encounte里report timing后报出的density指的是什么

急求！

Use the queryDensityInBox command to get the density for a specific area in the design.
It is recommended that you use the queryPlaceDensity command for reporting the standard cell utilization. The standard cell utilization reported by the queryPlaceDensity command is calculated as:
( stdcell_area + block_area ) / alloc_area
where,
stdcell_area = area_of_standard_cells + area_of_physical_cells (filler, Endcap, welltaps, power shutoff (PSO) and Decaps cells)
block_area = area of the placed and unplaced blocks
alloc_area = total_area_of_sites - area_of_blocked_sites
Note: The area of placed and unplaced blocks is zero if blocks are marked as FIXED . The FIXED blocks are not included in the calculation. The queryPlaceDensity command lists the block area if blocks are included in the standard cell utilization calculation.
Note: The following commands calculate the standard cell utilization using the same equation as queryPlaceDensity :
checkPlace and checkDesign -place
placeDesign
timeDesign and optDesign (Does not use cell padding in the calculation for standard cell utilization)
summaryReport
dbFPlanRegRowDensity
queryDensityInBox

解释很专业， 赞一个，

把DOC上的东西搬运一下而已。有些人不是懒么?哈哈哈