tr= getParam( 'timerange', '2000-01-03', 'timerange to load' )
exy12g= getDataSet('http://autoplot.org/data/agg/efi/$Y/po_k0_efi_$Y$m$d_v$v.cdf?BAND3',tr)
potent= getDataSet('http://autoplot.org/data/agg/efi/$Y/po_k0_efi_$Y$m$d_v$v.cdf?POTENT',tr)
espin= getDataSet('http://autoplot.org/data/agg/efi/$Y/po_k0_efi_$Y$m$d_v$v.cdf?ESPIN',tr)

if ( exy12g==None or potent==None or espin==None ):
    result= None
else:
    tt= potent.property(QDataSet.DEPEND_0)
    r= where( within( tt, dataset(DatumRangeUtil.parseTimeRange(tr)) ) )
    exy12g= exy12g[r]
    potent= potent[r]
    espin= espin[r]
    result= link(exy12g,potent,espin)