Using Unicode, there is more than one valid way to represent the same letter. The characters you’re using in your Tricky Name are a “latin small letter i with circumflex” and a “latin small letter a with ring above”. You say “Note the %CC versus %C3 character representations”, but looking closer what you see are … Read more
If all the candidate keys of a relation contain multivalued attributes: Introduce a surrogate attribute for at least one multivalued attribute. For each attribute you deem “composite” (having heterogeneous components, like a tuple): For each attribute component that can be missing: Add a relation with attributes of some multivalue-free candidate key and an attribute for … Read more
norm normalizes a vector so that its sum of squares are 1. If you want to normalize the vector so that all its elements are between 0 and 1, you need to use the minimum and maximum value, which you can then use to denormalize again. %# generate some vector vec = randn(10,1); %# get … Read more
The main questions are What are you going to do with this data? and How are you filtering/sorting/joining/manipulating this data? JSON (like XML) is great for data exchange, small storage and generically defined structures, but it cannot participate in typical actions you run within your RDBMS. In most cases it will be better to transfer … Read more
You get it via SELECT LAST_INSERT_ID(); or via having your framework/MySQL library (in whatever language) call mysql_insert_id(). That won’t work. There you have to query the IDs after inserting.
Broadcasting is really good for this: row_sums = a.sum(axis=1) new_matrix = a / row_sums[:, numpy.newaxis] row_sums[:, numpy.newaxis] reshapes row_sums from being (3,) to being (3, 1). When you do a / b, a and b are broadcast against each other. You can learn more about broadcasting here or even better here.
/** * Creates a RegExp that matches the words in the search string. * Case and accent insensitive. */ function make_pattern(search_string) { // escape meta characters search_string = search_string.replace(/([|()[{.+*?^$\\])/g,”\\$1″); // split into words var words = search_string.split(/\s+/); // sort by length var length_comp = function (a,b) { return b.length – a.length; }; words.sort(length_comp); // replace … Read more
Have a look at this module: werkzeug.utils. (now in werkzeug.urls) The function you are looking for is called “url_fix” and works like this: >>> from werkzeug.urls import url_fix >>> url_fix(u’http://de.wikipedia.org/wiki/Elf (Begriffsklärung)’) ‘http://de.wikipedia.org/wiki/Elf%20%28Begriffskl%C3%A4rung%29′ It’s implemented in Werkzeug as follows: import urllib import urlparse def url_fix(s, charset=”utf-8″): “””Sometimes you get an URL by a user that just … Read more
I apologise for sounding silly as I am starting out! Do not; this is a subtle issue of great importance, which is usually (and regrettably) omitted in tutorials and introductory expositions. Unfortunately, it is not as simple as taking the square root of the inverse-transformed MSE, but it is not that complicated either; essentially what … Read more
My answer to this is the same as in an answer to your earlier question. For a probability density function, the integral over the entire space is 1. Dividing by the sum will not give you the correct density. To get the right density, you must divide by the area. To illustrate my point, try … Read more