Function for complex polynomial with variable number of arguments
- To: mathgroup at smc.vnet.net
- Subject: [mg123447] Function for complex polynomial with variable number of arguments
- From: Chris Young <cy56 at comcast.net>
- Date: Thu, 8 Dec 2011 05:21:01 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
I want to be able to pass any number of complex points to this
polynomial function and have it return the product of factors (z - p_1)
(z - p_2) etc. Works OK except when I pass in no arguments. Looks like
I have to check for this, but I'm wondering if there's a better way to
convert my arguments into factors, maybe using Fold.
poly[z_, p___] :=
Product[z - (List@p)[[i]], {1, Max[1, Length[List[p]]]}]
In[553]:= poly[x + y I, a + b I, c + d I, c + d I]
Out[553]= (-a - I b + x + I y) (-c - I d + x + I y)^2
In[554]:= poly[x + y I, a + b I]
Out[554]= -a - I b + x + I y
In[555]:= poly[x + y I, 0]
Out[555]= x + I y
In[556]:= poly[x + y I]
During evaluation of In[556]:= Part::partw : "Part 1 of {} does not
exist. â??â?¢Ë?ButtonBox["",
Appearance->{Automatic, None},
BaseStyle->"Link",
ButtonData:>"paclet:ref/message/General/partw",
ButtonNote->"Part::partw"]"
Out[556]= x + I y - {}[[1]]
- Follow-Ups:
- Re: Function for complex polynomial with variable number of arguments
- From: Heike Gramberg <heike.gramberg@gmail.com>
- Re: Function for complex polynomial with variable number of arguments