With respect to Information Retrieval,
I fairly understood the concepts of inverted indices/files. Got to know that signature file was compared much inverted file. But I dont understand concept behind the Signature file concept ?
Could anybody explain the difference or point out where i can read about it ?
I found a good explaination on page 6 of this paper. Currently, I am not convinced of an advantage of signature files over an inverted index.
Related
I'm working on a creating a genetic algorithm for a class project in python. The algorithm works perfectly, but I want to create an image of the tree, rather than just a simple text output. I have written a function that performs well for trees up to about 4 levels. Above that, the display doesn't work well, and there ends up with too much blank space. I know why, but it might take me too long to come up with a better solution.
Does anyone know if there exists a function to create a compact non-binary tree display? I'm looking for one that adjusts each branch so there isn't a ton of blank space between them, given that a lot of the branch depths are un-even. I've found a lot of binary tree display functions, but that doesn't work because some of my nodes have 3 children.
You can see it working well and not working well in the images.
Decent looking tree:
https://drive.google.com/file/d/1j2BQjanTDgvzttedUyhxnbWhkXuQwyaG/view?usp=sharing
Not so great tree (too much blank space):
https://drive.google.com/file/d/1Gh90e3JvAeCB_U2NhvvouZulM4CVQ8ZH/view?usp=sharing
Thanks in advance.
Use graphviz.
In particular, the dot layout generator should be a good match for your needs.
You may also find the NetworkX drawing module helpful.
I am trying to understand what the raw data from an audio file looks like and how to get that data. I want to take the data and analyze it and see if I am able to make a program that can recognize patterns in a song such as in a hip hop song, finding the same beat in a chorus. In my head I think this could be a doable task if the data is in an integer form.
I've looked up many tutorials for this but all the tutorials use other libraries or don't explain it in a way I understand(more than likely the source of my issue).
I am wondering if there is someone out there that can help me understand a few things.
1). In an MP3 file, what is actually being stored in the file. Is it an integer that tells the radio/amp/audioPlayer a frequency, another integer for amplitude, etc...(over simplified because I don't know what other data is stored in an audio file).
2). If it is stored in an integer format, is there a way to read the integers and analyze it. If it is not stored in an integer format, how is it stored, and is there a way to convert it to an integer format?
3). In visual representations of an audio files like this one, it seems more clear what is what. It seems like the frequency is where on the circle the audio is represented, and the amplitude is how high it jumps. Is this right? Or does it just appear that way and I am understanding it incorrectly.
4). Is this task harder than I think it is? Considering I haven't found any good explanations or tutorials on how to do so, I am skeptical on how easy this would be.
(Sorry if this was poorly phrased, first question on stack and I am just illiterate :^)
I read a question about a similar topic on stackoverflow and I have part of the solution to my problem, let me explain what the problem is;
I need to know each and every block's position, and on the question that I read the questioner mentioned that the 3 vectors for "plane" are the determinants of the position, but I read the 1 answer that was there, and also checked the webpage the questioner provided and I couldn't understand it fully, could anyone please simplify it for me, this is holding me back from parsing VMF files.
I have a problem where a guy has to go through several pillars, where they are connected by bridges with holes. The guy must choose the best way trough the pillars. The best way is the way with less holes from the beginning pillar to the last one.
Here is an image provided with the problem.
The program will receive as input a description of the number off holes beetween every pillar and the number of pillars and bridges. The guy must go in only one direction towards the last pillar (no going back).
To me it looks like a tree search problem, but I was told i shouldnt use pointers in this problem cause there is a way to organize and solve it without using classic C tree definitions in assembly (where it d be much harder), only by using recursion.
How can i organize the "way tree" without using dinamic vectors/pointers?
You can make a 'nxn'-matrix (an array of length n^2), where matrix[i, j] is the quantity of holes between them.
If there's no path between the nodes i and j, the quantity of holes is infinity (2^31-1).
Then you can find the best path using recursion or just using the Dijkstra algorithm.
Now that Wolfram Alpha is released, I am interested in finding out if it can be used as a time-saver in daily programming.
What would you use Wolfram Alpha to do, that earlier took you more time to do manually?
I guess the "Web and Computer systems"-examples is a good start, but there must be more hidden gems that will be really practical for us programmers.
A short list of examples:
MD5-hashing / SHA-hashing
Quick lockup of unicode and HTML-codes for symbols
Color-codes
Please only include one search query per answer, then we can rate them to get the best ones to the top.
(I made this one a community-wiki, since we will be using the voting for ranking)
Note: If some of the links in the answers don't work (eg: wolfram doesn't find any results, then replace all + with spaces..
I might 'save time' by not playing around with it and doing real work instead. :)
Calculating lift coefficients of NACA profiles (example).
(I made a program for this, but it's nice to have the option to do it quick)
I probably won't use it for anything. I don't know about you, but I deal with enough black boxes on a daily basis, and I'd rather use the ones that have been tried and tested thoroughly.
This might come back to haunt me later, but it strikes me that although there might be a point to WA used in a mechanical manner, from my perspective I'm thinking it's not the hard calculable information questions which are the problem which needs to be solved, it's the soft human data which defies classification or rigid modelling. Google seem to understand this, not sure Stephen Wolfram does.
OTOH it could be that anyone can be Colin Laney now.
Someone double check me here:
The MD5 hash of "Wolfram Alpha" (no quotes) is:
882b 0be2 79eb 7e88 86cd 3dae 19c1 d267
And not:
a615 9984 9aee b7be 3091 68bc 0ab7 ?
EDIT: The hash changes every time given the same query...what kind of hash is this?
http://www14.wolframalpha.com/input/?i=MD5%22Wolfram+Alpha%22