[Date Index] [Thread Index] [Author Index]

Re: evaluating functions and displaying results numerically

• To: mathgroup at smc.vnet.net
• Subject: [mg126170] Re: evaluating functions and displaying results numerically
• From: "Kevin J. McCann" <kjm at KevinMcCann.com>
• Date: Sun, 22 Apr 2012 06:08:25 -0400 (EDT)
• Delivered-to: l-mathgroup@mail-archive0.wolfram.com
• References: <jmtdec$sjd$1@smc.vnet.net>

The output Sin[1] is what is called an "exact", i.e. you gave Mathematica an 
exact input 1, not 1.0; so, Mathematica returned an exact. If you want a 
function to give a numerical, i.e. machine precision output, do 
something like this:

Sin[1]//N

or

N[Sin[1]]

That is, wrap the result in N[], the number function.

Cheers,

Kevin

On 4/21/2012 12:35 AM, Eduardo Fontana wrote:
> Once in a while a face a problem with Mathematica in which I cannot
> get a straightforward numerical output.
> I have a function defined in mathematica, I try to evaluate the
> function with numerical arguments and mathematica returns a replica of
> my function with the same arguments. It must be something I set
> without noticing. I cannot get numerical results at all.
> In another instance, I have a summation of about 1000 terms defined as
> a function of 3 arguments. When I use numerical arguments, instead of
> Mathematica calculating a numerical result it generates a symbolic
> output with all 1000 terms. Even if a try something very simple such
> as
> In[1]: Sin[1]
> the output is
> Out[1]: Sin[1]
> Could anyone give me a clue on this?
> regards
>