For interpolation, wind must be separated into two scalar components, which are then independently interpolated as continuous scalars. Interpolation using the speed and direction components makes good estimates of intermediate wind grids. The same technique can be used to interpolate successfully any continuous vector data. Two known wind vectors with the same length, and directions differing by 90 . 3.3 Categorical Data Weather is described by a combination of three categories for precipitation coverage, type, and intensity.
Weather is displayed and edited as areas with distinct boundaries and labeled with text.
For the purposes of interpolation, weather at a grid point is represented as one or more combinations that may be internally represented by integers. The values are neither continuous nor sequential. Interpolation of one weather category works properly. An area of one weather type may change in position, size, and shape, and intermediate grids are found correctly. However, when two or more weather categories are present, or if a category vanishes or appears, interpolation raises questions which have no well-defined solution.