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I have imported a dataset in which the gender (m/f) has been interpreted as "binominal". If I am not mistaken, this means that there is a mapping true/false is assigned to the two values m/f.
Since I need to find association rules, this is not correct.
My question is: is it possible to convert a binominal field to nominal and then expand it again to two nominal attributes (one for male and the other for female) in order to be correctly used with the "FP-Growth" and "Create Association Rules" operators?
Nominal to Binominal operator has a "transform binominal" checkbox which does exactly that.
You don't have to transfer the binominal attribute to nominal first. It works even for binominal attributes on input.
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I am doing some programming practice and
Going through Dynamic Programming theory. we always come across two points
Optimal Substructure (OSS)
Overlapping Subproblem (OSP)
Any optimization problem with these two characteristics can be solved by using DP techniques (Memoization or Tabulation).
But we know this needs so much practice to identify the kind of problems.
Let's Say we have 4 types
TYPE 1
TYPE2
PROBLEMS
OSS
OSP
ALL DP Problem
NON-OSS
OSP
?
OSS
NON-OSP
?
NON-OSS
NON-OSP
?
e.g. Is there any problem that looks like having NON-Overlapping Subproblem but Optimal Substructure characteristics?
I need your help in listing the problem of each type. These will help me and whoever is reading this get more identifying and then solving the problem.
If you have gone through any problem (Leetcode, CodeChef, SPOJ etc) you think can be fit into '?' category please comment.
Also If you have any link/source to know more about type based on OSS/OSP.
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It might look like a simple question already answered countless times, but I could not find the optimal way(using some db).
I have a list of few thousands keywords(let's say abusive words). Whenever someone posts a message(long sentence or a paragraph), I want to check if the given sentence contains any of the keywords, so that I can block user or take other actions.
I am looking for a db/schema which can solve the above problem and gives response in a few milliseconds(<15ms).
There are many dbs which solves the reverse of the above problem: given the keywords, find documents containing keywords(text search).
Try ClickHouse for your workload.
According to docs:
multiMatchAny(...) returns 0 if none of the regular expressions are matched and 1 if any of the patterns matches. It uses hyperscan library. For patterns to search substrings in a string, it is better to use multiSearchAny since it works much faster.
The length of any of the haystack string must be less than 2^32 bytes.
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Is there a standard for varchar length relating to storing company/business names?
I have looked everywhere and cannot find an answer.
If not, what would be an ideal length to cover the majority of scenarios?
I'm going to go out on a limb here:
No
There is not in general, though there are some guidelines for some of these kinds of fields, for some organisations, in some countries (see answers to List of standard lengths for database fields).
You'll have to use best judgement. Quick google search the longest I could find was a little over 100 characters - if you're not stuck for space, throw in a few hundred to be safe, otherwise why are you strapped for space? Pull it out into a lookup table, then make the column in that table wide and move on; angsting over this will not earn you anything.
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I know my question sounds stupid but I'm curious why almost all programming languages I know uses true/false or 1/0 for boolean types.
Yes/no is meaningful than 1/0 and is shorter than true/false. Is there any logical reason why true/false is preferred?
Note that I'm not trying to convince everybody that yes/no is more appropriate, I am just curious why.
"Yes" and "no" are ambiguous. Different languages treat them differently, especially when used multiply such as a double negative. The other options lack this ambiguity.
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I was refactoring old code and encountered several IF conditions that were way too complex and long and I'm certain they can be simplified. My guess is that those conditions grew so much because of later modifications.
Anyway, I was wondering if any of you know of a good online simplifier I can use. I'm not interested in any specific language, just a simplifier that would take in for example:
((A OR B) AND (!B AND C) OR C)
And give me a simplified version of the expression, if any.
I've looked at the other similar questions but none point me to a good simplifier.
Thanks.
You can try Wolfram Alpha as in this example based on your input:
http://www.wolframalpha.com/input/?i=((A%20OR%20B)%20AND%20(NOT%20B%20AND%20C)%20OR%20C)&t=crmtb01&f=rc
Try Logic Friday 1 It includes tools from the Univerity of California (Espresso and misII) and makes them usable with a GUI. You can enter boolean equations and truth tables as desired. It also features a graphical gate diagram input and output.
The minimization can be carried out two-level or multi-level. The two-level form yields a minimized sum of products. The multi-level form creates a circuit composed out of logical gates. The types of gates can be restricted by the user.
Your expression simplifies to C.
I found that The Boolean Expression Reducer is much easier to use than Logic Friday. Plus it doesn't require installation and is multi-platform (Java).
Also in Logic Friday the expression A | B just returns 3 entries in truth table; I expected 4.