Re: Mathematica 9--Is This A Joke?

*To*: mathgroup at smc.vnet.net*Subject*: [mg128889] Re: Mathematica 9--Is This A Joke?*From*: Bill Rowe <readnews at sbcglobal.net>*Date*: Sun, 2 Dec 2012 05:00:21 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-newout@smc.vnet.net*Delivered-to*: mathgroup-newsend@smc.vnet.net

On 12/1/12 at 4:32 AM, jiyajbe at gmail.com (Kevin Wheelock) wrote: >Yes, I read the docs after one of my existing documents failed. >(Naively, I initially assumed my docs created in version 8 would >work in version 9...Nope.) >And, your description of how to get units points to my comment about >Usability Testing. In what universe is typing >M := Quantity[ (okay, hold on, let's find out what the unit is; >Control+= 1 Newton --> Wolfram|Alpha, <wait...> Okay, it's >"Newtons", not "Newton") 10, "Newtons"] >better than typing >M := 10 Newtons? >It takes ten times as long, and the resulting code is far less >readable. I agree the new system will take a bit of time/usage before I adapt to it. I also agree it seems more effort to type m = Quantity[...] than m = 10 Meter. But I do see the new system as an improvement in several ways. The old system was fragile. Units where undefined symbols. If at some point a value got assigned to the unit symbol, there would be problems with computations that likely would be difficult to track. Additionally, there was no robust way to separate the symbols representing units from symbols representing variables. Consider: With version 8 and the Units package: In[2]:= a = 10 Meter; b = x Meter; In[4]:= First[a] Out[4]= 10 In[5]:= First[b] Out[5]= Meter With version 9: In[1]:= a = Quantity[10, "Meters"]; b = Quantity[x, "Meters"]; In[3]:= First[a] Out[3]= 10 In[4]:= First[b] Out[4]= x