SUOP - do unary arithmetic operation on segys

suop <stdin >stdout op=abs

Required parameters:
none

Optional parameter:
op=abs operation flag
abs : absolute value
ssqrt : signed square root
sqr : square
ssqr : signed square
sgn : signum function
exp : exponentiate
slog : signed natural log
slog10: signed common log
cos : cosine
sin : sine
tan : tangent
cosh : hyperbolic cosine
sinh : hyperbolic sine
tanh : hyperbolic tangent
norm : divide trace by Max. Value
db : 20 * slog10 (data)
neg : negate value
posonly : pass only positive values
negonly : pass only negative values
nop : no operation

Note: Binary ops are provided by suop2.
Operations slog and slog10 are "punctuated", meaning that if
the input contains 0 values, 0 values are returned.


Credits:

CWP: Shuki, Jack
Toralf Foerster: norm and db operations, 10/95.

Notes:
If efficiency becomes important consider inverting main loop
and repeating operation code within the branches of the switch.

Note on db option. The following are equivalent:
... | sufft | suamp | suop op=norm | suop op=slog10 |\
sugain scale=20| suxgraph style=normal

... | sufft | suamp | suop op=db | suxgraph style=normal