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Re: [OT] was: Where is NSList? (All Threads)
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Re: [OT] was: Where is NSList? (All Threads)


  • Subject: Re: [OT] was: Where is NSList? (All Threads)
  • From: "Keith J.Schultz" <email@hidden>
  • Date: Fri, 30 Jul 2004 10:33:19 +0200

Hi Everybody,

I think you should all go back to school and take a software engineering course.
Your statements are correct to a single respect which you point out.

A very good programmer will first:
1) analyse his data structures and required methods (procedures)
2) available languages and resources
3) intended distribution (effects choices in 2)
4) time table for development

OO-programming languages are neat and make development quick and easy, yet it
comes with perfomance hits !! It has many times been mentioned here about the
efficiency of different algorithms, but you have missed out one how the objects
are implemented in Cocoa. You have discussed how one can make programs more efficient
you you start with this and then make it better by that, but a good programmer will have
actually considered the the best method a head of time. S/he should only need to reconsider
if the specifictions change.

As a rule if you need something to be efficient code it you self !

An example:
a matrix(array) where a[i,j] = a[j,i]
a new matrix had be calcuted by a very complicated formula where rows and columns mutiplied
and diffent sums where used.

--> you can reduce the size of the matrix by considering to be diagonal, by a factor of roughly 2
--> now with working knowlege of C and how C accesses arrays one could simply use nested loops
and do the calcutions. But there is a faster way the basic algorithm is the same but instead
of use arrays, one could access the values via pointers. The effect is dramatic. The program
ran a 1000 times faster. This optimaztion of an programme which was programmed straight forward
was done by analysis of the problem not the program.

My advice is there think first code later.

Good programming is:

20 % analysis and planning
10 % coding
60 % documentation

my two Euro cents worth.
Keith. _______________________________________________
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    • Re: [OT] was: Where is NSList? (All Threads)
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    • [Moderator] Re: [OT] was: Where is NSList? (All Threads)
      • From: mmalcolm crawford <email@hidden>
    • Re: [OT] was: Where is NSList? (All Threads)
      • From: Steve Bird <email@hidden>
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References: 
 >Where is NSList? (From: Tim Conkling <email@hidden>)
 >Re: Where is NSList? (From: Shawn Erickson <email@hidden>)
 >Re: Where is NSList? (From: Tim Conkling <email@hidden>)
 >Re: Where is NSList? (From: Steve Checkoway <email@hidden>)
 >Re: Where is NSList? (From: Tim Conkling <email@hidden>)
 >Re: Where is NSList? (From: Dustin Voss <email@hidden>)
 >Re: Where is NSList? (From: Steve Checkoway <email@hidden>)
 >Re: Where is NSList? (From: Pandaa <email@hidden>)
 >Re: Where is NSList? (From: Steve Checkoway <email@hidden>)
 >[OT] Premature optimizations (was: Where is NSList?) (From: Allan Odgaard <email@hidden>)

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