The following PDFFIT specific functions exist. For a listing of general intrinsic functions see help entry 'functions' in the 'command language' section of the online help.
bang(u1,u2,u3,v1,v2,v3[,w1,w2,w3]) :
Returns the bond angle at the site v. If only vectors u and v
are given, the angle between u and v is returned.
blen(u1,u2,u3[,v1,v2,v3]) :
Returns the length of vector v-u. Vector v defaults to zero.
dstar(h1,h2,h2[,k1,k2,k3]) :
Returns the length of reciprocal vector k-h. Vector k defaults
to zero.
rang(h1,h2,h3,k1,k2,k3[,l1,l2,l3]) :
Returns the angle between vectors k-h and k-l at reciprocal site k.
If l is omitted, the angle between the reciprocal vectors h and k
is returned.
gran(val,typ) :
Returns Gaussian distributed pseudo random number with mean zero
an a width given by parameter <val>. If <typ> is "s" <val> is taken
as sigma, if <typ> is "f", <val> is taken as FWHM.
gbox(r1,r2,r3) :
Returns pseudo random number with distribution given by a box
centered at 0 with a width of <r2> and two half Gaussian
distributions with individual sigmas of <r1> and <r3> to the
left and right, respectively.
rval(s [,rmin,rmax])
Returns the weighted R-value corresponding to data set <s>.
The optional parameters allow the user to calculate the R-value
for a specific region in r.