Tetration Forum
PARI/gp - Printable Version

+- Tetration Forum (http://math.eretrandre.org/tetrationforum)
+-- Forum: Tetration and Related Topics (http://math.eretrandre.org/tetrationforum/forumdisplay.php?fid=1)
+--- Forum: Computation (http://math.eretrandre.org/tetrationforum/forumdisplay.php?fid=8)
+--- Thread: PARI/gp (/showthread.php?tid=1166)

Pages: 1 2


PARI/gp - Xorter - 04/17/2017

Hi, again!
I need your help in PARI/gp. I would like to substitute a value into x of sin(x):
Code:
subst(sin(x),x,1)
But it returns with error. Why? Please, help me.


RE: PARI/gp - Gottfried - 04/17/2017

(04/17/2017, 09:48 AM)Xorter Wrote: Hi, again!
I need your help in PARI/gp. I would like to substitute a value into x of sin(x):
Code:
subst(sin(x),x,1)
But it returns with error. Why? Please, help me.

Code:
subst(Pol(sin(x)),x,1)
should work. But why not simply do
Code:
sin(1)
?


RE: PARI/gp - Xorter - 04/17/2017

(04/17/2017, 04:27 PM)Gottfried Wrote:
(04/17/2017, 09:48 AM)Xorter Wrote: Hi, again!
I need your help in PARI/gp. I would like to substitute a value into x of sin(x):
Code:
subst(sin(x),x,1)
But it returns with error. Why? Please, help me.

Code:
subst(Pol(sin(x)),x,1)
should work. But why not simply do
Code:
sin(1)
?

Oh, it was simplier than I thought. Thank you, my friend!
Well, because I have found a new type of integration and derivation. These are iterated! And I needed substitution in a function in my gp. Really amazing. I am going to share my results on this forum as soon as possibly.
(May be the key to determine what between addition and multiplication is.)
Just wait a few days, please.


RE: PARI/gp - Xorter - 04/17/2017

But somewhy it does not work with gamma function. Sad


RE: PARI/gp - sheldonison - 04/18/2017

(04/17/2017, 07:05 PM)Xorter Wrote: But somewhy it does not work with gamma function. Sad

sin(x+1) or gamma(x+1)


RE: PARI/gp - Xorter - 04/18/2017

(04/18/2017, 05:37 AM)sheldonison Wrote:
(04/17/2017, 07:05 PM)Xorter Wrote: But somewhy it does not work with gamma function. Sad

sin(x+1) or gamma(x+1)

I have determined the graphs with sin functions, but now I would like to work with gamma, too.
These methods are the generalizations of the integration and derivation...


RE: PARI/gp - Xorter - 11/20/2017

Hi, again!

Here is another problem. I would like to calculate this productum but without success:
Code:
subst(exp(1/x),x,1/1000)
Why?


RE: PARI/gp - Gottfried - 11/21/2017

(11/20/2017, 08:21 PM)Xorter Wrote: Hi, again!

Here is another problem. I would like to calculate this productum but without success:
Code:
subst(exp(1/x),x,1/1000)
Why?

The error message in my (old) Pari/GP-system is                          


Quote:exp(1/'x)
   *** exp: negative exponent in gexp.


I don't think they have anything new implemented for this problem so far.


RE: PARI/gp - Xorter - 11/21/2017

I got the following error message:

  ***   at top-level: subst(exp(1/x),x,1/1000)

  ***                       ^------------------
  *** exp: domain error in exp: valuation < 0

My question is that how can we solve this problem?


RE: PARI/gp - Gottfried - 11/21/2017

(11/21/2017, 01:31 PM)Xorter Wrote: I got the following error message:

  ***   at top-level: subst(exp(1/x),x,1/1000)

  ***                       ^------------------
  *** exp: domain error in exp: valuation < 0

My question is that how can we solve this problem?

Perhaps it is meaningful for you to replace 1/x by exp(-u) where u=log(x) ? At least this gives a power series (more precisiely a puisieux-series)