[Main]
Name=CkValidDelta
Type=Function
Subtype=ROM Call
Header Files=graphing.h
Definition=unsigned char CkValidDelta (float maxrng, float minrng, float delta);
See Also=StepCk

[ROM Call]
Index=$1C3

[Description]
Checks the validity of a given delta.

[Explanation]
CkValidDelta checks to see if the exponent of <I>delta</I> is too small relative to the exponents
of <I>maxrng</I> and <I>minrng</I> so that all the significant digits of delta would be
shifted out of the floating-point mantissa when performing arithmetic.
<BR><BR>
The parameter <I>maxrng</I> is the final value in the graph window variable sequence (e.g., xmax,
ymax, tmax, etc.). The parameter <I>minrng</I> is the first value in the graph window variable sequence (e.g., xmin,
ymin, tmin, etc.). The parameter <I>delta</I> is the increment value which will be used to compute the sequence from
<I>minrng</I> to <I>maxrng</I> (e.g., &#916;x, &#916;y, tstep, etc.).
<BR><BR>
CkValidDelta returns 1 if delta is valid, 0 if the exponent of delta is too small.
<BR><BR>
<B>Note:</B> CkValidDelta assumes the sign of delta has already been verified as correct for
computing a sequence from minrng to maxrng. It is valid for maxrng to be
less than minrng if delta is negative.

[References]
In=CptDeltax, StepCk, bascmd.h/cmd_drawinv
Out=unknown.h/_bcd_math
