# The Local Maximum Search Module

This module allows to search for local maxima in two-dimensional datasets stored within a SICS histogram memory. All commands act upon the current content of the histogram memory. The following commands are understood:

lowmax stat hm
  calculates the average and the maximum count in the frame currently held in histogram memory hm.
lowmax search hm
  searches the frame held in histogram memory hm for local maxima. Local maxima are returned as sets of three numbers which are the x and y coordinates and the intensity. Each set of numbers is separated from the next one by the @ symbol.
lowmax cog hm x y
  calculates the center ogf gravity for the pixel at coordinates x and y in histogram memory hm. Four numbers are returned: the new x and y coordinates, the intensity of the peak and the number of points contributing to the peak.
lowmax steepness val
  accesses the steepness parameter for the peak search. With a parameter val sets a new value, without print the current value.
lowmax window val
  accesses the window parameter for the peak search. With a parameter val sets a new value, without print the current value.
lowmax threshold val
  accesses the thresholds parameter for the peak search. With a parameter val sets a new value, without print the current value.
lowmax cogwindow val
  accesses the cogwindow parameter for the peak search. With a parameter val sets a new value, without print the current value.
lowmax cogcontour val
  accesses the cogcontour parameter for the peak search. With a parameter val sets a new value, without print the current value.

The local maximum search can be tuned through the parameters: The window parameter sets the size of the quadratic area for which a candidate pixel must be the local maximum. Threshold sets a minimum count rate for a local maximum. Steepness sets a minimum difference to the borders of the window used for the local maximum search which must be fulfilled.

The center of gravity calculation can be tuned mainly through the cogcontour parameter which determines at which percentage of the maximum value of the peak the center of gravity calculation stops. Cogwindow is the size of the area in which a center of gravity is calculated. Can be set rather generously.