That use of 'pages' was fairly common among the APL programmers I knew in the mid-70s, and I have a feeling that it was used in some introductory material from STSC or IPSA.
Romilly On 7 September 2012 14:45, Raul Miller <[email protected]> wrote: > I do not recall using this word this way, for whatever that is worth... > > -- > Raul > > On Fri, Sep 7, 2012 at 4:03 AM, Linda Alvord <[email protected]> > wrote: > > Did you happen to notice David's use of the word "pages" at the end of > his > > message? It makes a great visual image to explain the array. > > > > I was wondering if it has been used in this context before, or does it > have > > a long and checkered APL or J history? > > > > Linda > > > > > > -----Original Message----- > > From: [email protected] > > [mailto:[email protected]] On Behalf Of David > Ward > > Lambert > > Sent: Wednesday, September 05, 2012 9:57 PM > > To: programming > > Subject: Re: [Jprogramming] duplicate row of matrix > > > > Right! "Matrix multiplication" usually means something else. > > You want a sort of element-by-corresponding-element multiplication. > > > > B ; A > > +-------+-------+ > > |1 1 0 0|1 1 1 1| > > |0 0 1 1|1 1 2 2| > > | |1 1 3 3| > > | |1 1 4 4| > > +-------+-------+ > > > > A solution uses rank conjunction twice. I couldn't begin to understand > it > > the first time I saw this sort of construction. Then one day I wrote > rank > > rank and retrospectively realized what I'd written and understood. > > I practiced rank with sentences like 'abc' "2 i. 2 3 4 > > > > My thoughts to construct this sentence: > > First I realized that you need to multiply row by row. > > The ("1) adverb ensures this. The frames of these two matrices disagree > > because there are 2 rows in B and 4 in A. The next adverb ("_ 1) means > > (because ultimately the final verb is dyadic) "use all of the left array > > with each row of the right hand array". > > > > B * ("1) ("_ 1) A > > 1 1 0 0 > > 0 0 1 1 > > > > 1 1 0 0 > > 0 0 2 2 > > > > 1 1 0 0 > > 0 0 3 3 > > > > 1 1 0 0 > > 0 0 4 4 > > > > Finally, inserting append between the pages gives > > > > ,/B*"1"_ 1 A > > 1 1 0 0 > > 0 0 1 1 > > 1 1 0 0 > > 0 0 2 2 > > 1 1 0 0 > > 0 0 3 3 > > 1 1 0 0 > > 0 0 4 4 > > > > > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > -- http://quick2wire.com enhance your Raspberry Pi ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
