frequency

There's this tech-festival in IIT-Bombay, India, where they're having an event called "Artbots" where we're supposed to design artbots with artistic abilities. I had an idea about a musical robot which takes a song as input, detects the notes in the song and plays it back on a piano. I need some method which will help me compute the pitches of the notes of the song. Any idea/suggestion on how to go about it? This is exactly what I'm doing here as my last year project :) except one thing that my project is about tracking the pitch of human singing voice (and I don't have the robot to play the

How do I get the most frequently occurring category for each tag in MySQL? Ideally, I would want to simulate an aggregate function that would calculate the mode of a column. SELECT t.tag , s.category FROM tags t LEFT JOIN stuff s USING (id) ORDER BY tag; +------------------+----------+ | tag | category | +------------------+----------+ | automotive | 8 | | ba | 8 | | bamboo | 8 | | bamboo | 8 | | bamboo | 8 | | bamboo | 8 | | bamboo | 8 | | bamboo | 10 | | bamboo | 8 | | bamboo | 9 | | bamboo | 8 | | bamboo | 10 | | bamboo | 8 | | bamboo | 9 | | bamboo | 8 | | banana tree | 8 | | banana tree |

It's been asked a lot, but I still stuck about implement FFT class on Android I need to process my audio data using FFT... I already read the almost same question here How can I get frequency data from PCM using FFT and here How to get frequency from fft result? and more questions but still find no answer even after I tried the answers given... FFT Class I'm using: http://www.cs.princeton.edu/introcs/97data/FFT.java The complex class to go with it: http://introcs.cs.princeton.edu/java/97data/Complex.java.html Here's my code import java.io.File; import java.io.FileInputStream; import java.io

I have a .txt file that looks something like this: rs1 NC AB NC rs2 AB NC AA rs3 NC NC NC ... For each row, I would like to count the frequencies of "NC", so that my output will be something like below: rs1 2 rs2 1 rs3 3 ... Can someone tell me how to do this in R or in Linux? Many thanks! df$count <- rowSums(df[-1] == "NC") # V1 V2 V3 V4 count # 1 rs1 NC AB NC 2 # 2 rs2 AB NC AA 1 # 3 rs3 NC NC NC 3 We can use rowSums on the matrix that is created from this expression df[-1] == "NC" . dat <- read.table(text="rs1 NC AB NC rs2 AB NC AA rs3 NC NC NC") dat <- rbind(dat, dat, dat, dat) You can use