When the DEFINE PLOT button in the Plot Selection Menu is clicked it pops up a single instance of the Plot Definition Menu. This menu in turn immediately spawns two additional menus: the Axis Definition Menu and the Plot Label Menu. The latter two menus are created silently, that is they do not immediately pop up onto the screen but will show up in the Menu Page List in the Control Panel. The Plot Definition Menu has the form:
NOTE: Older and alternate forms of this menu do exist. Most of the differences are in the layout.
The purpose of the Plot Definition is to establish the type of plot begin set up. This is completely determined through the set of Function Of options. The remaining options on the menu mostly determine the layout and resolution of the plots.
A plot definition occupies a given area in the plot page.
Within this region the total number of plots generated by the plot definition are arranged on a rectangular grid of plot which is Plot Cols wide by Plot Rows high.
Note: Multiple plots within a plot definition can occur in a number of ways. Two of the most prevalent are: specifying that each plot contain some fraction of the total plot time requested; selecting multiple sources to and specifying that each must occupy a unique plot.
If it can, the UDF plot program will fill all of the plots within the plot matrix for a given plot definition. If there are additional plots to produce these will be output on succeeding plot pages.
By setting either or both the Plot Cols and Plot Rows values to -1, the UDF plot program can be made to make its best guess at setting up the plot grid. The program only considers the number of plots needed to ensure that all of the selected UDF sources will appear on the plot page. It does not consider the need for multiple plots based on temporal considerations.
Output Fmt sets the display mapping used when plotting the data. The options are:
| Option | Definition |
|---|---|
| CARTESIAN | Generic rectangular coordinate system. |
| MERCATOR | Map coordinate system using a Mercator projection. |
| SINUSOIDAL | Map coordinate system using a Sinusoidal projection. |
| MOLWEIDE | Map coordinate system using a Molweide projection. |
| ECKERT SINE | Map coordinate system using an Eckert Sinusoidal projection. |
| ECKERT ELLIPSE | Map coordinate system using an Eckert Ellipsoidal projection. |
| POLAR | Map coordinate system using a polar projection. |
| AZIMUTHAL | Map coordinate system using an azimuthal projection. This is a 3D projection which can be rotated in both longitude and latitude. |
| CONIC | Map coordinate system using an conic projection. |
Data plotted in a Map coordinate system (any but the first option) are restricted to 0 to 360 (or -180 to 180) in longitude (phi) and 0 to 180 (or -90 to 90) in latitude (theta). The X-axis must be a function PHASE ANGLE and the Y-axis a function of THETA.
Plot Axis Ratio sets the ratio of the displayed X-Y axis lengths of all plots within the plot definition. The available options are:
| Option | Definition |
|---|---|
| ARBITRARY | Each plot will fill the area available to it. This option is generally used in conjunction with CARTESIAN plots. |
| SQUARE | Forces the X and Y axis to have the equal lengths. The option is used generally in conjunction with the Azimuthal Output Format to keep the spherical projections as true spheres. |
| SCALING RATIO | Forces the ration of the X and Y axis lengths to have the same as the ratio as the axis scaling. This is used generally in conjunction with the mapping output formats to keep the plots in perspective. It is also useful on CARTESIAN plots where the X and Y axis have identical units (eg. contour plots ). |
Specifies the direction to take when plotting multiple plots within the plot matrix. The first plot produced in a plot matrix is always the upper left-hand plot and the last the lower right-hand plot. The available options are:
| Option | Definition |
|---|---|
| ACROSS | Successive plots are filled across the Rows of the plot matrix. |
| DOWN | Successive plots are filled down the Columns of the plot matrix. |
Allows for the timing of the plots defined in the plot definition to be linked to the timing of plots produced through a previous plot definition. This option is only active when the defined plots do not have a TIME AXIS associated with them. The value given is the plot definition number (the first plot definition is plot definition 0) and must be a value less than that of the current plot definition. A value of -1 disables this feature.
Time alignment is useful when producing plots:
This option corrects for the fact that each plot definition plots independent of all other definitions. What can happen in this case is you can define two series of Phi/Theta plots from two separate data sources. Each plot covers one spin in time. Should either source be missing data for one or more spins of data, the two sets of plots will loose their time alignment. The Time Align option will prevent this. The Master Plot Definition will plot as defined, but the Slave Plot Definitions(s) will have their plot times synced to those produced in the Master so that missing data will show up as a blank plot in the sequence.
Allows the user to choose whether the sources will start at the beginning time of the first selected source that was defined or at the beginning of the defined time.
| Option | Definition |
|---|---|
| YES | This option will sync all sources' time to the beginning of the first source's time. |
| NO | This option is the default setting which allows each source to plot from its own designated time. |
Plot Tools contains a list of algorithms which can be used either to manipulate the data prior to the data being plotted or to add features to the plot after it is completed. Each of the available Tools generates its own menu page and the details of each will be taken up in separate sections. The options available under Plot Tools are:
| Option | Definition |
|---|---|
| Flow Removal | For array data which is a function of energy, this option allows the energy to be corrected for an external flow. |
| Show Vector | Projects an arbitrary vector onto a theta/phi (Map) plot. Useful for showing a magnetic field or a flow vector. |
| Contour | Allows the data to be passed through a Contouring filter for smoothing and iteration purposes. |
| Show Globe or Show Object | Plots either a 2-D or 3-D projection of the Earth on a theta/phi (Map) plot. Used generally in "all sky" satellite image data. It may also hilight a given postion on a plot. |
CLOSE closes the Plot Definition menu window.
The Function Of option line defines which variables are to be plotted against which axis. In essence this specifies the format of the plots within the Plot Definition.
The option lines provides for source definitions for the X-Axis the Left Y-Axis, and the Right Y-Axis. In the current rendition of the UDF plot program the Right Y-Axis source selection is not used. This option is intended to allow a line plot to be plotted over the top of a spectrogram or like plot which uses the Right Y-Axis but is as yet unimplemented.
There are a number of source definitions available to be plotted against the X-Y axes. These definitions determine where the needed data is found within a UDF or IDFS input source definition. Most of the time the data is returned directly from the UDF or IDFS when the data is accessed but sometimes the data may need to be retrieved from the VIDF. The source definitions include:
| Option | Definition |
|---|---|
| Time | Axis is a function of the measurement time. Time is restricted to be plotted along the X-axis. |
| Value | Scalar data. If the source is data of a higher dimension the higher dimension will be collapsed. |
| Scan | Axis is a function of the array indices associated with a Vector or Matrix sources. |
| Phase Angle | Axis is a function of the phase angle associated with the measurement. Value is computed in the UDF kernel and returned with the measurement. |
| Pitch Angle | Axis is a function of the pitch angle associated with the measurement. Value is computed in the UDF kernel when defined in the VIDF and returned with the measurement. |
| Theta Angle | Axis is a function of the theta or elevation angle associated with the measurement. Value is generally obtained from the VIDF. If no value exists then the program will assume that the theta value is returned through the scan indices. |
| Source Number | Axis is a function of the VIDF source number of the measurement if the measurement is derived from a Scalar or Vector source. For a Matrix the axis is a function of the matrix column number. |
| Statistics | Axis is a function of the number of occurrences of the values in a Scalar measurement. When selecting statistics for an axis the remaining axis will be automatically set to value. |
| Contour | Axis is part of a contour plot. The opposing axis will be set the same. |
| Anc Scan | The axis is a function of one of the sensor ancillary data sets. This allows an Ancillary Data Value to be substituted for the sensor scan data in a plot. |
The relationship between some common plot definitions and the axis definitions are given below. With the exception of plot definitions containing a Time axis, the axis definitions are reversible. Non-implemented plot formats are indicated.
| Plot | X Axis | Left-Y Axis | Implemented |
|---|---|---|---|
| Spectrogram | Time | Scan | YES |
| Spectrogram | Time | Anc Scan | YES |
| Spectroscalar | Time | Value | YES |
| Line Plot | Time | Value | YES |
| Contour | Contour | Contour | YES |
| Energy/Angle | Scan | Phi | YES |
| Statistics Plot | Statistics | Value | YES |
| Scatter Plot | Value | Value | NO |
| Spectra | Scan | Value | YES |
NOTE: the Minimum and Maximum settings for most of the plot axes are defaulted when the UDF source is selected. Which axes are set and what they are set to depends on the current Function Of settings. Because of this it is a good idea when building a UDF Plot Menu to have the Function Of settings set before the sources are selected.
Plot Gaps determines the algorithm used to fill in gaps in the plotted data along the X and Y axes. The UDF Plot Program plots to a predefined grid and it is possible to make the plot grid fine enough to introduce gaps in the plot (grid locations where no data is placed). This is often times a desired effect since the algorithms to fill in the missing grid values can be used to smooth data. If gaps in the plot grid occur and are to fill both along X and Y, then gaps are filled first along Y and then X. The Plot Gap options which are identical for both axis, are:
| Option | Definition |
|---|---|
| IGNORE | Do nothing. Let the gaps show as gaps in the plot. |
| HOLD (MID) | Fill any gap in the plot grid by taking the first filled plot grids on either side of it and then duplicating these values to the middle of the gap. |
| HOLD (END) | Fill any gap in the plot grid by taking the first filled plot grid below it (filling in Y) or to the left of it (filling in X) and duplicating this value to cover the gap. |
| LINEAR FILL | Fill any gap in the plot grid by taking the first filled plot grids on either side of it and then using a linear interpolation to fill in empty grids. |
Data Storage sets the method used when storing the data in the plot grid. The option is independently set for both X and Y axis. The options are:
| Option | Definition |
|---|---|
| BAND | If the data has a range over which it is valid then stretch the data over that range in the plot grid. In general this should be set for the time axis. |
| POINT | Store the data as if it were a scalar value with no range. |
Note: With the exception of the UDF Time variable, all variables are currently stored as POINT measurements no matter what option is selected. This situation will be removed in a later release.
The Time Binning line of options establishes the necessary timing information. The information is used differently depending of whether the plots have a time-based axis or not.
When a plot has a time-based axis, the plot grid is setup so that there is one to one correspondence between the number of plot grid points and the output device pixels along the X-axis (time axis). The Time Binning options establish the time duration per X plot grid. If a plot definition has no time-based axis then Time Binning information is used to determine the interval of time covered by the plot.
METHOD establishes how the timing is to be determined. The options are:
| Option | Definition |
|---|---|
| BY PLOT TIME | Each plot spans the entire time range defined in Plot Specification Menu - Beginning Time to Ending Time. For a time-based plot this time divided by the number of plot grids establishes the time per plot grid. |
| USER DEFINED | A time interval will be set to use as either the time per plot grid or the time per plot depending on whether the plot has a time-based axis or not. This is established through the next options on the line. |
INTERVAL is accessible only if the Time Binning METHOD option has been set to USER DEFINED. It sets the value of the time interval to be used when defining either the duration of a plot or the duration of a plot grid. The time base of the set interval is selected in the next option. Note: When a time interval is defined for either a plot or a plot grid, the plotting of data quits whenever the end time of the current plot exceeds the end time set in the Plot Specification Menu but not until the final plot is plotted in its entirety.
TIME UNITS is accessible only if the Time Binning METHOD option has been set to USER DEFINED. The option sets the time base of the time INTERVAL established in the previous option. The TIME UNITS options are:
| Option | Definition |
|---|---|
| YEARS | The duration is specified in terms of years. |
| DAYS | The duration is specified in terms of days. |
| HOURS | The duration is specified in terms of hours. |
| MINUTES | The duration is specified in terms of minutes. |
| SECONDS | The duration is specified in terms of seconds. |
| MILLISECONDS | The duration is specified in terms of milliseconds. |
| MICROSECONDS | The duration is specified in terms of microseconds. |
| NANOSECONDS | The duration is specified in terms of nanoseconds. |
| SPIN PERIOD | The duration is specified in terms of spin periods. |
| MEASUREMENT | The duration of the Nth source measurement defined under this plot definition. At the current time this only works for matrix sources. |
SOURCE # is accessible only if the Time Binning TIME UNITS option has been set to MEASUREMENT. The option sets which of the defined UDF sources in the plot definition is to be used to set the duration of a plot or plot grid.
The X-AXIS BINNING line of options establishes the plot grid along the X-Axis of the plot when the plot is not time-based. The line of options is inaccessible for time-based plots where the plot grid is established in the Time Binning option line.
METHOD establishes how the grids are to be setup. The options are:
| Option | Definition |
|---|---|
| FROM SOURCE | The number of bins to be set to the number of pixels in the output device along the X-Axis. The values associated with the leading edge of the first grid and the trailing edge of the last grid are obtained from the the minimum and maximum axis scaling respectively. |
| USER DEFINED | The gridding along the X-Axis is set according to the remaining options on the line. |
BEGIN is accessible only if the X-Axis Binning METHOD option has been set to USER DEFINED. It is the value to be associated with the first plot grid along the X-Axis. When this value is changed, hitting a return will transfer the value to the Axis Definition menu putting it in the minumum value option for the X-Axis.
END is accessible only if the X-Axis Binning METHOD option has been set to USER DEFINED. It is the value to be associated with the last plot grid along the X-Axis. When this value is changed, hitting a return will transfer the value to the Axis Definition menu putting it in the maximum value option for the X-Axis.
# OF BINS is accessible only if the X-Axis Binning METHOD option has been set to USER DEFINED. It is the total number of grids to establish along the X-Axis.
LIMITS ARE is accessible only if the X-Axis Binning METHOD option has been set to USER DEFINED. The option sets how to interpret the plot grid BEGIN and END specifications. The options are:
| Option | Definition |
|---|---|
| CENTERS | The BEGIN and END values of the plot grid represent the center value of the first and last grid. |
| ENDS | The BEGIN and END values of the plot grid repsent the leading edge of the first grid and trailing edge of the last grid respectively. |
SCALING is accessible only if the X-Axis Binning METHOD option has been set to USER DEFINED. The option specifies the algorithm to use in computing the centers and edges of the plot grids. The options are:
| Option | Definition | |
|---|---|---|
| LINEAR | The plot grid centers are linearly spaced in X between the centers of the first and last grid. | |
| LOG | The plot grid centers are logarithmically spaced in X between the centers of the first and last grid. |
The Y-AXIS BINNING line of options establishes the plot grid along the Y-Axis of the plot. This line of options is inaccessible if the Y-Axis is defined to be a value-based axis as there is no gridding along a value-based axis.
METHOD establishes how the grids are to be setup. The options are:
| Option | Definition |
|---|---|
| FROM SOURCE | The number of bins is to be set to the number pixels in the output device along the Y-Axis. The values associated leading edge of the first grid and the trailing edge of the last grid are obtained from the the minimum and maximum axis scaling respectively. |
| USER DEFINED | The gridding along the Y-Axis is set according to the remaining options on the line. |
BEGIN is accessible only if the Y-Axis Binning METHOD option has been set to USER DEFINED. It is the value to be associated with the first plot grid along the Y-Axis. When this value is changed, hitting a return will transfer the value to the Axis Definition menu putting it in the minumum value option for the Y-Axis.
END is accessible only if the Y-Axis Binning METHOD option has been set to USER DEFINED. It is the value to be associated with the last plot grid along the Y-Axis. When this value is changed, hitting a return will transfer the value to the Axis Definition menu putting it in the maximum value option for the Y-Axis.
# OF BINS is accessible only if the Y-Axis Binning METHOD option has been set to USER DEFINED. It is the total number of grids along the Y-Axis.
LIMITS ARE is accessible only if the Y-Axis Binning METHOD option has been set to USER DEFINED. The option sets how to interpt the plot grid BEGIN and END specifications. The options are:
| Option | Definition |
|---|---|
| CENTERS | The BEGIN and END values of the plot grid repsent the center value the first and last grid. |
| ENDS | The BEGIN and END values of the plot grid repsent the leading edge of the first grid and trailing edge of the last grid respectively. |
SCALING is accessible only if the Y-Axis Binning METHOD option has been set to USER DEFINED. The option specifies the algorithm to use in computing the centers and edges of the plot grids. The options are:
| Option | Definition |
|---|---|
| LINEAR | The plot grid centers are linearly spaced in Y between the centers of the first and last grid. |
| LOG | The plot grid centers are logarithmically spaced in Y between the centers of the first and last grid. |
The Plot Options line contains a number definitions which effect how the data is displayed.
SOURCES specifies what to do if multiple UDF sources have been selected to be plotted under this Plot Definition. The options are:
| Option | Definition |
|---|---|
| MERGE | The sources are left separate but plotted in the same plot grid (same plot). Data placed in a plot grid is added to whatever is initially there. The grids are normalized before plotting. For plot formats (eg line plots) which have no grids along the scalar-based axis this is equivalent to averaging all the sources together resulting in a single line. |
| SEPARATE | The sources are plotted separately. Line plots are always placed in separate plot grids which are then overlayed in the same plot. In other plot formats the sources are plotted in the same plot grid in overwrite mode (data placed in a plot grid overwrites any other data there). See the STACK option on this line for how to plot to distinct plot grids. |
IN AVERAGES specifies how to handle situations where data is being added into a plot grid in which data already exists. The options are:
| Option | Definition |
|---|---|
| KEEP ZEROS | Zero data is included in all averages. |
| DROP ZEROS | Zero data is excluded from all averages. |
EMPTY PLOTS specifies what to do if a plot is produced within the Plot Definition that is empty, that is no data within the time interval of the plot was found. The options are:
| Option | Definition |
|---|---|
| IGNORE | Do not display plots which have no data in them. |
| KEEP | Display all plots empty or otherwise. |
GAP WIDTH sets the gap between adjacent Line Plots which are output in SpectroScalar format. The SpectroScalar format is set in the process of defining the UDF Source. The gap is set between adjacent plots in the same plot grid and is specified in pixels.
RESYNC determines how to start a plot following an Empty Plot. The options are:
| Option | Definition |
|---|---|
| NO | Do not resync the start time of the plot to the time of the next measurement. There is a gap in time and it will plot the gap. |
| YES | Resync the start time of the next plot grid to the the beginning time of the next measurement. This will eliminate multiple empty plots should they exist. |
STACK indicates how many sources should be included in a plot grid which is equivalent to how many sources should be included in a common plot. It only has meaning when the SOURCES option has been set to SEPARATE.
The option is useful in grouping line plots. As an example, if there are 8 defined sources and STACK has been set to 4 then the plot definition will produce two plots each populated with 4 line plots. For spectrograms setting STACK to a value other than 1 will probably not produce the output desired as in this case the plots generally overwrite one another, with each successive plot erasing the prior plot.
The MAP GRIDS options are accessible only when the data is being projected onto one of the cartographic coordinate systems. (Any OUTPUT FMT option but Cartesian. The options specify how the longitude and latitude grid lines are to be drawn on the plot.
OUTPUT specifies if the longitude and latitude grid lines should be drawn and if they are to be drawn, how they are to be drawn. The options are:
| Option | Definition |
|---|---|
| NONE | No grid lines are to be drawn. |
| OVERLAY | Grid line are added after the plot is drawn. |
| UNDERLAY | Grid line are added before the plot is drawn. |
COLOR is accessible only if the OUTPUT option is not set to NONE. It sets the color of the longitude and latitude grid lines.
DELTA options are accessible only if the OUTPUT option is not set to NONE. This sets the spacing in degrees between the output latitude and longitude grid lines (separate settings for each). Latitude grid lines are drawn from the minimum to the maximum displayable latitude. (See the ENDS). Longitude grid lines are drawn beginning at 0 degrees (Greenwich) and progressing eastward. In the default mode, 0 degrees longitude is always centered in the longitude axis.
ROTATION options are accessible only if the OUTPUT option is not set to NONE. For longitude, this allows the 0 degree longitude to be shifted either to the right (positive rotation) or to the left (negative rotation) in the plot. For latitude the value is only used when OUTPUT FMTS is set to AZIMUTH. Under this option a negative rotation rotates the North Pole toward the equator while a positive rotation rotates the South Pole toward the equator.
ENDS is accessible only if the OUTPUT option is not set to NONE and is selectable only for latitude. The specified value sets both the largest poleward extent of the longitude grid lines and the minimum and maximum displayable latitude grid line. The value is the termination point of the northern latitude grid lines in degrees from the equator (equator being 0 degrees and north pole 90 degrees). The termination of the southern latitude grid lines is the negative of the value given. The option is useful when plotting data in an AZIMUTHAL projection to defeat the convergence of the longitude grid lines in the polar regions.
The MAP OUTliNES options are accessible only when the data is being projected onto one of the cartographic coordinate systems. (Any OUTPUT FMT option but Cartesian. The options deal with the adding of continental outlines to the plot. Note: Continental outlines can be added to a cartographic projection whether they make sense with the data or not!
OUTPUT specifies if the continental outlines should be drawn and if the are to be drawn, how they are to be drawn. The options are:
| Option | Definition |
|---|---|
| NONE | No grid lines are to be drawn. |
| OVERLAY | Grid line are added after the plot is drawn. |
| UNDERLAY | Grid line are added before the plot is drawn. |
COLOR is accessible only if the OUTPUT option is not set to NONE. It specifies the color of the continental outlines.
RESOLUTION is accessible only if the OUTPUT option is not set to NONE. It sets the resolution to be used when drawing the the continental outlines. The resolution is given in terms of points skipped. The continental outlines are stored in a very high resolution format, much higher than can be separated on any output device. In general a resolution of 400 is more than adequate.
DEFINE UDF SOURCE consists of two buttons, the second being used only as a counter. Clicking on DEFINE button will bring up one instance of the Source Definition Menu whose options are discussed in a separate section. Each instance of this menu page defines one or more UDF sources to be included in the Plot Definition.
DELETE PAGE deletes the current Plot Definition and all menus associated with it.
The following examples show the effects of some of the options available through the Plot Definition Menu. The options are demonstrated through two sets of plots, a set of line plots of the IMAGE spacecraft position day 133 of the year 2000 and a phi-theta plot of a neutral IMAGE from the OA experiment. There is no intention here to show all of the various types of plot formats which can be generated. These can be seen under the section showing examples of various Plot Menus.
In its default configuration as shown above, the Plot Definition Menu is set to display a line plot. The sources are plotted as SEPARATE and there is only one source per plot. The top three and bottom three plots are produced by separate but identical Plot Definitions.
Setting the PLOT ROW and COL to 1 and 3 respectively in the first Plot Definition
produces
(Some changes to options in the Plot Label Menu were needed to add separation between the two plot definitions and to get the time Axes labeled on all plots.)
Setting the Stack option to 3 in each Plot Definition
To increase the temporal resolution of the plot change the Time Binning Method from BY PLOT TIME to USER DEFINED. Set Interval to 75 and Time Units to seconds. This changes the per/pixel resolution in the plot to be 75 seconds.
This will produce as many plots as necessary to cover the time period requested. The Plot Definition Menu above is set up to display the first two of these plots. The resultant first plot page is:
The functional definition of a plot axes is set in the Function Of option. In this example this was selected to be Theta and Phase Angle which when combined with the HENA image data will produce a Neutral Atom Image. The Time Binning has been set to give one satellite's spin of data per plot.
In the produced plot the gaps in the data along X are the discrete values of theta in the data. The plot was left with a Plot Axis Ratio of ARBITRARY which causes the plot to fill the available space.
To correct the perspective of the above plot set the Plot Axis Ratio to Scaling ratio. To fill in the gaps along the X axis set the Plot Gap option to HOLD.
This changes the plot to:
X/Y-Axis Binning, Output Format, Map Grids
A phi-theta plot can be projected onto any of the cartographic coordinate system available under the OutPut Fmt option. The AZIMUTH option was selected for this example. NOTE: that the X-Axis has been set to PHASE ANGLE and the Y-Axis to THETA. This is necessary when using the cartographic projections.
To smooth the plot the gridding along both the X-Axis and Y-Axis have been set to give a 1° resolution. This is greater than the image resolution. The Data Storage has been set to POINT for both axis to prevent the data with width from spading over multiple grids. Finally to fill in the holes the Plot Gap option has been set to LINEAR FILL.
Finally the Map Grids have been set to provide a resolution of 25° in latitude and 15° degrees in longitude. There is a downward rotation of the north pole and a counterclockwise rotation in longitude. The longitude lines are truncated at ± 75° latitude.
This results in:
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