...
Components of spatial display
Spatial Display
The Spatial Display grid can show time series of any kind: scalar, polygon, or grid (see the figures below for examples). The data is shown on a map background. The time on the display is set using a ruler that can be moved by hand or set to move on its own.
The spatial display is made up of the following parts:
- A spatial, grid, or map display with layers that you can change
- A Control Toolbar with general options for:
- Zooming in and out and moving around
- Turning map layers or metadata on and off, like labels, values, flags, thresholds, etc.
- A Time Slider Toolbar with general options (found at the bottom of the map since 2019.02):
- Buttons for play, pause, stop, step forward, step backward, and record
- A time slider with a time slice indicator
- An indicator for data availability and maximum value (the colors match the legend)
- Filters for selecting what to show in the Spatial Display (you can set up plots ahead of time)
- A table or bar legend (you can choose to accumulate data)
- Options for exporting or recording data and time series
Control Toolbar
The toolbar offers controls for presenting the spatial information through various buttons. The functionality of zoom options and layers is detailed in the FEWS Explorer section. (see chapter 2).
Button | Description |
|---|---|
| Contours. You can turn contour lines on or off. Numbers show up when the animation is stopped or paused. The colors, which show the value, stay visible. A bilinear interpolation is used to make the grid smooth. This is necessary for calculating the contours. Even when the labels and contour lines are turned off, the smooth grid can still be seen. The bilinear interpolation is only used on the cells of the grid that are rectangular and aren’t rotated too much compared to the screen orientation. |
| Grid lines. Toggles grid or polygon lines on or off |
| Product Info. Toggles product info on or off. (only shown if there are products present in the configuration, see the page on the Forecast Product Information Panel) |
| Labels. You can toggle labels on or off. The drop-down options include turning locations, values, and/or units in the labels on or off, and increasing or decreasing the number of decimals shown in the labels and tooltips. Since FEWS 2022.02, this also works for grids, but only when you zoom in until there are fewer than 20,000 grid cells displayed and one of the cells is larger than 10 pixels. |
| Value to local reference level. |
| Flags. Switches to flags for selected time series / gridplot (quality, modifiers or thresholds) |
| Search and select forecasts. Switches to (previous) forecasts. |
| Show spatial thumbnails. Toggles thumbnails of each time step below the main spatial display on or off. |
| Show spatial ensemble thumbnails. Displays the ensemble thumbnails panel. |
| Sketch mode buttons and other sketch drawing options. Switches the sketch mode between drawing points, adding points, drawing longitudinal profiles and drawing areas when the map is clicked. Contains additional options to save/load sketches and delete the current sketch. |
| Options to show a graph based on current sketch. Drop-down menu with options to extract scalar time series, vertical profiles, longitudinal profiles, 2D longitudinal profiles, calculate budget and calculating the mean max min time series (for sketched areas). |
| Activate spatial modifier mode. Toggles spatial modifier mode on or off (only shown if at least one spatial modifier is configured in ModifierTypes.xml). The additional modifier mode buttons shown when modifier mode is toggled on are explained in the spatial modifier section. |
| Display time. Choose display time (period) |
| Attributes. |
...
The time slider and its buttons have been moved to a separate toolbar located at the bottom of the spatial display.
| Preload. The preload button allows the grids for all time steps to be downloaded in the background. This ensures a smooth animation without pauses. The progress of the download is indicated by a green line on the time slider. | ||
| Play. Starts continuous play mode. The slider will indicate the time slice being shown. This button is merged with the pause button. So after this button is pressed, the pause button appears. | ||
| Pause. Stops continuous play mode. The time slider remains at the time displayed at the moment. This button appears if the play button is previously pressed and the continuous play mode is running. | ||
| One frame back. Moves the time slider back one timestep. | ||
| One frame forward. Moves the time slider forwards one timestep. | ||
| Record. This function creates a movie file in AVI or animated GIF format. By default, the AVI format is used unless the filename ends with ‘.gif’. Once the file is opened, the display will start playing from the current time position and will continue until the stop button is clicked. | ||
| Time Slider | The time slider can be dragged to specific time slice. | ||
Data availability | The data availability indicator gives a visual hint about where data can be found. When data is available, the color of the data availability indicator will match the highest value found in the data for that time slice.
|
Selection filters
The selection filters indicate which displays have been set up. You can select a filter to show the data. Keep in mind that each grid display might be set up differently, for example, they might show data from different periods, use different background maps, and so on. The configuration allows certain filters to be highlighted in bold.
Locations attribute filter
With the location attribute filters, you can hide one or more locations/grids in the plot. The button ( 
) is only visible when attributes are configured for the plot.
Legend
The legend can be displayed as a table or a bar. It identifies the color associated with each range of values. You can rescale the range of values for each color by right-clicking on the display and choosing ‘Rescale Classification’ from the pop-up menu. The display colors will then be updated to match the new classification. After rescaling, the lowest and highest values in the legend will match the minimum and maximum values of the data in the current zoom extent of the display (for the selected time slice). If you zoom in on an area where all data points or grid cells have similar colors, you can use rescaling to better see the differences in data values. To go back to the default classification, right-click on the display and choose ‘Back To Default Classification’ from the pop-up menu. When you select a different plot, the classification always reverts back to the default for that plot.
...
Since the 2023.02 the accumulation slider automatically contains an extra tick at the end of the slider do accumulate the time steps to/from the display time
Last Value Checkbox
When this checkbox is selected, it displays the last available time series configured in the grid plot. This can be handy when there are multiple time series with different or non-equidistant time steps defined within one grid plot, and a time is selected where one time series doesn’t have a time step. The time series can be either scalar or grid. For scalars, the last time step (that is still within the visible period) without a missing value is shown. For grids, just the last time step is shown, even if it might be a missing value. The checkbox will only appear when neither an accumulation nor a moving average slider has been configured, and it can be hidden through configuration.
Selecting different forecasts
...
The button (
) can be used to open the spatial ensemble thumbnails panel.
The spatial ensemble thumbnails window will open, displaying a thumbnail for each individual ensemble member at the selected time.
A time slider is also displayed at the bottom of the window and allows the user to change the selected time both on the spatial thumbnails window and the rest of the spatial display.
In this window, users can choose the ensemble thumbnail they want to view. This selected ensemble member will then be visualized in the grid display.
...
To begin, press the button "Connect to the external data source."(
) FEWS will then start looking for the data relevant for the display in the OpenArchive.
Contours
The contour button generates contours in real-time for the grids being displayed. Since 2021.01, it’s also possible to show contours for irregular grids and across multiple grids displayed simultaneously. When the contour button is pressed, bilinear interpolation is used to calculate a value for each pixel individually. The grid display knows the grid cell for every pixel at the current map extent and zoom level. The detection of neighboring cells is done at the screen pixel level and works for existing configurations. The interpolation is automatically turned off for individual cells that are not rectangular or are rotated more than 10 degrees compared to the screen. The contours are calculated for the interpolated pixel values for the current zoom extent. The contour button is disabled for point data and when contours are configured for a different parameter on top of the parameter that is using the colors from the legend.
Extracting data from the Spatial Display
...
Extracting scalar time series for each ensemble member at one from grid
Since the 2020.01 version, it’s possible to display the scalar time series for each ensemble member for a single grid cell.
Extracting vertical profiles from 3D data
...
The priority controls the order in which spatial modifiers are applied. This can be relevant if spatial modifiers have areas that overlap. For example, you may wish to create a spatial modifier for a large area, then modify a smaller subarea in a different way with a second spatial modifier. Modifiers are applied from the one with the highest value for priority to the one with the lowest value (so a modifier with priority 1 will be applied after a modifier with priority 2). This causes the modifier with the lowest value to be "on top". By default the priority is set to 1. In the previous example, you should set the priority of the modifier for the large area to a higher number, so the spatial modifier for the smaller area will appear on top (with default priority of 1). When two spatial modifiers have the same priority, there is no guarantee they will be applied in a certain order.
Validity
The validity options allow setting the forecast(s) a spatial modifier should be applied to. There are two options:
...