[R] Tool for solving equations

[David Winsemius]

On Sep 28, 2009, at 8:49 PM, David Winsemius wrote:

>
> On Sep 28, 2009, at 6:22 PM, Dmitry Gospodaryov wrote:
>
>> Does exist any tool in R to solve equations, especially complex  
>> exponential equations?
>> For example:
>> y = 100*exp(b*(1-exp(c*x))/c)

If you plot that function, you see that it is asymptotically zero in  
its positive domain:

 > b=10; c=1
 > plot(-10:10, 100*exp(b*(1-exp(c*(-10:10)))/c))
 >  100*exp(b*(1-exp(c*(-10:10)))/c)
  [1]  2.201647e+06  2.199930e+06  2.195270e+06  2.182652e+06   
2.148720e+06  2.059123e+06
  [7]  1.834007e+06  1.338820e+06  5.691034e+05  5.562432e+04   
1.000000e+02  3.448235e-06
[13]  1.789295e-26  1.295885e-81 1.683418e-231  0.000000e+00  0.000000e 
+00  0.000000e+00
[19]  0.000000e+00  0.000000e+00  0.000000e+00

... So that raises the question of what you are really trying to  
accomplish.

>> If it is so, then what is the package i have to
>> use and what is algorythm for this solving?
>> Thank you for advance.
>> With regard, Dmitry.


-- 
David Winsemius, MD
Heritage Laboratories
West Hartford, CT