This icon is a plotting specification for Hovmøller diagram plots from a suitable GRIB data source. It can also take the output from a Hovmoeller Data icon as an input. In this case, a consistency check is performed between the parameters that are common to both icons. In addition to the parameters required for the Hovmøller diagram computation, this icon specifies the axis details as well as the plot positioning in the plot frame of the display window / paper sheet and the overlay of different data units in the same plot. To access the computed output values use the icon Hovmoeller Data.
Further details on the role and usage of View icons in the visualisation process, please see Views. The macro language equivalent is mhovmoellerview(). |
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The Hovmoeller View Editor
Type
Specifies the type of the Hovmøller diagram to be produced. Options are:
Area Hovm - diagram derived from an input rectangular area.
Line Hovm - diagram derived from an input transect line
Vertical Hovm - diagram derived from an input rectangular area and a set of levels.
Line (Line Hovm)
Specifies the coordinates of a transect line along which the Hovmøller diagram is calculated. Enter the coordinates (lat/long) of a line separated by a "/" (lat1/long1/lat2/long2). Alternatively, use the coordinate assist button.
Area (Area Hovm or Vertical Hovm)
Specifies the coordinates of the area over which the Hovmøller diagram is calculated. Enter the coordinates (lat/long) of an area separated by a "/" (top left lat and long, bottom right lat and long). Alternatively, use the coordinate assist button.
Average Direction (Area Hovm)
Specifies the direction along which the averaging of the variable is performed. Options are North South and East West. For North South, the averaging is weighted by cos(latitude).
Date Min
Specifies the horizontal date minimum value. Default value AUTOMATIC indicates that the minimum value will be taken from the input data.
Date Max
Specifies the horizontal date maximum value. Default value AUTOMATIC indicates that the maximum value will be taken from the input data.
Bottom Level (Vertical Hovm)
Specifies the vertical lower limit value, as a pressure level (hPa) or model level (η levels).
Top Level (Vertical Hovm)
Specifies the vertical upper limit value, as a pressure level (hPa) or model level (η levels).
Swap Axes
By default, the definition of the vertical and horizontal axes of the Hovmøller diagrams follows pre-defined rules. However, if Swap Axes is set to Yes then the axes will be swapped around.
Resolution
Used to interpolate the data onto a regular grid, and applies to both the horizontal and vertical axes where appropriate. This parameter is essential for creating a Hovmøller diagram from satellite data.
Time Axis
Specifies the characteristics of the time-series axis to be used in the plotting of the data. An Axis Plotting icon can be dropped here. The following Axis parameters are defined by the application; therefore, users cannot change their values directly: Axis Type (set to Date), Axis Date Min Value and Axis Date Max Value (set according to the above parameters Date Min and Date Max, respectively), and Axis Orientation.
The Axis Orientation parameter is defined according to the following rules:
a) if the selected input pane is Line Hovm, the value is set to Horizontal;
b) if the selected input pane is Area Hovm and the Average Direction is East West, the value is set to Horizontal
c) if the selected input pane is Area Hovm and the Average Direction is North South, the value is set to Vertical.
d) if the selected input pane is Vertical Hovm, the value is set to Horizontal.
However, it is possible to change the Axis Orientation value from its calculated default by setting parameter Swap Axes to Yes. This option is not available for Vertical Hovm.
