First up, this is most certainly homework (so no full code samples please). That said...
I need to test an unsupervised algorithm next to a supervised algorithm, using the Neural... moreFirst up, this is most certainly homework (so no full code samples please). That said...
I need to test an unsupervised algorithm next to a supervised algorithm, using the Neural Network toolbox in Matlab. The data set is the UCI Artificial Characters Database. The problem is, I've had a good tutorial on supervised algorithms, and been left to sink on unsupervised.
So I know how to create a self organising map using selforgmap, and then I train it using train(net, trainingSet). I don't understand what to do next. I know that it's clustered the data I gave it into (hopefully) 10 clusters (one for each letter).
Two questions then:
How can I then label the clusters (given that I have a comparison pattern)?
Am I trying to turn this into a supervised learning problem when I do this?
How can I create a confusion matrix on (another) testing set to compare to the supervised algorithm?
I think I'm missing something conceptual or jargon-based here - all my searches come up with supervised learning... less
I'm trying to understand the backpropagation algorithm with an XOR neural network as an example. For this case there are 2 input neurons + 1 bias, 2 neurons in the hidden layer +... moreI'm trying to understand the backpropagation algorithm with an XOR neural network as an example. For this case there are 2 input neurons + 1 bias, 2 neurons in the hidden layer + 1 bias, and 1 output neuron.
A B A XOR B 1 1 -1 1 -1 1 -1 1 1 -1 -1 -1
(source: wikimedia.org)
I'm using stochastic backpropagation.
After reading a bit more I have found out that the error of the output unit is propagated to the hidden layers... initially this was confusing, because when you get to the input layer of the neural network, then each neuron gets an error adjustment from both of the neurons in the hidden layer. In particular, the way the error is distributed is difficult to grasp at first.
Step 1 calculate the output for each instance of input.Step 2 calculate the error between the output neuron(s) (in our case there is only one) and the target value(s):Step 3 we use the error from Step 2 to calculate the error for each hidden unit h:
The 'weight kh' is the weight between the hidden unit h and the output... less
From my understanding, Hbase is the Hadoop database and Hive is the data warehouse.
Hive allows to create tables and store data in it, you can also map your existing HBase tables to Hive and operate on them.
why we should use hbase if hive do all that? can we use hive by itself? I'm confused :(
I am trying to collect data from a .txt file and add it into a matrix in Matlab for plotting purposes, but there seems to be an error when collecting the data. It seems to be... moreI am trying to collect data from a .txt file and add it into a matrix in Matlab for plotting purposes, but there seems to be an error when collecting the data. It seems to be happening with the time record.
I am using the following code snippet.
Error using textscan
Unable to parse the format character vector at position 16 ==> %{HH:MM:SS}T %f %f %f %f %f %f %f %d %d %d %f %f %f %f %f %f %f %f %f %f
%f %f %f %f... less
is their any possible way to call all the R packages/libraries and functions (packages like raster, rgdal, maptools etc.) in .net framework so that i am able to access all the features of R and run R script using .Net frontend....
I'm working on machine learning problem and want to use linear regression as learning algorithm. I have implemented 2 different methods to find parameters theta of linear... moreI'm working on machine learning problem and want to use linear regression as learning algorithm. I have implemented 2 different methods to find parameters theta of linear regression model: Gradient (steepest) descent and Normal equation. On the same data they should both give approximately equal theta vector. However they do not.
Both theta vectors are very similar on all elements but the first one. That is the one used to multiply vector of all 1 added to the data.
Here is how the thetas look like (fist column is output of Gradient descent, second output of Normal equation):
Grad desc Norm eq -237.7752 -4.6736 -5.8471 -5.8467 9.9174 9.9178 2.1135 2.1134 -1.5001 -1.5003 -37.8558 -37.8505 -1.1024 -1.1116 -19.2969 -19.2956 66.6423 66.6447 297.3666 296.7604 -741.9281 -744.1541 296.4649 296.3494 146.0304 144.4158 -2.9978 -2.9976 -0.8190 -0.8189
What can cause the difference in theta(1, 1) returned by gradient descent compared to theta(1, 1) returned by normal equation? Do I have bug in my... less
This is kind of naive question but I am new to NoSQL paradigm and don't know much about it. So if somebody can help me clearly understand difference between the HBase and Hadoop... moreThis is kind of naive question but I am new to NoSQL paradigm and don't know much about it. So if somebody can help me clearly understand difference between the HBase and Hadoop or if give some pointers which might help me understand the difference.
Till now, I did some research and acc. to my understanding Hadoop provides framework to work with raw chunk of data(files) in HDFS and HBase is database engine above Hadoop, which basically works with structured data instead of raw data chunk. Hbase provides a logical layer over HDFS just as SQL does. Is it correct? less