IMO reading documentation seriously by yourself is essential for learning J. Without doing that others can't help you much.
Please also learn how to use jwiki to search for information you need, eg using the search button. On Sat, 4 Feb 2023 at 3:33 PM Ak O <akin...@gmail.com> wrote: > On Fri., Feb. 3, 2023, 04:18 bill lam, <bbill....@gmail.com> wrote: > > > Please see nuvoc foreign conjunction for detail if you don't know > anything > > about 3!:1/3!:2. > > > Which link takes me to the explanatory documentation that you are > referencing? > > > https://www.jsoftware.com/help/dictionary/d412.htm > https://code.jsoftware.com/wiki/Vocabulary/bangco > https://www.jsoftware.com/help/dictionary/dx003.htm > https://code.jsoftware.com/wiki/Vocabulary/Foreigns > > > > No, Jmf and 3!:1/3!:2 are totally different. > > > > If they are totally different, No as your response > on a programming help forum is deficient. > Respectfully. It's not easy to ask for help. > > > Ak > > > > > > > On Fri, 3 Feb 2023 at 6:04 PM Ak O <akin...@gmail.com> wrote: > > > > > I guess one of my questions directed at how the function works under > the > > > hood. > > > > > > Is it that 3!:2 is the mechanism jmf uses to treat the map? > > > How do these forms differ? > > > > > > Ak > > > > > > On Thu., Feb. 2, 2023, 22:31 Raul Miller, <rauldmil...@gmail.com> > wrote: > > > > > > > You can measure overhead with timespacex > > > > > > > > Maybe you had already been doing that? > > > > > > > > -- > > > > Raul > > > > > > > > On Thu, Feb 2, 2023 at 11:29 PM Ak O <akin...@gmail.com> wrote: > > > > > > > > > > Is this less overhead than the jmf form? > > > > > > > > > > In your example, every case where I want to operate on a file or an > > > > object > > > > > within the file requires translation through the 3!:2 operator. > > > > > > > > > > Maybe it is functionally the same as the map_jmf_ function, or am I > > > > > thinking about this incorrectly? > > > > > Or can you please explain the difference. > > > > > > > > > > Thx > > > > > > > > > > > > > > > Ak > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Thu., Feb. 2, 2023, 15:43 Don Guinn, <dongu...@gmail.com> > wrote: > > > > > > > > > > > 'testfile.txt' fwrite~3!:1 'Hello World!';(i.3 4);<2 1$'Text > > Here';1 > > > 2 > > > > 3 4 > > > > > > 456 > > > > > > > > > > > > 3!:2 fread 'testfile.txt' > > > > > > > > > > > > ┌────────────┬─────────┬───────────┐ > > > > > > > > > > > > │Hello World!│0 1 2 3│┌─────────┐│ > > > > > > > > > > > > │ │4 5 6 7││Text Here││ > > > > > > > > > > > > │ │8 9 10 11│├─────────┤│ > > > > > > > > > > > > │ │ ││1 2 3 4 ││ > > > > > > > > > > > > │ │ │└─────────┘│ > > > > > > > > > > > > └────────────┴─────────┴───────────┘ > > > > > > > > > > > > On Thu, Feb 2, 2023 at 2:19 PM Ak O <akin...@gmail.com> wrote: > > > > > > > > > > > > > In this case the data is an array of boxes. > > > > > > > The datatype is 'boxe'd. > > > > > > > The data is of some shape. > > > > > > > > > > > > > > These things have to be preserved in order to correctly restore > > > them > > > > > > > later. (at some cost, up-front to specify them, afterwards to > > > > recall > > > > > > the > > > > > > > specifics, or something else) It might be easy to write as > > literal, > > > > but > > > > > > > reverting back can present some challenges. > > > > > > > > > > > > > > For example: > > > > > > > ary=: 'abcd';4 5 6 7; 2 2 $ 8.9 7.6 .6.5 5.4 > > > > > > > > > > > > > > datatype ary > > > > > > > boxed > > > > > > > > > > > > > > datatype ":ary > > > > > > > literal > > > > > > > ***Danger*** > > > > > > > $ary NB. An array of structures that preserves > > operational > > > > > > > intention. > > > > > > > 3 > > > > > > > $":ary NB. An array whose structure is different than > its > > > > > > > operational intention. > > > > > > > 4 22 > > > > > > > > > > > > > > These are different and need to be accounted for. > > > > > > > > > > > > > > datatype (>0{ary) > > > > > > > literal > > > > > > > > > > > > > > datatype (>1{ary) > > > > > > > Integer > > > > > > > > > > > > > > datatype (>2{ary) > > > > > > > floating > > > > > > > > > > > > > > > > > > > > > Each unit has a shape and a type to preserve. > > > > > > > > > > > > > > If I want to operate on this object with the meaning intended > for > > > it > > > > when > > > > > > > it was created, many errors can be avoided when unnecessary > > > > intermediate > > > > > > > conversions are avoided. > > > > > > > > > > > > > > Jmf allows you to operate directly without having the need to > > > > > > > revert from literal to your operation/operand, datatype (with > the > > > > > > > associated overhead and tracking).I am not saying that there is > > no > > > > > > overhead > > > > > > > with jmf, just that the cognitive load is offset or preset > > because > > > > jmf > > > > > > > treats it for the user. > > > > > > > > > > > > > > > > > > > > > (1!2 & 1!:/, fwrite , fread) forms. > > > > > > > 1. Convert to literal. > > > > > > > 2. Write literal to file. > > > > > > > 3. Read literal from file. > > > > > > > 4. Convert literal type to operation type > > > > > > > 5. Operate with type. > > > > > > > End > > > > > > > ___ > > > > > > > > > > > > > > jmf form. > > > > > > > 1. Create jmf file. > > > > > > > 2. Map jmf file. > > > > > > > 3. Operate with file. > > > > > > > End > > > > > > > > > > > > > > > > > > > > > I am interested in understanding better how the best > performance > > is > > > > > > > achieved comparing these forms. > > > > > > > > > > > > > > Thoughts. > > > > > > > > > > > > > > > > > > > > > Ak > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Thu., Feb. 2, 2023, 07:51 bill lam, <bbill....@gmail.com> > > > wrote: > > > > > > > > > > > > > > > Using Jmf is overkill. Also what are the advantages of jmf > over > > > > > > 3!:1/3!:2 > > > > > > > > in this case? > > > > > > > > > > > > > > > > On Thu, 2 Feb 2023 at 7:17 PM Ak O <akin...@gmail.com> > wrote: > > > > > > > > > > > > > > > > > load 'jmf' > > > > > > > > > NB. Loads jmf facilities. > > > > > > > > > > > > > > > > > > testfile =: {2,\?50#75 > > > > > > > > > > > > > > > > > > fn =: jpath > > > > 'C:\Users\skip\J904-user\temp\foo\testfile_name.jmf' > > > > > > > > > NB. Links a covername to the file path. > > > > > > > > > createjmf_jmf_ fn;(([:(*&8)#);testfile) > > > > > > > > > NB. Create the container for your file. > > > > > > > > > NB. -fn is your reference name > > > > > > > > > NB. -(([:(*&8)#);testfile) allocates the size of yor fike > in > > > > bytes > > > > > > > > > > > > > > > > > > map_jmf_ 'testfile_disk';fn > > > > > > > > > NB. Maps the file to a noun 'testfile_disk' > > > > > > > > > ] testfile_disk_jmf_ =: testfile > > > > > > > > > > > > > > > > > > unmap_jmf 'testfile_disk_jmf_' > > > > > > > > > NB. Release mappings > > > > > > > > > Or > > > > > > > > > Exit 0 > > > > > > > > > Close session. > > > > > > > > > > > > > > > > > > > > > > > > > > > New session. > > > > > > > > > > > > > > > > > > load 'jmf' > > > > > > > > > fn =: jpath > > > > > > 'C:\Users\skip\J904-user\temp\foo\testfile_name.jmf' > > > > > > > > > map_jmf_ 'testfile1';fn > > > > > > > > > NB. Map file > > > > > > > > > ] testfile1_jmf_ > > > > > > > > > NB. File loaded as noun 'testfile1_jmf_' > > > > > > > > > > > > > > > > > > Some potential benefits of the .jmf datatype: > > > > > > > > > -Preserves header and shape information. > > > > > > > > > -If you want to map you file as read only, use the > following > > > > syntax > > > > > > > > > map_jmf_ 'testfile1';fn;'';1 > > > > > > > > > -If you would like it to be copy-on-write use the following > > > > syntax > > > > > > > > > map_jmf_ 'testfile1';fn;'';2 > > > > > > > > > > > > > > > > > > > > > > > > > > > Ak > > > > > > > > > > > > > > > > > > On Wed., Feb. 1, 2023, 21:48 'Skip Cave' via Programming, < > > > > > > > > > programm...@jsoftware.com> wrote: > > > > > > > > > > > > > > > > > > > I have a boxed noun: > > > > > > > > > > > > > > > > > > > > ] testfile =: {2,\?15#50 > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ┌────┬─────┬─────┬─────┬─────┬─────┬────┬────┬────┬────┬─────┬────┬───┬────┐ > > > > > > > > > > > > > > > > > > > > │9 21│21 47│47 37│37 13│13 33│33 20│20 4│4 49│49 6│6 > 25│25 > > > > 33│33 > > > > > > 9│9 > > > > > > > > 6│6 > > > > > > > > > > 43│ > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > └────┴─────┴─────┴─────┴─────┴─────┴────┴────┴────┴────┴─────┴────┴───┴────┘ > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > I want to store it in the following location on my > machine: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ]fn =. < 'C:\Users\skip\J904-user\temp' > > > > > > > > > > > > > > > > > > > > ┌────────────────────────────┐ > > > > > > > > > > > > > > > > > > > > │C:\Users\skip\J904-user\temp│ > > > > > > > > > > > > > > > > > > > > └────────────────────────────┘ > > > > > > > > > > > > > > > > > > > > Then I will close that J session. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Later, I will start a new J session, and I want to read > > that > > > > saved > > > > > > > file > > > > > > > > > > into a noun called 'test1' > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > What is the J code for writing the noun into a file in > the > > > > first > > > > > > > > session? > > > > > > > > > > > > > > > > > > > > What is the J code to read the file into a noun in the > > second > > > > > > > session? > > > > > > > > > > > > > > > > > > > > Should I use 1!2 & 1!:1, or fwrite & fread, or something > > > else? > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Where in the J doc are these file operations and their > > > > tradeoffs > > > > > > > > > described? > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Skip > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Skip Cave > > > > > > > > > > Cave Consulting LLC > > > > > > > > > > > > > > > > > > > > > > ---------------------------------------------------------------------- > > > > > > > > > > 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 > > > > > > > > > > > > > > > > > > > > ---------------------------------------------------------------------- > > > > > > > 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 > > > > > ---------------------------------------------------------------------- > > > > 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 > > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
