When the slope cannot be reliably determined it is set to a default value of 0.0.
As the slope is an average value it is only useful when the orders are fairly consistent. In highly distorted frames it may be useful to set the slope manually prior to tracing a particularly wild order. To set the slope use FIGARO SETOBJ
SETOBJ object=/rdctn-file-name/.MORE.ECHELLE.ORDER_SLOPE value=n.nnn
at the system command prompt.
Martin Clayton