Description - The primary purpose of the FunctionFilter is to apply user specified transformations to data. For the specific coordinate transformations that will be helpful with SWIFT data, we have the CoordConvertFilter. This filter is more general than that, but not as user friendly because the user had to type in the functions. With this filter the user gets to specifically define the format of the elements that come out of the filter. Both the parameters and the values can be specified as functions of the elements of the input datasets. For convenience we have provided options that will mirror the parameters and values of the first input dataset. This also allows the user to take values from parallel datasets and merge them together into single elements. If, for example, you wanted the first value output from the filter to be the first value of the first input and the second value output to be the first value of the second input you could have the first function be d[0].v[0] and the second one be d[1].v[0].

Using a function filter in conjunction with a sequence source is a convenient way to plot a function in SWIFTVis. This can be used for overploting lines. For simple transforms remember that the plot styles also accept functions so in some cases the function filter can be skipped if it doesn't feed into another filter.

Inputs - This filter accepts multiple inputs. It only makes sense if they are parallel data sets though.

Elements - The format of the output elements is determined by the options the user selects for this filter.

Memory - This filter is somewhat memory intensive because it has to be. It creates new elements using the given functions for the full range of indices that are valid for the formulas.