Use of erf(x); read text file; command to display available functions
Subject: Use of erf(x); read text file; command to display available functions
From: Barton Willis
Date: Tue, 14 Aug 2007 08:12:34 -0500
-----maxima-bounces at math.utexas.edu wrote: -----
>Why doesn't erf(5) produce a numerical result, whereas
>sin(.3) or gamma(.2) do?
Because Maxima returns a floating point approximation to
most functions only when the function receives a floating
input or the option variable 'numer' is true; for example
(%i4) erf(5.0);
(%o4) 0.99999999999846
(%i5) numer : true$
(%i6) erf(5);
(%o6) 0.99999999999846
(%i7) numer : false$
(%i8) erf(5);
(%o8) erf(5)
>--------------------
>
>Can Maxima read a text file containing a column of
>numbers?
>
Yes, at a Maxima command line, try this
(%o2) ? read_matrix
Maxima should show you the user documentation for
'read_matrix' Maybe 'read_matrix' will do what you want.
>Is there a function to display available functions -
>not just those defined by a user?
>
Oh, not really. But if you can guess the function name, try entering
a question mark followed by your guess; for example
(%o3) ? erf
If you don't find what you are looking for and you are using wxMaxima,
you'll get a dialog box that will allow you to search the user
documentation.
Maybe this helps -- let us know if you have more questions.
Barton