ism3d.simuv.ft.uv_sample_direct¶
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ism3d.simuv.ft.uv_sample_direct(plane, cell, uu, vv, dRA=0.0, dDec=0.0, PA=0, dimsum='uv', drange=10)[source]¶ runtime scaled with “active” pixel n (loop over active pixel) runtime scaled with nrecord (loop over active visibility) a run time is only acceptable for limited amount of point source
so it’s not using direct sm.predict only give 70% flux and high spatial freuqnecy info is loosing
- sm.predict behavior:
If the input image very small 6x6, loosing flux in sm.predict: It seems its using weighted average over a couple of cells arounds and run into issue for large uv cell (small image cell) case
casa is likley using oversampling method:
oversampling=20 or 20xPB size will make sure any the most rapid perips case (~pb) will be sapled by 20points. such the phase (from joint source of the entire image) can’t change even faster than that. even the nearest neajobour sampling will be good enough and not introduce too much error.