Program sfmaskval | Mask values inside or outside of a range.
[SYNOPSIS]
sfmaskval < in.rsf > out.rsf upper=+FLT_MAX lower=-FLT_MAX upperval=+FLT_MAX lowerval=-FLT_MAX
[COMMENTS]

sfmaskval < in.rsf > out.rsf upper=ul lower=ll upperval=uv lowerval=lv

If upper > lower, then values larger than ul will be changed to uv and
values belowe ll will be changed to lv.
If upper < lower, then values inside [ul;ll] will be changed to lv.


[PARAMETERS]
float   | lower | =-FLT_MAX |   | 	lower range limit 
float   | lowerval | =-FLT_MAX |   | 	lower range value 
float   | upper | =+FLT_MAX |   | 	upper range limit 
float   | upperval | =+FLT_MAX |   | 	upper range value 
[DIRECTORY]
user/bash
