The Vector Field Renderer function allows you to display your raster with vector symbols. This renderer is often used for visualizing flow direction and magnitude. It can also be used to symbolize a single raster layer that represents either magnitude or direction. For more information about rendering rasters using the Vector Field Renderer function, see Drawing raster data using vector symbols.
There are 13 parameters for this function:
- Input Raster—The input raster can be a multidimensional raster layer, or the output from the Vector Field function.
- Input represents U and V components—This check box determines if the input components represent either magnitude and direction or U and V. The U and V components are for other sets of vectors than magnitude and direction.
- Unchecked—The input data represents magnitude and direction.
- Checked—The input data represents U and V components.
- Magnitude/U component—The input magnitude or the U component. Use the drop-down menu to choose which band you want to use. If Direction is set to None, you will display a scalar value. In this case, the symbol will only be resized—no rotation will occur. This case can be used to visualize data such as salinity or dissolved oxygen. In the case where U is used, the renderer will convert to magnitude on the fly. In the case where V is used, the renderer will convert to direction on the fly.
- Direction/V component—The input direction or V component. Use the drop-down menu to choose which band you want to use. If Magnitude is set to None, the renderer will draw the data with a rotation but with a constant size applied. This is useful for visualizing data such as aspect.
- Reference system—Specifies how the direction component was measured.
- Geographic—The component uses 0 degrees as due north and 90 degrees as due east.
- Arithmetic—The component uses 0 degrees as due east and 90 degrees as due north.
- Angle represents—Specifies the direction of mass flow.
- From—The mass is flowing along the angle and moving toward the origin of the reference system. This is sometimes referred to as the meteorological convention.
- To—The mass is flowing along the angle and moving away from the origin of the reference system. This is sometimes referred to as the oceanographic convention.
- Symbol—Choose the symbol to display your vector field. You have three ways to choose your symbol: you can choose one from the drop-down list, you can use the Symbol Selector window, or you can use the Import button to import a symbol from a feature layer.
- Each symbol represents a tile size—Specify the tile size in screen pixel units or other measurement units. The tile size determines the density of the symbols; the larger the tile size, the fewer symbols appear in display.
- Thinning method—If there are too many pixels in the display, this is used to determine how to calculate the magnitude and direction of the vector symbol.
- Minimum magnitude—The minimum magnitude value. By default, this value is calculated from the input. You may want to modify the minimum magnitude if the input does not have statistics calculated, or the input is U and V components. Tiles with magnitude less than or equal to this value will be rendered with the minimum symbol size.
- Minimum symbol size—Specify the minimum symbol size. It is specified as a percentage of the tile.
- Maximum magnitude—The maximum magnitude value. By default, this value is calculated from the input. You may want to modify the maximum magnitude if the input does not have statistics calculated, or the input is U and V components. Tiles with magnitude greater than or equal to this value will be rendered with the maximum symbol size.
- Maximum symbol size—Specify the maximum symbol size. It is specified as a percentage of the tile.
The thinning method is used to calculate the magnitude and direction value of a tile:
- Vector average—The following calculation occurs for each pixel: convert direction and magnitude to U and V components, calculate the averages of U and V for all pixels in a tile, and then convert the average U and average V back to direction and magnitude.
- Nearest neighbor—Use the value from the pixels closest to the center of the tile.
- Bilinear—Bilinear resampling will be performed on the tile.
- Cubic—Cubic convolution resampling will be performed on the tile.
- Minimum—The minimum pixel value of the tile.
- Maximum—The maximum pixel value of the tile.