Hi Yangxing,In Ferret v5.7 the lanczos filter was an external function and not linked into the Ferret executable. If you upgrade to the newer version you will have the lanczos filter (along with all the other additions and improvements from the last 5 years of development.)
Ansley yangxing zheng wrote:
It looks that Mac OS v5.7 ferret (alpha) does not support filter like lanczos filter, do I have to install new version or simply put the function lanczos filter to somewhere? Thanks. Yangxing