vtk_fortran_vtk_file

VTK file class.

Source: src/lib/vtk_fortran_vtk_file.f90

Dependencies

Contents

• vtk_file
• get_xml_volatile
• free
• initialize
• upper_case
• finalize

Derived Types

vtk_file

VTK file class.

Components

Name	Type	Attributes	Description
xml_writer	class(xml_writer_abstract)	allocatable	XML writer.
xml_reader	type(xml_reader)		XML reader (initialize(..., action='read')).
is_reading	logical		The file is open for reading.

Type-Bound Procedures

Name	Attributes	Description
get_xml_volatile	pass(self)	Return the eventual XML volatile string file.
initialize	pass(self)	Initialize file.
finalize	pass(self)	Finalize file.
free	pass(self)	Free allocated memory.

Subroutines

get_xml_volatile

Return the eventual XML volatile string file.

Attributes: pure

subroutine get_xml_volatile(self, xml_volatile, error)

Arguments

Name	Type	Intent	Attributes	Description
self	class(vtk_file)	in		VTK file.
xml_volatile	character(len=:)	out	allocatable	XML volatile file.
error	integer(kind=I4P)	out	optional	Error status.

Call graph

free

Free allocated memory.

Attributes: elemental

subroutine free(self, error)

Arguments

Name	Type	Intent	Attributes	Description
self	class(vtk_file)	inout		VTK file.
error	integer(kind=I4P)	out	optional	Error status.

Call graph

Functions

initialize

Initialize file: open it for writing (default) or for reading.

@note This function must be the first to be called.

Reading

With action='read' only filename is used: the file is indexed and its data are then read through the xml_reader component (get_info, read_piece, read_geo, read_connectivity, read_polydata_cells, get_dataarray_names, get_dataarray_info, read_dataarray); finalize frees it. Its format, topology, header type and compressor come from the file. The error codes of reading are listed in the vtk_fortran_vtk_file_xml_reader module.

 type(vtk_file)         :: vtk
 real(R8P), allocatable :: x(:), y(:), z(:), pressure(:)
 error = vtk%initialize(filename='mesh.vtu', action='read')
 error = vtk%xml_reader%read_geo(x=x, y=y, z=z)
 error = vtk%xml_reader%read_dataarray(location='node', data_name='pressure', x=pressure)
 error = vtk%finalize()

Writing

format and mesh_topology are required.

Supported output formats are (the passed specifier value is case insensitive):

• ASCII: data are saved in ASCII format;
• BINARY: data are saved in base64 encoded format;
• RAW: data are saved in raw-binary format in the appended tag of the XML file;
• RAW-ZLIB: shorthand of RAW with compressor='zlib';
• BINARY-APPENDED: data are saved in base64 encoded format in the appended tag of the XML file.

Compression of binary data

The optional compressor compresses the data of the binary formats (BINARY, RAW, BINARY-APPENDED) as VTK does (vtkZLibDataCompressor, blocks of 32 KiB): none (default) or zlib, case insensitive; it is ignored by the ASCII format. zlib needs the library built with VTKFORTRAN_USE_ZLIB: otherwise, as for an unknown compressor, initialize returns a non-zero error. RAW-ZLIB with compressor='none' is an error too.

Bytes count header of binary data

Each binary DataArray (formats BINARY, RAW, RAW-ZLIB, BINARY-APPENDED) is prefixed by its bytes count (by the header of its compressed blocks, when compressed). The optional header_type selects its width: UInt32 (default) limits each DataArray to 2 GiB (larger ones stop the execution with an explicit error), UInt64 lifts the limit; it is case insensitive and ignored by the ASCII format.

Supported topologies are:

• RectilinearGrid;
• StructuredGrid;
• UnstructuredGrid;
• ImageData: a regular grid, defined by the extents and the origin, spacing (both required) and direction (optional) arguments; the point of indexes (i,j,k) is at origin + direction . ([i,j,k] * spacing). No geometry is written (write_geo is not used).
• PolyData: points (write_geo(np, nc, x, y, z)) and up to four cell blocks (vertices, lines, triangle strips, polygons) written with write_polydata_cells; the piece is opened with write_piece(np, nverts, nlines, nstrips, npolys).

Example of usage

 type(vtk_file) :: vtk
 integer(I4P)   :: nx1, nx2, ny1, ny2, nz1, nz2
 ...
 error = vtk%initialize('BINARY','XML_RECT_BINARY.vtr','RectilinearGrid',nx1=nx1,nx2=nx2,ny1=ny1,ny2=ny2,nz1=nz1,nz2=nz2)
 ...
 error = vtk%initialize('BINARY','XML_UNST_ZLIB.vtu','UnstructuredGrid',compressor='zlib')
 ...

@note The file extension is necessary in the file name. The XML standard has different extensions for each different topologies (e.g. vtr for rectilinear topology). See the VTK-standard file for more information.

Returns: integer(kind=I4P)

function initialize(self, format, filename, mesh_topology, is_volatile, nx1, nx2, ny1, ny2, nz1, nz2, origin, spacing, direction, header_type, compressor, action) result(error)

Arguments

Name	Type	Intent	Attributes	Description
self	class(vtk_file)	inout		VTK file.
format	character(len=*)	in	optional	File format: ASCII, BINARY, RAW, RAW-ZLIB or BINARY-APPENDED.
filename	character(len=*)	in		File name.
mesh_topology	character(len=*)	in	optional	Mesh topology.
is_volatile	logical	in	optional	Write into memory (get_xml_volatile): ascii and binary only.
nx1	integer(kind=I4P)	in	optional	Initial node of x axis.
nx2	integer(kind=I4P)	in	optional	Final node of x axis.
ny1	integer(kind=I4P)	in	optional	Initial node of y axis.
ny2	integer(kind=I4P)	in	optional	Final node of y axis.
nz1	integer(kind=I4P)	in	optional	Initial node of z axis.
nz2	integer(kind=I4P)	in	optional	Final node of z axis.
origin	real(kind=R8P)	in	optional	Origin of ImageData: coordinates of the point of indexes (0,0,0).
spacing	real(kind=R8P)	in	optional	Spacing of ImageData along each axis.
direction	real(kind=R8P)	in	optional	Axes directions of ImageData, row-major 3x3 matrix (default identity).
header_type	character(len=*)	in	optional	Bytes count header of binary data: UInt32 (default) or UInt64.
compressor	character(len=*)	in	optional	Compressor of binary data: none (default) or zlib.
action	character(len=*)	in	optional	Action: write (default) or read, case insensitive.

Call graph

upper_case

Return a string in upper case (ASCII letters only).

Attributes: pure

Returns: character(len=len(string))

function upper_case(string) result(upper)

Arguments

Name	Type	Intent	Attributes	Description
string	character(len=*)	in		Input string.

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finalize

Finalize file: close the writer, or free the reader.

Returns: integer(kind=I4P)

function finalize(self) result(error)

Arguments

Name	Type	Intent	Attributes	Description
self	class(vtk_file)	inout		VTK file.

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