| Tecplot
Graphs
Two Dimensional Graphs
Tecplot is very flexible when drawing graphs.
It can do the following, the ones with links are discussed in this
document.
To draw a graph
using tecplot, just read in your one
dimensional data . The graph will appear.
There are many things that you can do with the
graph. Click on the "Plot Attributes..." button. If you don't see
the "Plot Attributes..." button - either "Object Details..." or
"Tool Details..." appears in its place - be sure to click the arrow
in the tools palette, and then click the left mouse button anywhere
on the screen that is not over text, a graph or such. When you click
on the "Plot Attributes..." button, you will see the following.
From this menu, you can control how the
graph is plotted. The various features are broken down by category:
"Definitions", "Lines", "Curves","Symbols", .... To select the category,
click on the appropriate button. The categories, definitions, lines
and symbols will be discused.
- Definitions:
You can assign a variable to the x-axis and to the y-axis. To
assign a variable to the y-axis, just click on "Y-Axis Variable".
A window will pop up. Choose the variable that you to use for
the vertical axis. The x-axis is handled in a similar manner.
- Lines: Select the "Lines" category to
set line color, line width, line style (Solid, dotted, dashed,
...), line color and more. Just point and click.
- Symbols (Scatter
Plots): To show a symbol (square, circle) at the data points,
click on the box next to "Symbols" in the upper left corner of
the tecplot window. If you just want to see symbols - no line
connecting the points - unselect the "Lines" in the upper left
corner. In the "Plot Attributes" window, click on "Symbols". You
should see the following.
From here, you can select the symbol shape,
outline color, fill color, size and spacing. Just click on the
appropriate button. To control the spacing, click on "Symb Spacing"
and then click on "Iskip=2", "Iskip=3" or "Iskip=4" which will
draw the symbol at every second, third or fourth point respectively.
If this is still too many. Use the "Enter Index..." option to
manually enter a skip value.
Controlling the Axis.
To adjust the axes, including tick marks, labels,
and length, pull the "Axis" menu down to "Edit...". You will see
the following
Across the top, is a list of axes that
you can display and modify. Select the desired axis. In the above
the "X1" axis is selected. A modification occurs only on the selected
axis.
Here everything but range is easy to use, just
remember "Labels" means the numbers that appear next to the tick
marks, and "Title" means the name of the variable.
The range option can be confusing.
- If one of the axis is too long, you can change
the range. There are several things to set before you change the
range. Unselect "Preserve Length when Changing Range" and select
"Independent".
- If you want to change the range to zoom in,
select "Preserve Length when Changing Range" and select "Dependent".
You may have to enter a ratio to determine the scale of the axis.
- You can also change the scale by selecting
the arrow from the tools palette, clicking on an axis, then dragging
a resize handle (a black square) to change the size of the plot.
Note: This changes the scale of all axes.
Preserving the length keeps the axis the same
length, the scale changes.
When things go wrong, pull down the "View" menu
to "Data Fit". Tecplot will do its best to fit the data to the frame.
Plotting Multiple Data
Sets Tecplot can plot multiple data sets.
The easiest way to plot multiple data sets is to
create a file containing all the data set, each data set is
a zone in the file. In the "Plot Attributes" window, you can turn
on and off various zones. Just click on the desired zone (that is,
click on the line that are listed by map number), or click and drag
to choose multiple zones, then click on the "Map Show" button. You
can then activate or deactivate the selected zone(s).
You can also plot multiple data sets that are
in different files. The easiest way to do this is to read all the
data sets in at once.
- Pull the "File" menu down to "Load Data
File(s)...". You will see the following window.
- Click on "Multiple Files". This window
will change. Enter the name of each of the file that you want
to read in. Between each file either press the return key or click
on the "Add" button. When all files have been selected, press
"OK".
- The first file will be plotted. To plot the
other files, click on "Plot Attributes..." Select the desired
data set - each data set is assigned a map number corresponding
the order that you selected the data files - by clicking on the
line contining the desired map or by clicking and dragging to
select multiple maps. Now click on the "Map Show" button and activate
or deactivate.
- You may have to pull the "View Menu" down
to "Data Fit" to view all the data sets.
Multiple
Graphs Multiple Axes
You can show multiple axis when you have multiple
data sets.
In the "Plot Attributes" window, select "Definitions".
Now click on "Which Y-Axis", and redraw. That's it. You can modify
the new axis by pulling down the "Axis" menu to "Edit" and selecting
the appropriate axis
Three Dimensional Graphs
Tecplot can draw three dimensional graphs. Read
in your data, then click on the "3D button in the upper left corner
of the tecplot window, then redraw. As with 2D graphs, you can play
with the axis labels, major and minor grid marks, grid background.
To do so, pull down the "Axis" menu to "Edit". Click on the desired
button and enter the desired settings for each axix.
XY
Plotting Exercises
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