---
name: "h5tovtk"
section: "1"
platform: "linux"
package: "h5utils"
version: "1.13.2-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/h5tovtk"
---

# h5tovtk(1)

convert datasets in HDF5 files to VTK format

## NAME

h5tovtk - convert datasets in HDF5 files to VTK format

## SYNOPSIS

**h5tovtk** \[*OPTION*\]... \[*HDF5FILE*\]...

## DESCRIPTION

h5tovtk is a program to generate VTK data files from multidimensional datasets in HDF5 files.  VTK, the Visualization ToolKit, is an open-source, freely available software system for 3D computer graphics, image processing, and visualization.  VTK itself is a programming library, but it is also the basis for a number of end-user graphical visualization programs.

HDF5 is a free, portable binary format and supporting library developed by the National Center for Supercomputing Applications at the University of Illinois in Urbana-Champaign.  A single *h5* file can contain multiple datasets; by default, *h5tovtk* takes the first dataset, but this can be changed via the **-d** option, or by using the syntax *HDF5FILE:DATASET*.

1d/2d/3d datasets are converted into 3d VTK  datasets.  Normally, a single scalar VTK dataset is output, but vectors and fields can be output via the **-o** option below.

A typical invocation is of the form 'h5tovtk foo.h5', which will output a VTK data file foo.vtk from the data in foo.h5.

## OPTIONS

- **-h**

  Display help on the command-line options and usage.

- **-V**

  Print the version number and copyright info for h5tovtk.

- **-v**

  Verbose output.

- **-o** *file*

  Save all the input datasets to a single VTK *file*.  If there is only one dataset, it is output to a VTK scalar dataset; if there are three datasets, they are output as a VTK vector dataset; all other numbers of datasets are combined into a VTK field dataset.

  Otherwise, the default behavior is to save each dataset to a separate VTK file, with the .h5 suffix of the input filename replaced by .vtk in the output filename.

  Only three-dimensional datasets may be written to the VTK file.  If you have a four (or more) dimensional data set, then you must take a three-dimensional "slice" of the multi-dimensional data.  To do this, you specify coordinates in one (or more) slice dimension(s), via the **-xyzt** options.

- **-1**, **-2**, **-4**

  Use 1 , 2, or 4 bytes to store each data point in the output file.  Fewer bytes require less storage and memory, but will decrease the resolution in the values. **-1** will break up the data values into one of 256 possible values (on a linear scale from the minimum to the maximum value in your data), **-2** will allow 65536 possible values, and **-4** (the default) will use 4-byte floating-point numbers for an "exact" representation.

- **-a**

  Output in ASCII format; otherwise, VTK's more compact, but less readable and somewhat less portable binary format is used.

- **-n**

  For binary output (see **-a** above), by default the data is written in bigendian byte order, which is normally the order that VTK expects.  However, some external tools and a few VTK classes use the native byte ordering instead (which may not be bigendian), and the **-n** option causes *h5tovtk* to output binary data in the native ordering.

- **-m** *min*, **-M** *max*

  When **-1** or **-2** are used, the input data are converted to a linear integer scale. Normally, the bottom and top of this scale correspond to the minimum and maximum values in the data.  Using the **-m** and **-M** options, you can make the bottom and top of the scale correspond to *min* and *max* instead, respectively.  Data values below or above this range will be treated as if they were *min* or *max* respectively.  See also the **-Z** option.

- **-Z**

  For **-1** or **-2** output, center the linear integer scale on the value zero in the data.

- **-r**

  Invert the output values (map the minimum to the maximum and vice versa).

- **-x** *ix*, **-y** *iy*, **-z** *iz*, **-t** *it*

  This tells *h5tovtk* to use a particular slice of a multi-dimensional dataset.  e.g. **-x** uses the subset (with one less dimension) at an x index of *ix* (where the indices run from zero to one less than the maximum index in that direction).  Here, x/y/z correspond to the first/second/third dimensions of the HDF5 dataset. The **-t** option specifies a slice in the last dimension, whichever that might be.  See also the **-0** option to shift the origin of the x/y/z slice coordinates to the dataset center.

- **-0**

  Shift the origin of the x/y/z slice coordinates to the dataset center, so that e.g. -0 -x 0 (or more compactly -0x0) returns the central x plane of the dataset instead of the edge x plane.  (**-t** coordinates are not affected.)

- **-d** *name*

  Use dataset *name* from the input files; otherwise, the first dataset from each file is used. Alternatively, use the syntax *HDF5FILE:DATASET*, which allows you to specify a different dataset for each file. You can use the *h5ls* command (included with hdf5) to find the names of datasets within a file.

## BUGS

Send bug reports to S. G. Johnson, stevenj@alum.mit.edu.

## AUTHORS

Written by Steven G. Johnson.  Copyright (c) 2005 by the Massachusetts Institute of Technology.