MathGroup Archive 2008

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

Search the Archive

RE: Request for Collective Wisdom...

  • To: mathgroup at
  • Subject: [mg88553] RE: [mg88463] Request for Collective Wisdom...
  • From: "Ingolf Dahl" <ingolf.dahl at>
  • Date: Thu, 8 May 2008 04:14:03 -0400 (EDT)
  • References: <>

My humble contribution to the collective wisdom:
Do not forget to tell them about how to trace errors. The simplest way is
often to put print expressions into the code: 

Print["localizing text", var]; 

to check a variable value. If you tell them about pure functions, a variant
of this theme is often useful. The expression

(Print["text ", #]; #) &@ 

can often be inserted inside expressions in appropriate places, without the
need of setting any variable value. It is a good example of the use of pure
functions and of printing as "side effect", not disturbing the computational
flow. For instance 

Sin[(Print["mytext ", #]; #) &@ Sin[2.]]

will print 

mytext 0.909297

and return


Best regards

Ingolf Dahl
ingolf.dahl at

> -----Original Message-----
> From: W_Craig Carter [mailto:wcraigcarter at] 
> Sent: den 6 maj 2008 12:38
> To: mathgroup at
> Subject: [mg88463] Request for Collective Wisdom...
> (*Below is a request for suggestions for "hints for 
> beginners. The preface is a bit long-winded" *)
> I am working on an applied math for physical scientists 
> undergraduate text---I am using Mathematica as the engine to 
> learn and solve problems quickly.
> I have an appendix that I have been creating (empirically) 
> for  a couple years: "Common Mathematica Beginners' Errors." 
> This wasn't difficult.
> I am now considering how to write another Appendix: 
> "Mathematica Usage Paradigms for Beginners."  This one is not 
> as straightforward because it will be a list of short 
> sequences of Mathematica code. The size of the list should be 
> a compromise between length, completeness, and "orthogonality."
> Some topics are obvious to (subjective) me: work symbolically 
> and with exact representations; scale to remove units when 
> possible; visualize often and when in doubt evaluate as a 
> number; pure functions are power; avoid the outdoors unless 
> you have applied the documentation, lists are your friends...
> Nota bene, this is a book for undergraduates who have just 
> received the "physics, chemistry, and multivariable calculus" 
> catechism, and
> (typically) don't appreciate that there are common themes in 
> their education (think back...).
> (* Punchline: *)
> I would sincerely appreciate thoughtful (bullet-type) 
> suggestions for paradigms.  (off-line or on- as you please).
> PS: Implicit in this is what a dear friend called "The 
> Homotopy Conjecture."  Give me a small working example, and 
> it can deformed into a complicated one for my own purposes.
> PPS: I expect a small fraction of snarky answers---I won't respond.
> --
> W. Craig Carter

  • Prev by Date: Re: Stop cell tags propagating to generated cells
  • Next by Date: Re: Trouble computing conjugates
  • Previous by thread: Request for Collective Wisdom...
  • Next by thread: Re: Request for Collective Wisdom...