Tecplot Data Formats
Tecplot can read in several data formats,
including structured, unstructured or one dimensional (for graphs). These are ascii files that tecplot
converts to binary using a program called "preplot". Tecplot can
read binary files that have been created by "preplot" or created
by your programs. Your progams should call FORTRAN or C functions
supplied by Tecplot to write the data.
Structured Data
Structured data may be either 1, 2 or 3 dimensional.
We will go through the 2D data formats. The others are similar.
You may use your favorite editor to add the headers to your data.
Spaces and blank lines are ignored by Tecplot
and there are some short cuts that will eliminate a line or two
from the header. See the manual if you are interested in the shortcuts.
You may use either upper or lower case letters. Here is a mesh and
the simple data file that produced it.
title = "sample mesh"
variables = "x", "y", "z"
zone i=5, j=4, f=point
2.000000 5.000000 19.178485
4.000000 7.000000 26.279464
6.000000 9.000000 24.727109
8.000000 11.000000 79.999217
10.000000 13.000000 42.016704
2.000000 8.000000 19.787165
4.000000 10.000000 21.760844
6.000000 12.000000 32.194375
8.000000 14.000000 79.248588
10.000000 16.000000 28.790332
2.000000 11.000000 19.999804
4.000000 13.000000 16.806681
6.000000 15.000000 39.017270
8.000000 17.000000 76.911799
10.000000 19.000000 14.987721
2.000000 14.000000 19.812147
4.000000 16.000000 11.516133
6.000000 18.000000 45.059235
8.000000 20.000000 73.035620
10.000000 22.000000 0.885131
The line "zone i=5, j=4, f=point" states that
we have 20 points in our mesh, the mesh is 5 x 4. Note that the
i index corresponds to the inner loop (the fast loop). That is we
read the data points (suppose they are stored in the array A) as
follows
C Notation Fortran Notation
i=1, j=1 A[1][1] A(1,1)
i=2, j=1 A[2][1] A(2,1)
i=3, j=1 A[3][1] A(3,1)
i=4, j=1 A[4][1] A(4,1)
i=5, j=1 A[5][1] A(5,1)
.
.
.
The first line contains the x,y, and z coordinates
of the first point and so on.
Tecplot accepts other formats. If we change
"f= point" to "f= block", then tecplot expects all the x coordinates,
then all the y coordinates and finally all the zcoordinates. Here
is "f= block" format of the above mesh.
title = "sample mesh"
variables = "x", "y", "z"
zone i=5, j=4, f=block
2.000000 4.000000 6.000000 8.000000 10.000000
2.000000 4.000000 6.000000 8.000000 10.000000
2.000000 4.000000 6.000000 8.000000 10.000000
2.000000 4.000000 6.000000 8.000000 10.000000
5.000000 7.000000 9.000000 11.000000 13.000000
8.000000 10.000000 12.000000 14.000000 16.000000
11.000000 13.000000 15.000000 17.000000 19.000000
14.000000 16.000000 18.000000 20.000000 22.000000
19.178485 26.279464 24.727109 79.999217 42.016704
19.787165 21.760844 32.194375 79.248588 28.790332
19.999804 16.806681 39.017270 76.911799 14.987721
19.812147 11.516133 45.059235 73.035620 0.885131
In this format, the number of entries per line
does not matter.
Unstructured
Data
Tecplot can read in unstructured (finite element)
ascii data. This data can be either two or three dimensional. We
will go through 2D data formats, 3D is similar. You may use your
favorite editor to add the headers to your data. Spaces and blank
lines are ignored by Tecplot. You may use either upper or lower
case letters. Here is a simple data file.
title = "Sample finiteelement data"
variables = "x", "y", "a","b"
zone n=5, e=4, f=fepoint, et=triangle
0.0 0.0 1.0 2.0
1.0 1.0 0.0 2.2
1.0 1.0 0.0 3.0
1.0 1.0 0.0 3.4
1.0 1.0 0.0 1.1
1 2 3
1 3 4
1 4 5
1 5 2
In this example, the elements are triangles.
You may also use "quadrilateral" ("tetrahedron" or "brick" in 3D).
The "n=5, e=4" means that there are 5 points and 4 triangles. Each
point has 4 numbers associated with it, the variables called "x",
"y", "a" and "b". The entry "f= fepoint" means that the points in
the data file are arranged as follows
x y a b
x y a b
x y a b
That is, there is a line for each point and each line contains 4 numbers.
If we had used "f= feblock" instead, then Tecplot would expect all
the xcoordinates first, then all the ycoordinates, followed by
the a's and finally the b's. That is,
x x x x .... x
y y y y .... y
a a a a .... a
b b b b .... b
The title may be omitted.
One Dimensional
For graphs, tecplot has several data formats.
Only the simplest one is described here.
The simplest data format that tecplot for graphs
is a list of points. For example:
x1 y1
x2 y2
x3 y3
.
.
.
No header is necessary. You may have more
than two coordinates per line. For example
x1 y1 u1 v1
x2 y2 u2 v2
x3 y3 u3 v3
.
.
.
From within tecplot, you can then select the
variable to use for the xaxis and the variable for the yaxis.
Multiple
Zones
Tecplot allows your data files to have more
than 1 zone. All you need to do is add a line similar to the line
that starts with zone as in the above examples to your data file.
The data following the zone defines the zone. Any or all of the
zones may be displayed.
