wolfram mathematica - Custom Notation question -

-

i need extract restrict value lists sublists, ie if vals gives values of vars={x1,x2,x3,x4}, , need values of svars={x2,x4} restrict[list,vars,svars]where

restrict[vars_, svars_, vals_] :=   extract[vals, flatten[position[vars, #] & /@ svars, 1]]

i'd improve code readability, perhaps defining following custom notation restrict[vars,svars,vals]

http://yaroslavvb.com/upload/custom-notation.png

my questions are

  1. what way implement this?
  2. is idea altogether?

good notations can useful - i'm not sure particular 1 needed...

that said, notation package makes pretty easy. there many hidden boxes when use notation palette, i'll use screenshot: alt text

you can see underlying notationmake* downvalues construct using action -> printnotationrules option. in[4] in screenshot generates

notationmakeexpression[   subscriptbox[vals_, rowbox[{vars_, "|", svars_}]], standardform] :=   makeexpression[   rowbox[{"restrict", "[", rowbox[{vars, ",", svars, ",", vals}],      "]"}], standardform]  notationmakeboxes[subscript[vals_, vars_ | svars_], standardform] :=   subscriptbox[makeboxes[vals, standardform],    rowbox[{parenthesize[vars, standardform, alternatives], "|",      parenthesize[svars, standardform, alternatives]}]]

Comments

Post a Comment

Popular posts from this blog

android - Spacing between the stars of a rating bar? -

-
ho can set spacing beween stars? thats ratingbar: ratingbar = (ratingbar) inflater.inflate(r.layout.ratingbar, null); ratingbar.setlayoutparams(new layoutparams(layoutparams.wrap_content, layoutparams.wrap_content)); the layout: <?xml version="1.0" encoding="utf-8"?> <ratingbar xmlns:android="http://schemas.android.com/apk/res/android" style="@style/mystyle" android:layout_alignparentright="true" android:layout_height="19dp" android:layout_width="wrap_content" android:numstars="5"> </ratingbar> the style: <style name="mystyle" parent="@android:style/widget.ratingbar"> <item name="android:progressdrawable">@drawable/android_r2_ratingstar_yellow</item> <item name="android:indeterminatedrawable">@drawable/android_r2_ratingstar_grey</item> </style> thanks, cheers you have ...
Read more

html - Instapaper-like algorithm -

-
does of algorithm extracts contents webpage? instapaper ? there 2 steps instapaper does: find main content block on page (excluding headers, footers, menus etc) from content block extract , format text to find content block (typically html block element, div containing key page text content) instapaper uses algorithm 1 used readability . can @ source of readability.js see what's going on, @ core tries find area on page highest text/link ratio, although has other simple scoring metrics (e.g. off top of head, things ratio of text commas, para elements etc) go heuristics. once have identified root node element, relevant content, you'll need format it, if want can pull node element containing text out of source document , insert yours, in reality you'll want remove existing styles , apply own, standard , feel. if want output nice text-only can use jericho's renderer . update1 : should mention else instapaper - follow 'pagination' links (...
Read more

c# - How to execute a particular part of code asynchronously in a class -

-
i creating speech recognition engine that's going respond user commands.i have created button enable , disable speech recognition per user convenience.i have used dispose() of speech engine disable speech recoginition.here code private void button1_click(object sender, routedeventargs e) { engineon = !engineon; if (engineon) { speechengine = speech.createspeechengine(); //speech class creates , returns new speech engine. speechengine.audiolevelupdated += new eventhandler<audiolevelupdatedeventargs>(speechengine_audiolevelupdated); // use system's default microphone speechengine.setinputtodefaultaudiodevice(); speechengine.loadgrammar(new dictationgrammar()); // start listening speechengine.recognizeasync(recognizemode.multiple); } else { speechclass.myengine.dispose(); } } but disposal of speech obj...
Read more