User guide

66 CHAPTER 3. THE LIBRARY
the negated value of a where a is a floating point number. The last four calls perform
floating point multi p l i cat i on, division, addition and subtraction on their arguments.
res := sys(Sys
flt, fl eq, a, b)
res := sys(Sys
flt, fl ne, a, b)
res := sys(Sys
flt, fl ls, a, b)
res := sys(Sys
flt, fl gr, a, b)
res := sys(Sys
flt, fl le, a, b)
res := sys(Sys
flt, fl ge, a, b) CIN:y, POS:y, NAT:y
These six calls return TRUE if the corresponding floating p oi nt comparisons are
satisfied. Otherwise the result is FALSE.
res := sys(Sys
flt, fl acos, a)
res := sys(Sys
flt, fl asin, a)
res := sys(Sys
flt, fl atan, a) CIN:y, POS:y, NAT:y
These calls return floating point appr oximations to the arc cosine, arc sine and arc
tangent of em a. The argument a is in radians and for acos the result is between 0
and π. For asin and atan it is be tween −π/2 and π/2.
res := sys(Sys flt, fl atan2, y, x) CIN:y, POS:y, NAT:y
This call re t ur n the angle in radi ans between x-axis and the line from the origin to
the point with cartesian coordinates (x, y). The result lies between −π and π.
res := sys(Sys
flt, fl cos, a)
res := sys(Sys
flt, fl sin, a)
res := sys(Sys
flt, fl tan, a) CIN:y, POS:y, NAT:y
These calls return the cosine, sine and tangent of a.
res := sys(Sys
flt, fl cosh, a)
res := sys(Sys
flt, fl sinh, a)
res := sys(Sys
flt, fl tanh, a) CIN:y, POS:y, NAT:y
These calls return the hyperbolic cosine, sine and tangent of a.
res := sys(Sys
flt, fl exp, a)
res := sys(Sys
flt, fl log, a)
res := sys(Sys
flt, fl log10, a) CIN:y, POS:y, NAT:y
The first call returns an approximation to e
a
where e is the base of natural loga-
rithms. The second call return the natural logarithm of a, and the third call returns
log to the base 10 of a.
res := sys(Sys flt, fl frexp, a)
res := sys(Sys
flt, fl ldexp, f, n) CIN:y, POS : y, NAT:y
The first call splits a floating-point number (a) into a fraction (f) and exponent
(n) such that a is approximately equal to f × 2
n
. If possible the absolute value of f
will be between 0.5 and 1.0. The call returns f and st or es n in result2. The s ec ond
call is the inverse of frexp returning an approximation to f × 2
n
.