sensitivity analysis in Ocean script

In the ocean script, I need to simulate the sensitivity of ids to l
(Leff) with respect to vds, vgs and vbs. For ids table, I used
****************************************************
analysis( 'dc ?saveOppoint t ) paramAnalysis("Vb" ?start Vground ?stop -Vsupply ?step -0.1
 paramAnalysis( "Vg" ?start Vground ?stop Vsupply ?step 0.05
  paramAnalysis( "Vd" ?start Vground ?stop Vsupply ?step 0.05
 )
)
)
paramRun()

selectResults('dcOpInfo)
idsAll = pv("n1" "ids")
*****************************************************
then how to 'sens??
I checked documents, it seems 'sens is only valid for dc not paramAnalysis. do I need to sweep vb,vg and vg in the script and simulate?

Then the other problem pops out.
if I use the following script for sensitivity analysis,
****************************************************
analysis( 'sens ?analyses_list "dc" ?output_variables_list "n1:ids"
?design_parameters_list "l" )
dc( "Vg" "dc" 0.00 0.05 0.10 )
run()
selectResults('sens)
*******************************************************
then how to save and display the sensitivities with respect to vds,vgs and vbs?? I used to use pv() to save ids values with respect to terminal voltages. but in .sens, the output is "n1:ids,n1:l", then I don't know how to use pv() and whether I should use pv(). how to do that?