Just an update on the visualization of J results. I have done a second video/blog post on using CSS and HTML to display results on JHS. It provides examples of a system that allows you to distinguish between 1 $ 1 , 1 1 $1 , and 1 as well as displaying arrays with zeros in the shape such as 0 1 $ 1 and 1 0 $ 1.
Blog post is here: http://bobtherriault.wordpress.com/2014/02/11/using-css-and-html-to-display-the-shapes-of-arrays-on-the-jhs-platform/?relatedposts_exclude=513 Cheers, bob On Feb 4, 2014, at 8:25 AM, robert therriault <bobtherria...@mac.com> wrote: > > On Feb 4, 2014, at 5:29 AM, Raul Miller <rauldmil...@gmail.com> wrote: > >> >> Of course you will also get an error if you try to combine one of >> those with another array of the wrong shape. Error conditions are one >> of the cases where I like getting the shapes of arrays. >> > > Sometimes the zeros can affect the result even though they can't be seen in > the display > > $ ( 0 2 3 $ 4), 5 7 $5 > 1 5 7 > $ (0 0 2 3 $ 4), 5 7 $5 > 1 1 5 7 > > I am looking for ways to give the programmer some 'leverage' into these > situations by the ways that shapes are displayed > >> One of my favorite tricks, if I am getting an error from an expression >> that seems to be due to of a lack of shapeliness (like a length error) >> is to replace the last verb with $ (or a variation like ;&$ or $&.> or >> ;&($ L:0) or whatever else). >> >> And that brings up another issue related to finding the shapes of >> things: the shape inside a box will typically be different from the >> shape outside the box (these shapes are "independent" of each other). > > Yep, I am working on boxes at the moment and it is a challenge for display > while retaining the independent shape of contents. > >> Also, the shape of transitory arrays (intermediate results) can also >> matter. So familiarity with debugging tools and techniques can be >> crucial - sometimes even more important for coding than familiarity >> with shape and rank issues. (These are not, properly speaking, a part >> of the language itself so much as they are a part of the environment. >> But that's something of a technicality.) > > No doubt. Display can't replace knowing how rank and shape work. I am hoping > that a little better way of displaying results will make it easier to see the > differences and may emphasize the importance of understanding the concepts to > those learning the language - that would be me! > > Cheers, bob > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
