Re: Q: Thread behaviour
- To: mathgroup at smc.vnet.net
- Subject: [mg57954] Re: [mg57933] Q: Thread behaviour
- From: Andrzej Kozlowski <andrzej at akikoz.net>
- Date: Tue, 14 Jun 2005 05:10:19 -0400 (EDT)
- References: <200506130950.FAA29336@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
On 13 Jun 2005, at 18:50, Dick Barends wrote: > Hallo, > > k[x_,y_] = x^2+y^2 > Thread[k[a+b,c d],Plus] > gives: (a+b)^2+c^2 d^2 > I would expect: a^2 + (c d)^2 + b^2 + (c d)^2 (See below) > > ----------------- > When I use: > Thread[m[a+b, c d],Plus] > gives: m[a, c d] + m[b, c d] > This is what should happen. > > What gives "m" a different solution than "k"???? > > I hoop some of you will answer:-) > > greetings > Dick > > Compare In[39]:= Thread[k[a + b, c*d], Plus] (a + b)^2 + c^2*d^2 with Thread[Unevaluated[k[a + b, c*d]], Plus] a^2 + b^2 + 2*c^2*d^2 Alternatively, give k the attribute HoldAll SetAttributes[k, HoldAll] Thread[k[a + b, c*d], Plus] (a + b)^2 + c^2*d^2 Andrzej Kozlowski Chiba, Japan
- References:
- Q: Thread behaviour
- From: Dick Barends <dick.barends@wxs.nl>
- Q: Thread behaviour