March 23, 1998 Design News
Reviews on tools of the trade
Tecplot eases graphing
Paris C. Altidis, Staff Engineer
Borg Warner Automotive Inc.
Tecplot eases the task
of graphing and visualizing complex data structures
in engineering. Minimum requirements: An 80486
PC with 16 Mbytes of RAM and 20 Mbytes hard
drive space. Supports all versions of Windows.
$995 for Windows 3.1, 95, and NT; $2,195 for
Amtec Engineering, Inc.,
Box 3633, Bellevue, WA 98009
ph: (800) 676-7568
A similar product:
IDL - Research Systems Inc.,
2995 Wilderness Place, Boulder, CO 80301
ph: (303) 786-9900
fax: (303) 786-9909.
The Windows version of Tecplot features a new user
interface and a slew of features. Suitable for applications
involving huge amounts of data, Tecplot can easily sort
and plot with one of its 2- and 3-D graphics tools.
Because Tecplot has no way to generate raw data that
need to be plotted, it is a graphing tool for users
with advanced needs. Tecplot is being used in disciplines
where the amount of data is more than you can generate
on-the-fly. The data file needs to be of a specific
format before it is imported into Tecplot. Tecplot can
read standard ASCII, binary in 32- or 64-bit floating
point, long and short integers, bytes, and bit data
files. Tecplot does not support Hierarchical Data Format
type for importing data with embedded text annotation
and color images.
The data files have a distinct notation as to how the
data are described. You can have up to three orders
of data, with each order designating the number of parameters
you have available. For a 2-D plot, your data can be
of IJ order (Tecplot's Dimension designation) and for
volumetric data your file will contain IJK ordered data.
With the new tools, turning a volumetric representation
into an XY plot is just a mouse click away.
Despite Tecplot's inability to create the data, it
can manipulate it in a plethora of ways. You can change
or create new data either explicitly or by using mathematical
functions. Apart from the built-in intrinsic functions,
you can mirror, scale, rotate, clip, or extract subsets
of data. The list also includes special operators for
finite differences, derivatives, or gradients. The data
manipulation can be done for one zone or all of them
simultaneously. You can also access your data-generating
application from within Tecplot for further pre-plot
Tecplot can plot your data with any saved style sheet
or use it for other datasets. Often, you may have to
show multiple windows from the same dataset or multiple
datasets. The plots can also be annotated with different
variations of text in any angle and style, and geometric
objects. These objects can also help you create word
charts and 3-D geometries.
In essence, stylesheet and layout files are considered
macro files. But Tecplot uses macros in a more subtle
way, as it allows you to use nested loop sequence, IF
THEN structures, or even logic statements that allow
you to loop within the macro.
As soon as the mesh (the object of what you try to
visualize your data on) is defined, your data can be
displayed as contours, vectors, stream traces, or symbols.
For more complicated cases, you can have your structure
defined as part of your graph and superimpose the data
on top of it. Support of DXF or IGES would have made
the structure definition faster, but it is not included.
Tecplot can represent the core of volumetric datasets
in several ways, such as slicing the volume by adding
cutting planes in a parallel or intersection fashion
at various zones. The data variables are then interpolated
for each slice. Since you can define intersecting zones,
you can define a block and remove it (or blank it) so
that portions of the volumetric core become visible.
New in this version is the addition of blanking using
cylindrical coordinate systems.
Enhancements in Tecplot's macro language help you create
output sequences of data plotting varying, for example,
with respect to time. These sequences can then be played
back with a supplied utility or using your VCR. Although
the speed of animation is strictly a function of hardware,
you still have the animation control to stop, play one
frame at a time, or move forward or backward one frame.
The new enhancements make Tecplot a better solution
for visualizing large sets of data and being productive
within hours of use. It has myriad tools for technical
data presentation, but a lack of OLE functionality prevents
its use from within other Windows applications.