AVS Modules sololoadmd
NAME
sololoadmd - read velocity and coordinate information for N point
objects and represent them as spheres color coded by
velocity
SUMMARY
Name sololoadmd
Type Data Input
Inputs None
Outputs "Geom Output" - geom
Parameters Name Type Default Min Max
---- ---- ------- --- ---
filename string null null null
sphere radii float 0.20 0.02 unbound
min speed float 0.0 unbound unbound
max speed float 0.0 unbound unbound
auto scaling boolean 1 0 1
display toggle boolean 1 0 1
DESCRIPTION
This module is a modified version of the genloadmd module that is
intended for use when memory restrictions don't allow the entire data set to
be read into an array. Therefore this modules only reads in one data set at
a time and then discards it when a new set is read in. It has several
enhancements to facilitate use with a single data set at a time. Note also
that the data is expected in a slightly different format than in the
genloadmd mdoule. This module reads in position and velocity information for
a group of point particles in three dimensions, from a file specified as an
input parameter. This parameter can be connected to either the file browser
or the animated filename module depending on the user requirements. The
program represents each point with a sphere at the position specifed and
color coded by the magnitude of the velocity. The colors 0-255 are
specified in the colors.h file and range from blue (slowest) to red
(fastest). Initially the module will compute the minimum and maximum speeds
from the data set read in and echo these back to the parameter widgets. The
user can change the size of the spheres and the min and max values used to
determine the colors of the sphere. Note that if the minimum speed is
greater than or equal to the maximum speed then a message is echoed back to
standard output (the screen) and no action is taken. Sphere color is
determined by a linear interpolation between the minimum and maximum speeds
of the particle velocity magnitude.If the velocity magnitude of a particular
sphere exceeds the maximum speed then it is displayed as white while those
less than the minimum are displayed as black (note: change the background
color if this also is black).
The auto scaling and display switches were added to enable the user
to still have the full functinality provided by the genloadmd mdoule, that
is that the module can determine the min and max speed values for the user
and scale the velocities based on these values. The current min and max
values are reflected in the widgets (a bug is that only 6 significant digits
are displayed but the variable contains more). When auto scaling is on then
the min and max values from the data set currently being read in will be
compared with the preexisting ones and if they produce new extremum then the
widgets are reset and the velocities scaled with the new values. Once the
data is read in if the min/max widgets are modified then the geometry will
be redrawn regardless of the auto scaling setting. Auto scaling off means
that subsequent data sets read in can not override the extremum values. In
conjunction with this option, the no display mode option is also provided.
The intent of this is to allow the user to more quickly cycle through a set
of data and with auto scaling on the module will determine an overall
min/max value for the entire data set. The user can then turn display back
on (and might as well turn scaling off as it will be slightly faster) and
read through the data set again to see it all displayed with one fixed set
scaling parameters. Of course if the user knows a priori the range of the
data set then the widgets can be set directly before any data sets are read
in and both of these switches turned off.
PARAMETERS
Input File
this is the name of the data file and should be in the following
format:
The first line is step number(integer), temperature(float), number
of
particles(integer). Note that step number and temperture are dummy
values that are not currently used. This is followed by one line per
particle each of which starts with a dummy integer particle number
and
is followed by the three x,y,z coordinates (float) and then the
three
velocity components (float) in the x,y,and z directions. This
pattern is
then repeated for each time step, i.e. a header line followed by a
data
line for each particle.
sphere radii
radius of the spheres displayed
min speed
The minimum speed used to determine what color the sphere will be
displayed as. The current value is reflected in the widget, when
auto scaling is turned on then these values are compared with the
values from each data set as it is read in.
max speed
The maximum speed used to determine what color the sphere will be
displayed as. The current value is reflected in the widget, when
auto scaling is turned on then these values are compared with the
values from each data set as it is read in.
auto scaling
turn automatic extremum comparison on or off
display toggle
turn display on or off
OUTPUTS
Geom Output
geometry output to the geometry viewer module
EXAMPLE 1
---------------------
| file browser |
---------------------
|
| ---------------------
| | animated integer |
| ---------------------
| |
| |
| |-----------------|
| |
--------------------- ---------------------
| sololoadmd | | sphere |
--------------------- ---------------------
| |
| |
+--------------------------------|
|
|
---------------------
| geometry viewer |
---------------------
RELATED MODULES
sphere - available from anonymous ftp via the International
AVS Center
SEE ALSO
genloadmd
md_params.h - include file
colors.h - include file
load_mdn
PORTED TO
SGI Personal Iris
IBM RS6000