango es min <= res <= max
      - 0.3: "Less"
  0.3 - 0.9: "Normal"
  0.9 - 1.2: "Too much"
End ResultRangesTable

Result "Gauss element" "Load Analysis" 1 Scalar OnGaussPoints "Board elements"
Values
    5     0.00000E+00 
    6     0.20855E-04 
    7     0.35517E-04 
    8     0.46098E-04 
    9     0.54377E-04 
   10     0.60728E-04 
   11     0.65328E-04 
   12     0.68332E-04 
   13     0.69931E-04 
   14     0.70425E-04 
   15     0.70452E-04 
   16     0.51224E-04 
   17     0.32917E-04 
   18     0.15190E-04 
   19    -0.32415E-05 
   20    -0.22903E-04 
   21    -0.22919E-04 
   22    -0.22283E-04 
End Values

Result "Displacements" "Load Analysis"  1  Vector OnNodes
ResultRangesTable "My table"
ComponentNames "X-Displ", "Y-Displ", "Z-Displ"
Values
    1    0.0   0.0   0.0
    2   -0.1   0.1   0.5
    3    0.0   0.0   0.8
    4   -0.04  0.04  1.0
    5   -0.05  0.05  0.7
    6    0.0   0.0   0.0
    7   -0.04 -0.04  1.0
    8    0.0   0.0   1.2
    9   -0.1  -0.1   0.5
   10    0.05  0.05  0.7
   11   -0.05 -0.05  0.7
   12    0.04  0.04  1.0
   13    0.04 -0.04  1.0
   14    0.05 -0.05  0.7
   15    0.0   0.0   0.0
   16    0.1   0.1   0.5
   17    0.0   0.0   0.8
   18    0.0   0.0   0.0
   19    0.1  -0.1   0.5
End Values

Result "Gauss displacements" "Load Analysis" 1 Vector OnGaussPoints "Board gauss given"
Values
    5    0.1  -0.1   0.5
         0.0   0.0   0.8
         0.04 -0.04  1.0
    6    0.0   0.0   0.8
        -0.1  -0.1   0.5
        -0.04 -0.04  1.0
    7   -0.1   0.1   0.5
         0.0   0.0   0.8
        -0.04  0.04  1.0
    8    0.0   0.0   0.8
         0.1   0.1   0.5
         0.04  0.04  1.0
    9    0.04  0.04  1.0
         0.1   0.1   0.5
         0.05  0.05  0.7
   10    0.04  0.04  1.0
         0.05  0.05  0.7
        -0.04  0.04  1.0
   11   -0.04 -0.04  1.0
        -0.1  -0.1   0.5
        -0.05 -0.05  0.7
   12   -0.04 -0.04  1.0
        -0.05 -0.05  0.7
         0.04 -0.04  1.0
   13   -0.1   0.1   0.5
        -0.04  0.04  1.0
        -0.05  0.05  0.7
   14   -0.05  0.05  0.7
        -0.04  0.04  1.0
         0.05  0.05  0.7
   15    0.1  -0.1   0.5
         0.04 -0.04  1.0
         0.05 -0.05  0.7
   16    0.05 -0.05  0.7
         0.04 -0.04  1.0
        -0.05 -0.05  0.7
   17    0.0   0.0   0.8
        -0.04 -0.04  1.0
        -0.04  0.04  1.0
   18    0.0   0.0   0.8
         0.04  0.04  1.0
         0.04 -0.04  1.0
   19    0.04 -0.04  1.0
         0.04  0.04  1.0
         0.0   0.0   1.2 
   20    0.04 -0.04  1.0
         0.0   0.0   1.2
        -0.04 -0.04  1.0
   21   -0.04 -0.04  1.0
         0.0   0.0   1.2
        -0.04  0.04  1.0
   22   -0.04  0.04  1.0
         0.0   0.0   1.2
         0.04  0.04  1.0
End Values

Result "Legs gauss displacements" "Load Analysis" 1 Vector OnGaussPoints "Legs gauss points"
Values
    1   -0.1  -0.1   0.5
        -0.2  -0.2   0.375
        -0.05 -0.05  0.25 
         0.2   0.2   0.125
         0.0   0.0   0.0
    2    0.1  -0.1   0.5
         0.2  -0.2   0.375
         0.05 -0.05  0.25 
        -0.2   0.2   0.125
         0.0   0.0   0.0
    3    0.1   0.1   0.5
         0.2   0.2   0.375
         0.05  0.05  0.25 
        -0.2  -0.2   0.125
         0.0   0.0   0.0
    4   -0.1   0.1   0.5
        -0.2   0.2   0.375
        -0.05  0.05  0.25 
         0.2  -0.2   0.125
         0.0   0.0   0.0
End Values



Re-meshing and adaptivity

If the same meshes are used for all the analysis the following section can be skipped.

A new concept has been introduced in Postprocess: Group to allow the postprocess of problems which require re-meshing or adaptive meshes.

Meshes which belongs to a group should be defined between the pair 

Group "group name"
MESH "mesh_name" dimension ...
...
end elements

MESH "another_mesh" ...
...
end elements
end group

Results which are referred to one of the groups should be written between the pair 

OnGroup "group name"
Result "result name"
...
end values
...
end ongroup

Note: As of GiD version 7.7.3b only one group is allowed at a time, i.e., one group can be defined across several steps of the analysis and only one. Care should be taken so that groups do not overlap inside the same step/analysis.

For instance, an analysis which is 10 steps long:

There are two ways to postprocess this:

Old postprocess results format

This file is a complete list of the dumped results, where each result will be organized as follows:

Set 1: Header. Results description

The total number of lines in this set is 1, composed by 1 character string, 1 integer, 1 real, 1 optional character string what depends on the first integer, plus 3 integers:

descr_menu load_type step_val [load_desc] data_type data_loc desc_comp ["gauss_points_name"]

where:

Set 2: Description of the components

The description of each one of the result's components, without any blank spaces inside, should be described here if needed, one per line. The number of lines will be as follows:

This description will appear in different menus to select the variable to be displayed at each stage.

Note: GiD also supports 2D results types, so description components can be two for vectors, and three or four for matrix and plane strain analysis, respectively.

Set 3: Results

The total number of lines in this set is the total number of points if data_loc = 1 or the total number of elements multiplied by the number of Gauss points per element if data_loc = 2. The definition of the results is itemized below.

i result[i]

i result_x[i] result_y[i] result_z[i] result_m[i]

i result_Sxx[i] result_Syy[i] result_Szz[i] result_Sxy[i] result_Syz[i] result_Sxz[i]

i result_Si[i] result_Sii[i] result_Siii[i] result_Vi_x[i] result_Vi_y[i] result_Vi_z[i] result_Vii_x[i] result_Vii_y[i] result_Vii_z[i] result_Viii_x[i] result_Viii_y[i] result_Viii_z[i]

i euler_ang_1[i] euler_ang_2[i] euler_ang_3[i]

Note: for Matrix and PlainDeformationMatrix results, the Si, Sii and Siii components are calculated by GiD, which represents the eigen values & vectors of the matrix results, and which are ordered according to the eigen value.

Results on GaussPoints: When defining results on Gauss Points using the new Gauss points format, i.e. giving a "gauss_points_name" on the Result's Header description, the results should be given on a per element basis specifying the element number only once. For instance:

assuming a three gauss points set named "GaussTriang" has been defined over triangles, there are only two triangles, then a supposed 'Displacement' result will look like this: 

GaussDISPLAC.   2    1    2    2    0 "GaussTriang"
    5    0.1  -0.1   0.5
         0.0   0.0   0.8
         0.04 -0.04  1.0
    6    0.0   0.0   0.8
        -0.1  -0.1   0.5
        -0.04 -0.04  1.0



Gauss Points (Old format)

Note: Next is described the old Gauss Points file format for the old results file format. However, the new Gauss Points file format (see section Gauss Points) is also compatible with the old results format.

Gauss Points: To include the Gauss points in the results, they must be treated as if they were a type of result, but:

- they must be inserted at the beginning of the file,

- the header structure is the same as of the results ones, but the meaning changes.

Note: At the time only Gauss Points on Lines, Triangles and Quadrilaterals, and one Gauss Point for Tetrahedras and Hexahedras are supported inside GiD.

Set 1: Header. Gauss points

The total number of lines in this set is also 1, but it is composed always now by one character string, one integer, one real plus three integers:

descr_menu load_type step_val data_type data_loc desc_comp

where:



Old postprocess mesh format

The old postprocess mesh format is still compatible with this version of GiD. The files containing the postprocess mesh (in the old file format) can be separated into two categories:

Postprocessing data files are ASCII files and must be in a specific format, which is explained below. Each mesh information file can only handle one type of element.





Old format - File ProjectName.flavia.msh

Set 1: Header

The total number of lines in this set is 6. All of them are free lines for any use. This will be the case of the first five lines, which may have an information role, informing about the project name, current version, as well as extra comments that can seem useful to add. Although they can be skipped, they are kept as a particular option inside GiD (comment lines) and as an utility to comment some additional information, like the type of project, equations, conditions and others.

Note: It is advisable, as it occurs in different solver modules used by GiD, that the sixth line explains the contents of the seventh line.

Set 2: General mesh data

The total number of lines in this set is 1, composed by at least 3 integers, the 4th integer is optional:

n_3D_mesh_elements n_3D_mesh_points n_element_type [ last_node]

where:

The third parameter is used by the program to recognize what kind of finite element is being used. To do this in a standard way, GiD considers the following finite element types:

Set 3: Free line for any use

The total number of lines in this set is 1, which is a free line for any use, though most modules inside GiD write here the word 'Coordinates' to point the meaning of the following lines.

Set 4: Coordinates

The total number of lines in this set is n_3D_mesh_points, one for each nodal point, composed by 1 integer plus 3 reals numbers:

i x_coord[i] y_coord[i] z_coord[i]

where:

All the points of the meshes of the domain have to appear in this file.

Set 5: Free line for any use

The total number of lines in this set is 1, which is a free line for any use. The same comments used for set number 3 are valid here, with the change of including the word 'Connectivities' instead of 'Coordinates'.

Set 6: Connectivities

The total number of lines in this set is n_3D_mesh_elements, composed by 1 integer plus n_nodes/element integers and 1 optional integer more:

j node[j][1] node[j][2] ... node[j][n_nodes/element] mat[j]

where:

The nodal connections must follow some specifications, so, for each tetrahedral element with four nodes, the rule is that the first three nodes that form a triangular face must be so sorted in order to define a normal which points towards the semi space containing the fourth node.

The vector mat[j] holds the material index of the element number j.



Old format - File ProjectName.flavia.bon

Set 1: Header

The total number of lines in this set is 6. All of them are free lines for any use. All the comments relative to the header of ProjectName.flavia.msh remain valid for the current file ProjectName.flavia.bon.

Note: It is advisable, as it occurs in different calculation modules included in GiD, that the sixth line explains the contents of the seventh line. Set 2: General boundary data

The total number of lines in this set is 1, composed by at least 3 integers, the 4th integer is optional:

n_bound_elements n_bound_points n_element_type [ last_node]

where:

For the third parameter, GiD considers the following finite element types:

Set 3: Free line for any use The total number of lines in this set is 1, which is a free line for any use, though most modules inside GiD write here the word 'Coordinates' to point the meaning of the following lines.

Set 4: Coordinates The total number of lines in this set is n_bound_points, one for each nodal point, composed by 1 integer plus 3 reals:

i x_coord[i] y_coord[i] z_coord[i]

where:

All the points of the domain have to appear in this file, what includes all the mesh points introduced in ProjectName.flavia.msh at the beginning. Once all the volumetric mesh had been introduced, it is possible to add surfaces that belong to a boundary of the domain but do not belong to a volumetric mesh and by this reason they will not appear in ProjectName.flavia.msh and only in ProjectName.flavia.bon.

Set 5: Free line for any use The total number of lines in this set is 1, which is a free line for any use. The same comments used for set number 3 are valid here, with the change of including the word 'Connectivities' instead of 'Coordinates'.

Set 6: Connectivities The total number of lines in this set is n_bound_elements, composed by 1 integer plus n_nodes/element integers and 2 optional integers more:

j node[j][1] node[j][2] ... node[j][n_nodes/element] set[j]

where:

The vector set[j] allows to distinguish groups of elements in different sets. It applies, for instance, in the case of defining the different conditions that the element fulfills.



Old format - File ProjectName.flavia.dat

Set 1: Header

The total number of lines in this set is 6. All of them are free lines for any use. The first five lines, which may have an information role, informing about the project name, current version, as well as extra comments that can seem useful to add. Although they can be skipped, they are kept as a particular option inside GiD (comment lines) and as an utility to comment some additional information, like the type of project, equations, conditions and others.

Note: It is advisable, as it occurs in different solver modules used by GiD, that the sixth line explains the contents of the seventh line. Set 2: General mesh data

The total number of lines in this set is 1, composed by at least 3 integers, the 4th integer is optional:

n_2D_mesh_elements n_2D_mesh_points n_element_type [ last_node]

where:

The third parameter is used by the program to recognize what kind of finite element is being used. To do this GiD considers the number of nodes that the finite element type uses. So,

Set 3: Free line for any use The total number of lines in this set is 1, which is a free line for any use, though most modules inside GiD write here the word 'Coordinates' to point the meaning of the following lines.

Set 4: Coordinates The total number of lines in this set is n_2D_mesh_points, one for each nodal point, composed by 1 integer plus 3 reals:

i x_coord[i] y_coord[i]

where:

All the points of the domain have to appear in this file, what includes all the mesh points introduced in ProjectName.flavia.msh at the beginning. Once all the volumetric mesh had been introduced, it is possible to add surfaces that belong to a boundary of the domain but do not belong to a volumetric mesh and by this reason they will not appear in ProjectName.flavia.msh and only in ProjectName.flavia.bon.

Set 5: Free line for any use The total number of lines in this set is 1, which is a free line for any use. The same comments used for set number 3 are valid here, with the change of including the word 'Connectivities' instead of 'Coordinates'.

Set 6: Connectivities The total number of lines in this set is n_2D_mesh_elements, composed by 1 integer plus n_nodes/element integers and 2 optional integers more:

j node[j][1] node[j][2] ... node[j][n_nodes/element] set[j]

where:

The vector set[j] allows to distinguish groups of elements in different sets. It applies, for instance, in the case of defining the different conditions that the element fulfills.

Note: The numeration of quadratic elements is linear and not hierarchical, i.e. nodes should be specified counterclockwise, without jumping internal nodes.

Go to the first, previous, next, last section, table of contents.