1 GRID_CUBE A simple gridding task to make a 2D image from a table
GRID_CUBE
This task makes a cube from a table containing data regularly sampled on
a 2-d grid, but possibly uncompletely sampled. Several gridding modes
are possible.
In mode GRID, since the input data is assumed to be regularly sampled,
this gridding task does not use any convolution or interpolation, but
just fills a grid with values.
In mode NATURAL, a convolution kernel is used to interpolate the irregu-
larly sampled data using the weight of each individual point.
In mode UNIFORM, the same convolution process is used but the individual
points are assumed to have equal weight.
The grid step is specified by the user, but the map size can be deter-
mined by the task. The input table can be created by command GRID in
CLASS, or using task TABLE from a formatted file.
2 TABLE$
TASK\CHARACTER "Input TABLE name" TABLE$
Specify the name of the input table.
2 MAP$
TASK\CHARACTER "Output MAP name" MAP$
Specify the name of the output map. The output map will be in VLM order
(Velocity, X coordinate, Y coordinate).
2 XCOL$
TASK\INTEGER "Column of X coordinates" XCOL$
Specify the column of the table containing the X coordinates
2 YCOL$
TASK\INTEGER "Column of Y coordinates" YCOL$
Specify the column of the table containing the Y coordinates
2 WCOL$
TASK\INTEGER "Column for weights" WCOL$
Specify the column containing the weights
2 MCOL$
TASK\INTEGER "First and last column to grid" MCOL$[2]
Specify the first and last column to be regridded. Note that the weight
column can be included in order to produce a weight image. This can al-
low further processing based on Signal-to-Noise ratio.
2 WEIGHT_MODE$
TASK\CHARACTER "Gridding Mode (GRid, NAtural or UNiform)"
WEIGHT_MODE$
Indicate the weight mode. GRID indicates the simple gridding (add the
data point in the corresponding cell), NATURAL indicates a more elabo-
rate convolution with proper weighting, UNIFORM a convolution without
weighting.
2 WMIN$
TASK\REAL "Minimum relative weight" WMIN$
Minimum (relative) weight for a grid point to be significant. Grid
points with lower weights are blanked.
2 MAP_SIZE$
TASK\INTEGER "Map dimensions (0 means Guess)" MAP_SIZE$[2]
Output map size in pixel. Use 0 to leave the program guess.
2 X_AXIS$
TASK\REAL "X Conversion formula (Ref Val Inc)" X_AXIS$[3]
Output map conversion formula for X axis.
2 Y_AXIS$
TASK\REAL "Y Conversion formula (Ref Val Inc)" Y_AXIS$[3]
Output map conversion formula for X axis.
2 TOLE$
TASK\REAL "X-Y position tolerance" TOLE$
Positional tolerance. Points separated less than TOLE$ (on each axis)
are added together before resampling. TOLE$ is essentially useful for
the GRID mode.
2 NPAR$
TASK\INTEGER "Number of additional parameters" NPAR$
Number of parameters for the convolution kernel.
2 PARAMS$
TASK\REAL "Parameters" PARAMS$['NPAR$']
Parameters of the convolution kernel, in pixel units.
1 ENDOFHELP