Sunday, August 29, 2010
Friday, August 27, 2010
matplotlib is a python 2D plotting library which produces publication quality figures in a variety of hardcopy formats and interactive environments across platforms. matplotlib can be used in python scripts, the python and ipython shell (ala MATLAB®* or Mathematica®†), web application servers, and six graphical user interface toolkits.
Monday, August 16, 2010
Wednesday, August 11, 2010
In statistics, point estimation involves the use of sample data to calculate a single value (known as a statistic) which is to serve as a "best guess" for an unknown (fixed or random) population parameter.
More formally, it is the application of a point estimator to the data.
In general, point estimation should be contrasted with interval estimation.
Point estimation should be contrasted with general Bayesian methods of estimation, where the goal is usually to compute (perhaps to an approximation) the posterior distributions of parameters and other quantities of interest. The contrast here is between estimating a single point (point estimation), versus estimating a weighted set of points (a probability density function). However, where appropriate, Bayesian methodology can include the calculation of point estimates, either as the expectation or median of the posterior distribution or as the mode of this distribution.
In a purely frequentist context (as opposed to Bayesian), point estimation should be contrasted with the specific interval estimation calculation of confidence intervals.
Friday, August 6, 2010
Thursday, August 5, 2010
15 HMM based articulatory detectors are adopted to generate log-likelihood rate features for a later stage NN to predict phone posteriors.
[NN/HMM] Introducing Phonetically Motivated, Heterogeneous Information into Automatic Speech Recognition
Tuesday, August 3, 2010
The scientists focused on the long-distance network of 383 brain regions and 6,602 long-distance brain connections that travel through the brain’s white matter, which are like the “interstate highways” between far-flung brain regions, he explained, while short-distance gray matter connections (based on neurons) constitute “local roads” within a brain region and its sub-structures.
Monday, August 2, 2010
Lossless audio files can be split by cue file using “shnsplit” (part of the “shntool” package). You will also need the “cuebreakpoints” tool (part of the “cuetools” package). To install cuetools and shntool in Ubuntu/ Kubuntu, open a terminal window and enter the following:
sudo apt-get install cuetools shntool
You will also need software for your prefered lossless audio format. For Monkey’s Audio you need to install “mac” – see here for details. For FLAC and WavPack formats you need to install “flac” and “wavpack” respectively:
sudo apt-get install flac wavpack
Shnsplit requires a list of break-points with which to split an audio file. Conveniently, cuebreakpoints prints the break-points from a cue or toc file in a format that can be used by shnsplit. You can pipe the output of cuebreakpoints to shnsplit as follows:
cuebreakpoints sample.cue | shnsplit -o flac sample.flac
In this example, a flac file called “sample.flac” is split according to the break-points contained in “sample.cue” and the results are output in the flac format.
The output file format is specified via the “-o” option. If you don’t specify an output format your split files will be in shntool’s default format (i.e., wave files, “wav”).
To split a monkey’s audio file by cue file and output the results in the flac format:
cuebreakpoints sample.cue | shnsplit -o flac sample.ape
Note that a default prefix “split-track” is used to name the output files. (The default output format is split-track01, split-track02, split-track03, …). You can specify your own prefix via the “-a” option.
To see all the options for shntool split type “shntool split -h” or “shnsplit -h”.
The audio files output by shnsplit do not contain tag data. However you can use the “cuetag” script (installed as part of the cuetools package) to transfer tag data directly from a cue file to your split audio files. You specify the individual audio files corresponding to the tracks contained in your cue file as follows:
cuetag sample.cue split-track01.flac split-track02.flac split-track03.flac split-track04.flac
This will transfer the tag data contained in “sample.cue” to the flac audio tracks “split-track01.flac” “split-track02.flac” “split-track03.flac” and “split-track04.flac”.
The above command could be streamlined as:
cuetag sample.cue split-track*.flac
Cuetag works with flac, ogg and mp3 files. The cuetag script is not currently able to handle file names containing spaces.
Note: If you are running flac version 1.1.4 or higher then you may need to make some small changes to the cuetag script before it will work correctly with flac files. Open the cuetag script (for Ubuntu installations it will be located at /usr/bin/cuetag) in a text editor and make these two changes: 1) search for the text “remove-vc-all” and replace it with “remove-all-tags”. 2) search for the “import-vc-from” and replace with “import-tags-from”.