search for: tanpi

As the subject line says, we get different results for tan(pi/2) and tanpi(1/2), though this should not be the case: > tan(pi/2) [1] 1.633124e+16 > tanpi(1/2) [1] NaN Warning message: In tanpi(1/2) : NaNs produced By redefining tanpi with sinpi and cospi, we can get closer: > tanpi <- function(x) sinpi(x) / cospi(x) > ta...

The same argument would hold for tan(pi/2). I don't say the result 'NaN' is wrong, but I thought, tan(pi*x) and tanpi(x) should give the same result. Hans Werner On Fri, Sep 9, 2016 at 8:44 PM, William Dunlap <wdunlap at tibco.com> wrote: > It should be the case that tan(pi*x) != tanpi(x) in many cases - that is why > it was added. The limits from below and below of the real function > tan(pi*x)...

...are many specific functions for calculating in those regions. On Fri, Sep 9, 2016 at 12:55 PM, Hans W Borchers <hwborchers at gmail.com> wrote: > The same argument would hold for tan(pi/2). > I don't say the result 'NaN' is wrong, > but I thought, > tan(pi*x) and tanpi(x) should give the same result. > > Hans Werner > > > On Fri, Sep 9, 2016 at 8:44 PM, William Dunlap <wdunlap at tibco.com> wrote: >> It should be the case that tan(pi*x) != tanpi(x) in many cases - that is why >> it was added. The limits from below and below of th...

...>> i try sin, cos, and tan. >> >> >>> sapply(c(cos,sin,tan),function(x,y)x(y),1.23e45*pi) >> >> [1] 0.5444181 0.8388140 1.5407532 >> >> >> However, *pi results the following >> >> >>> sapply(c(cospi,sinpi,tanpi),function(x,y)x(y),1.23e45) >> >> [1] 1 0 0 >> >> >> Please try whether the following becomes all right. >> >> > [..............................] >> >> > Yes, it does -- the fix will be in all future versions of R. >&gt...

Hi, i try sin, cos, and tan. > sapply(c(cos,sin,tan),function(x,y)x(y),1.23e45*pi) [1] 0.5444181 0.8388140 1.5407532 However, *pi results the following > sapply(c(cospi,sinpi,tanpi),function(x,y)x(y),1.23e45) [1] 1 0 0 Please try whether the following becomes all right. diff -ruN R-3.3.2.orig/src/nmath/cospi.c R-3.3.2/src/nmath/cospi.c --- R-3.3.2.orig/src/nmath/cospi.c 2016-09-15 07:15:31.000000000 +0900 +++ R-3.3.2/src/nmath/cospi.c 2016-12-01 13:54:38.863357149 +0...

...t; >> Hi, > >> i try sin, cos, and tan. > > >>> sapply(c(cos,sin,tan),function(x,y)x(y),1.23e45*pi) > >> [1] 0.5444181 0.8388140 1.5407532 > > >> However, *pi results the following > > >>> sapply(c(cospi,sinpi,tanpi),function(x,y)x(y),1.23e45) > >> [1] 1 0 0 > > >> Please try whether the following becomes all right. > > > [..............................] > > > Yes, it does -- the fix will be in all future versions of R. > > oops.... not so quickly,...

...Thu, 1 Dec 2016 14:39:55 +0900 writes: >> Hi, >> i try sin, cos, and tan. >>> sapply(c(cos,sin,tan),function(x,y)x(y),1.23e45*pi) >> [1] 0.5444181 0.8388140 1.5407532 >> However, *pi results the following >>> sapply(c(cospi,sinpi,tanpi),function(x,y)x(y),1.23e45) >> [1] 1 0 0 >> Please try whether the following becomes all right. > [..............................] > Yes, it does -- the fix will be in all future versions of R. oops.... not so quickly, Martin! Of course, the results then coin...

...ter but less flexible, since that table is programmed in C. It would be useful if R provided a mechanism for extending the derivative table, or barring that, provided a broader table. Currently unsupported mathematical functions of one argument include expm1, log1p, log2, log10, cospi, sinpi, and tanpi. While manual differentiation of these proposed additions is straight-forward, their absence complicates what otherwise could be much simpler, such as using deriv() or deriv3() to generate functions, for example to use as an nls model. Thanks, [[alternative HTML version deleted]]

...), cospi = make.call("*", make.call("*", make.call("sinpi", expr[[2]]), make.call("-", D(expr[[2]], name))), quote(pi)), sinpi = make.call("*", make.call("*", make.call("cospi", expr[[2]]), D(expr[[2]], name)), quote(pi)), tanpi = make.call("/", make.call("*", D(expr[[2]], name), quote(pi)), make.call("^", make.call("cospi", expr[[2]]), 2)), Jerry From: Avraham Adler [mailto:avraham.adler at gmail.com] Sent: Friday, February 17, 2017 4:16 PM To: Jerry Lewis; r-devel at r-project.or...

...exible, since that table is programmed in C. It would be useful if R > provided a mechanism for extending the derivative table, or barring that, > provided a broader table. Currently unsupported mathematical functions of > one argument include expm1, log1p, log2, log10, cospi, sinpi, and tanpi. > > While manual differentiation of these proposed additions is > straight-forward, their absence complicates what otherwise could be much > simpler, such as using deriv() or deriv3() to generate functions, for > example to use as an nls model. > > Thanks, > > [[...