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.
For further details on the role and usage of View icons in the visualisation process, please see Analysis Views.
The macro language equivalent is mhovmoellerview().
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).
Time Axis Mode
Specifies the direction of the date/time axis. Options are:
- User (default) - Left/bottom date is taken from the Date Min parameter and the right/top date is taken from the Date Max parameter.
- Automatic Forwards - Date limits are taken from the data and plotted left to right or bottom to top.
- Automatic Backwards - Date limits are taken from the data and plotted right to left or top to bottom.
Option Automatic Forwards has the same effect as option User with default Date Min and Date Max.
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. Only an Axis Plotting icon can be dropped here. The following axis parameters are defined by the application; therefore, users should not 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.
Geo Axis
Specifies the characteristics of the geographical axis to be used in the plotting of the data. Only an Axis Plotting icon can be dropped here. The following axis parameters are defined by the application; therefore, users should not change their values directly: Axis Min Value and Axis Max Value (set according to the values given by parameters Line or Area), Axis Type, Axis Tick Label Type and Axis Orientation. The Axis Type and Axis Tick Label Type parameters are defined according to the following rules:
a) if the selected input pane is Line Hovm, the Axis Type value is set to Geoline.
b) if the selected input pane is Area Hovm and the Average Direction is East West, the Axis Type value is set to Regular and Axis Tick Label Type to Latitude.
c) if the selected input pane is Area Hovm and the Average Direction is North South, the Axis Type value is set to Regular and Axis Tick Label Type to Longitude.
Moreover, 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 Vertical
b) if the selected input pane is Area Hovm and the Average Direction is East West, the value is set to Vertical
c) if the selected input pane is Area Hovm and the Average Direction is North South, 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.
Vertical Axis (Vertical Hovm)
Specifies the characteristics of the level-series axis to be used in the plotting of the data. Only an Axis Plotting icon can be dropped here. The following axis parameters are defined by the application; therefore, users should not change their values directly: Axis Min Value and Axis Max Value (set according to the input data set), Axis Type, Axis Tick Label Type and Axis Orientation.
Vertical Level Type (Vertical Hovm)
Specifies if a conversion from model level to pressure level needs to be performed. Options are As In Data and Pressure, If the conversion to pressure is selected and the input data is specified in model levels, the LNSP field should be added to the input data.
Vertical Scaling (Vertical Hovm)
Specifies the type of vertical axis - Linear or Logarithmic.
Specifies the X offset of the plot from the left side of the plot frame (any subdivision of the display area). This is expressed as a percentage of the X-dimension of the plot frame. Specifies the Y offset of the plot from the bottom side of the plot frame (any subdivision of the display area). This is expressed as a percentage of the Y-dimension of the plot frame. Specifies the X length of the plot. This is expressed as a percentage of the X-dimension of the plot frame. Hence the sum of this X length plus the X offset cannot exceed 100 (it is advised that it does not exceed 95 since you need some margin on the right for things like axis or map grid labels). As above but for the Y length of the plot. Toggles the plotting of a border line around the plot frame On /Off . Comprising Page Frame Colour, Page Frame Line Style and Page Frame Thickness, these parameters specify the characteristics of the plot frame border line. Only available when Page Frame is On . Toggles the plotting of plot identification line On /Off . Specifies user text to be added to the plot identification line. Only available when Page Id Line is On . Toggles the plotting of a border line around the plot itself On /Off . In most cases you will want this to be left On . When Off the sides of the plot not equipped with axis will not be plotted. Comprising Subpage Frame Colour, Subpage Frame Line Style and Subpage Frame Thickness, these parameters specify the characteristics of the plot frame border line. Only available when Subpage Frame is On . Specifies the colour of the background of the plot (i.e. not affected by visual definitions like contour shadings or lines). Subpage X Position
Subpage Y Position
Subpage X Length
Subpage Y Length
Page Frame
Page Frame Parameters
Page Id Line
Page Id Line User Text
Subpage Frame
Subpage Frame Parameters
Subpage Background Colour