Menu

Show posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Show posts Menu

Messages - sjain59

#1
newLISP and the O.S. / pretty-print line length
September 11, 2021, 08:51:36 PM
I am using an Intel Atom netbbok with LXLE 32 bit linux OS on ctrl-alt-F2 terminal. The screen has width of 128 characters in linux frame buffer. pretty-print gives line length 80. However when I print something it prints line to length of 128 chars. This is what I want. However there is a discrepancy between the 80 char default setting of line length and the actual line length. Perhaps this something to look into.
#2
I believe all hyperbolic functions can be computed accurately over entire range of x, given exp, log (or ln), expm1 and log1p. The x87 FPU instruction set provides exp, log, expm1 and log1p and not the hyperbolic functions. In fact the infrequently used hyperbolic functions could be removed from newLisp when expm1 and log1p (flnp1 in ANSI Forth) are present. The hyperbolic functions could easily be provided as an add on script/library.
#3
Dear Sir,



For small x << 1, ln(1+x) and exp(x)-1 and sinh(x) are close to x. This means there is loss of several digits of precision when calculating exp(x)-1 from exp(x) because we taking difference of two numbers almost equal to one another and to 1. Likewise there is similar error in ln1+x) and sinh(x) when calculated from ln(x) and exp(x) for small x.



ANSI Forth, C, and x87 FPU provide instructions expm1(x) and log1p(x) to meet this need. Once expm1 and log1p are provided, accurate computation of sinh, asinh, tanh, atanh also becomes possible for small x.



Therefore I request that expm1 and log1p be provided in newLisp.