Clarification of Resize parameters

[kempodragon]

All of the Resize functions have as part of their parameters the inclusion of the the source dimensions. FitCd uses these when creating its Avisynth scripts, but I don't see the difference between leaving them out or including them. The documentation doesn't say what adding the source parameters does for the Resize function. Could someone please explain how adding the source parameters affects the resizing compared to just using the desired dimensions and the coefficients?

[Manao]

Resizer(output_width, output_height, parameters, src_left, src_top, src_width, src_height)is equivalent tocrop(src_left, src_top, src_width, src_height).Resizer(output_width, output_height, parameters)That allows you to select a part of the picture and resize it to the output dimensions.