Hello Mikl;
Hello,Randy!
It seems that you're asserting that:
NEW -: foo OLD
Yes you are right. But more exactly I assert:
NEW -: pat foo OLD
I would agree, and can see what foo would be, if
NEW =: 0 1 2 3 7 8 10 11 12 13 17 18
but I don't see how you get the NEW you do get.
I dont't need values from OLD in result. I need their indexes in your
vector. And for removed items I want it to have indexes of next begger
value in your vector. It can be calculated from your vector.
RNEW =: 0 1 2 3 7 8 10 11 12 13 17 18
RIXS =: 0 1 2 3 4 5 6 7 8 9 10 11
Now it easy to see how NEW is calculated
OLD: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
IXS: 0 1 2 3 x x x 4 5 x 6 7 8 9 x x x 10 11 x
NEW: 0 1 2 3 4 4 4 4 5 6 6 7 8 9 10 10 10 10 11 12
But I can't use vector because indexes is values in diapason from 0 to
3e9. So I'm looking for numeral algorithm without making intermediate
vectors. In other words I need function that can calculate NEW for 3e9
pat foo 3e9 -: ???
--
Mikl
Please tell me what my mistake is.
------------------------------------------------------------------------
|\/| Randy A MacDonald | APL: If you can say it, it's done.. (ram)
|/\| [EMAIL PROTECTED] |
|\ | |If you cannot describe what you are doing
BSc(Math) UNBF'83 ?as a process, you don't know what you're doing.
Sapere Aude | - W. E. Deming
Natural Born APL'er | Demo website: http://156.34.69.76/
-----------------------------------------------------(INTP)----{ gnat }-
----- Original Message -----
From: "Mikl Kurkov" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, June 11, 2006 4:21 PM
Subject: [Jprogramming] Index converter
I have task for which I couldn't find a solution.
Suppose we have some indexes which relate to some data.
Now I have vector which describe which indexes to keep and which to
remove.
For example: pat =: 4 _3 2 _1
Positive value - tell how many indexes to keep, negative to remove. So
the
pat is telling that I need to keep 4 first indexes then remove 3 next,
keep another 2, remove 1, keep 4, remove 3 and so on.
I need function that for giving index give me new index after applying
such pattern. Indexes of removed items - is index of next keeped item.
So applying this function to i.20 and pat I should see:
OLD: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
NEW: 0 1 2 3 4 4 4 4 5 6 6 7 8 9 10 10 10 10 11 12
Another function will make inverse calculation - for each value from NEW
give the biggest value from OLD.
I wonder is it posible to achieve whithout precalculating vector of NEW
indexes, just by calculating new value from given pat and old index?
Thanks in advance,
Mikl
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