Scaled modified Bessel function of the first kind, order one.
Loading LOADSUB ALL FROM "BESMC.HTS"
or LOADSUB FROM "MATHLIB.HTS"
Usage REAL X,Y
Y=FNI1e(X)
Description
FNI1ereturns the value of the modified cylindrical Bessel function of the first kind and order one ofxscaled bye-|x|,e-|x|I1(x). The scaling is done so that the value ofI1(x) can be evaluated for arguments of large absolute value, where the absolute value ofI1(x) may be larger than MAXREAL, the largest value representable. The absolute value ofe-|x|I1(x) is moderate for arguments of large absolute value.
Errors
FNI1ecauses an HTBasic error if its argument is not of type REAL.