Advanced Plot Options Help
Many of the advanced plotting options are IDL-specific and thus
utilize the plotting capabilities of the Interactive Data Language (IDL),
which is the backend graphics engine used by OMNIWeb.
Greater detailed explanations for these plotting options can be found in the IDL User's Guide and Reference Guide. Rather than duplicate all of IDL's documentation, this document only summarizes the available plotting options.
The advanced capabilities that are supported through OMNIWeb's Data Explorer form are described below:
View Mode:
- Inline Image creates an HTML page as output with an inline GIF image that uses the internal GIF capability of your WWW browser to display GIF images.
- External Image launches the designated GIF viewer specified in your browser's preferences for the image/gif Mime type. Note that the Netscape Navigator sets the default image/gif viewer as inline GIF, so you may want to setup Netscape to use your favorite GIF viewer (such as XV or LView).
- PostScript/Portrait Creates a PostScript file as output in portrait mode. The mime type application/postscript is passed to your browser which may launch a PostScript viewer or prompt to save the file depending on how your browser is configured.
- PostScript/Landscape Creates a PostScript file as output in landscape mode with the same handling as for portrait mode described above.
Paper:
Specify US Letter or A4 to generate a 8.5"x11" or 8.25"x11.75" (210mm x 296mm) PostScript output, which is only applicable when view mode is set to PostScript.
Y-axis scale:
Specify linear or logarithmic scaling of the y-axis, where the default is linear. This option will not change the x-axis scaling for time, which will always be linear.
Character Size:
The overall character size for the annotation. A CHARSIZE of 1.0 is normal. The
main title is written with a character size of 1.25 times this parameter.
X-axis style:
Allows specification of X-axis options such as rounding of tick values
and selection of a box axis. Each option is listed in the table below:
- Default
- Force exact axis range
- Extend axis range
- Suppress entire axis
- Suppress box style axis
Y-axis style:
Allows specification of Y-axis options such as rounding of tick values
and selection of a box axis. Each option is listed in the table below:
- Default
- Force exact axis range
- Extend axis range
- Suppress entire axis
- Suppress box style axis
- Inhibit setting the Y axis minimum value to 0
Plot Symbol:
By default the data points are connected by lines, and no symbols are
drawn to mark the points. The following symbols may be chosen:
- Default (no symbol)
- Plus sign (+)
- Asterisk (*)
- Period (.)
- Diamond
- Triangle
- Square
- X
- Histogram mode
In Histogram mode horizontal and vertical lines connect the plotted points, as opposed to the normal method of connecting points with straight lines.
Symbol Size:
Specifies the size (0.1-4.0) of the symbols drawn when plot symbol is selected. The default value of 1.0 produces symbols approximately the same size as a character.
NSUM:
Indicates the number of data points to average when plotting. If the value
is larger then 1, every group of NSUM points is averaged to produce one plotted
point. If there are m data points, then m/NSUM points are displayed.
On logarithmic axes a geometric average is performed.
It is convenient to use when there is an extremely large number of data points
because it plots fewer points, the graph is less cluttered, and it is quicker.
Resolution:
The data is stored as hourly averaged values (24 records per day), which is
the default resolution to access. The user may also request daily averaged values
to compute the average over every 24-hours of data into a single value.
This is useful for trend analysis of large periods of time. Further averaging and
can be done using the above NSUM option.
Connect Type:
Option to either plot symbols at each point with solid lines connecting the adjoining symbols, or not to connect the points with lines, which applies to all symbols except histogram mode.
Max. Days/Panel:
Specifies the number of days to display in the x-axis of the plots.
The plot will be generated up to this number of days and subsequent time periods
can be plotted as a new plot by clicking on the "More" button on the control panel
when inline GIF images is the selected viewing mode. This option is only applicable
to the default inline image view mode where the output is
a HTML page and a "More" button is available to interactively proceed to the next image.
However, the other plot modes, namely external image and PostScript, will display data
over the entire time period in a single plot.
Color table:
Select the table index (0-40) from among the pre-defined color tables (shown in table below). The default table is 0, which is a standard gray-scale.
0- B-W LINEAR 14- STEPS 28- Hardcandy
1- BLUE/WHITE 15- STERN SPECIAL 29- Nature
2- GRN-RED-BLU-WHT 16- Haze 30- Ocean
3- RED TEMPERATURE 17- Blue - Pastel - R 31- Peppermint
4- BLUE/GREEN/RED/YE 18- Pastels 32- Plasma
5- STD GAMMA-II 19- Hue Sat Lightness 33- Blue-Red
6- PRISM 20- Hue Sat Lightness 34- Rainbow
7- RED-PURPLE 21- Hue Sat Value 1 35- Blue Waves
8- GREEN/WHITE LINEA 22- Hue Sat Value 2 36- Volcano
9- GRN/WHT EXPONENTI 23- Purple-Red + Stri 37- Waves
10- GREEN-PINK 24- Beach 38- Rainbow18
11- BLUE-RED 25- Mac Style 39- Rainbow+white
12- 16 LEVEL 26- Eos A 40- Rainbow+black
13- RAINBOW 27- Eos B
Foreground color index:
The color index (0-255) used to draw the data points.
The default index is 0, which is BLACK for the default color table.
2-red; 3-green; 4-blue;5-yellow.
Background color index:
The background color index (0-255) to which the screen is initially set before drawing anything.
The default index is 255 (white).
Image size (pixels):
The size of image can be adjusted by setting the width (X-axis) to 300-1024
and the height (Y-axis) to 200-1024. The default image size is 640x480
and can be extended up to 1024x1024 or reduced to 300x200
resolutions. Anything less than 300x200 doesn't produce a readable plot given
the space needed for labels and tickmarks.
If you have any questions/comments the system, contact:
Dr.
Natalia Papitashvili,, Mail Code 672, NASA/Goddard Space Flight Center, Greenbelt, MD 20771
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