frequency

Why do we use only the first buffer in aurioTouch project

安稳与你 提交于 2019-12-05 21:22:07
I'm investigating aurioTouch2 sample code. And I noticed, that when we analize audio data, we use only the first buffer of this data, and never other buffers. in void FFTBufferManager::GrabAudioData(AudioBufferList *inBL) function: UInt32 bytesToCopy = min(inBL->mBuffers[0].mDataByteSize, mAudioBufferSize - mAudioBufferCurrentIndex * sizeof(Float32)); memcpy(mAudioBuffer+mAudioBufferCurrentIndex, inBL->mBuffers[0].mData, bytesToCopy); in function static OSStatus PerformThru( void *inRefCon, AudioUnitRenderActionFlags *ioActionFlags, const AudioTimeStamp *inTimeStamp, UInt32 inBusNumber, UInt32

How can I resize the boxes in a boxplot created with R and ggplot2 to account for different frequencies amongst different boxplots? [duplicate]

回眸只為那壹抹淺笑 提交于 2019-12-05 14:07:43
This question already has answers here : Is there an equivalent in ggplot to the varwidth option in plot? (2 answers) Closed 5 years ago . I have a boxplot that I made in R with ggplot2 analagous to the sample boxplot below. The problem is, for the values on the y axis (in this sample, the number of cylinders in the car) I have very different frequencies -- I may have included 2 8 cylinder cars, but 200 4 cylinder cars. Because of this, I'd like to be able to resize the boxplots (in this case, change the height along the y axis) so that the 4 cylinder boxplot is a larger portion of the chart

Is there an library in Java for emitting a certain frequency constantly?

感情迁移 提交于 2019-12-05 10:58:48
Right, well. First time I'm actually using Java to fix a problem. I bought a new headphone set called Sennheiser 120 HD; but there's an issue. If there isn't a constant emission of audio then the base for the headphones will eventually time out and turn off. The headphones are spammed with static, which is horrible on the ears. The solution to this for me currently is playing music 24/7 to prevent the static of death. Maybe I'm weird, but I don't want to listen to music 24/7. I believe a workable solution for this would be to constantly emit a sound that the base can detect but I can't hear.

How to draw a frequency spectrum from a Fourier transform

此生再无相见时 提交于 2019-12-05 06:14:27
问题 I want to plot the frequency spectrum of a music file (like they do for example in Audacity). Hence I want the frequency in Hertz on the x-axis and the amplitude (or desibel) on the y-axis. I devide the song (about 20 million samples) into blocks of 4096 samples at a time. These blocks will result in 2049 (N/2 + 1) complex numbers (sine and cosine -> real and imaginary part). So now I have these thousands of individual 2049-arrays, how do I combine them? Lets say I do the FFT 5000 times

Find the N-th most frequent number in the array

China☆狼群 提交于 2019-12-05 05:30:34
Find the nth most frequent number in array. (There is no limit on the range of the numbers) I think we can (i) store the occurence of every element using maps in C++ (ii) build a Max-heap in linear time of the occurences(or frequence) of element and then extract upto the N-th element, Each extraction takes log(n) time to heapify. (iii) we will get the frequency of the N-th most frequent number (iv) then we can linear search through the hash to find the element having this frequency. Time - O(NlogN) Space - O(N) Is there any better method ? Your method is basically right. You would avoid final

Unable to get correct frequency value on iphone

∥☆過路亽.° 提交于 2019-12-04 21:22:33
I'm trying to analyze frequency detection algorithms on iOS platform. So I found several implementations using FFT and CoreAudio ( example 1 and example 2 ). But in both cases there is some imprecision in frequency exists: (1) For A4 (440Hz) shows 441.430664 Hz. (1) For C6 (1046.5 Hz) shows 1518.09082 Hz. (2) For A4 (440Hz) shows 440.72 Hz. (2) For C6 (1046.5 Hz) shows 1042.396606 Hz. Why this happens and how to avoid this problem and detect frequency in more accurate way? Resolution in the frequency domain is inversely related to number of FFT bins. You need to either: increase the size of

Converting word frequency to a graphical histogram in python

孤者浪人 提交于 2019-12-04 19:21:15
This is what I have right now, thanks to Pavel Anossov. I am trying to convert the word frequency that has been outputed into asterisks. import sys import operator from collections import Counter def candidateWord(): with open("sample.txt", 'r') as f: text = f.read() words = [w.strip('!,.?1234567890-=@#$%^&*()_+')for w in text.lower().split()] #word_count[words] = word_count.get(words,0) + 1 counter = Counter(words) print("\n".join("{} {}".format(*p) for p in counter.most_common())) candidateWord() This is what I have right now as an output. how 3 i 2 am 2 are 2 you 2 good 1 hbjkdfd 1 The

Grouping and Computing Frequency ,Pandas

岁酱吖の 提交于 2019-12-04 14:20:08
问题 I have a dataframe : df = pd.DataFrame({'Type' : ['Pokemon', 'Pokemon', 'Bird', 'Pokemon', 'Bird', 'Pokemon', 'Pokemon', 'Bird'],'Name' : ['Jerry', 'Jerry', 'Flappy Bird', 'Mudkip','Pigeon', 'Mudkip', 'Jerry', 'Pigeon']}) and i need to group the observations w.r.t their types i.e all pokemon types together with their respective names . And i need to add another column which has the frequency of occurrence of the names in the types. It should look like : Type Name Frequency Pokemon Jerry 3

Sorting entire csv by frequency of occurence in one column

一笑奈何 提交于 2019-12-04 12:04:27
I have a large csv file, which is a log of caller data. A short snippet of my file: CompanyName High Priority QualityIssue Customer1 Yes User Customer1 Yes User Customer2 No User Customer3 No Equipment Customer1 No Neither Customer3 No User Customer3 Yes User Customer3 Yes Equipment Customer4 No User I want to sort the entire list by the frequency of occurrence of customers so it will be like: CompanyName High Priority QualityIssue Customer3 No Equipment Customer3 No User Customer3 Yes User Customer3 Yes Equipment Customer1 Yes User Customer1 Yes User Customer1 No Neither Customer2 No User

Calculating Entropy

强颜欢笑 提交于 2019-12-04 08:27:54
问题 I've tried for several hours to calculate the Entropy and I know I'm missing something. Hopefully someone here can give me an idea! EDIT: I think my formula is wrong! CODE: info <- function(CLASS.FREQ){ freq.class <- CLASS.FREQ info <- 0 for(i in 1:length(freq.class)){ if(freq.class[[i]] != 0){ # zero check in class entropy <- -sum(freq.class[[i]] * log2(freq.class[[i]])) #I calculate the entropy for each class i here }else{ entropy <- 0 } info <- info + entropy # sum up entropy from all