frequency

问题 I've been looking over the Android Wifi direct APIs and I can't seem to find out if it is possible to change the frequency/channel Wifi direct uses to communicate? (channels 1, 6, or 11 for example) Does anybody know if this is possible with the developer API? If not, does anybody know if there is some third party library that could possibly require root access to accomplish this? Thanks in advance for any help you can provide. 回答1: In order to change the channel of the Wifi Direct of your

问题 I want to record sound (voice) using PortAudio (PyAudio) and output the corresponding sound wave on the screen. Hopeless as I am, I am unable to extract the frequency information from the audio stream so that I can draw it in Hz/time form. Here's an example code snippet that records and plays recorded audio for five seconds, in case it helps any: p = pyaudio.PyAudio() chunk = 1024 seconds = 5 stream = p.open(format=pyaudio.paInt16, channels=1, rate=44100, input=True, output=True) for i in

问题 I want to record sound (voice) using PortAudio (PyAudio) and output the corresponding sound wave on the screen. Hopeless as I am, I am unable to extract the frequency information from the audio stream so that I can draw it in Hz/time form. Here's an example code snippet that records and plays recorded audio for five seconds, in case it helps any: p = pyaudio.PyAudio() chunk = 1024 seconds = 5 stream = p.open(format=pyaudio.paInt16, channels=1, rate=44100, input=True, output=True) for i in

问题 I have a single series of values (i.e. one column of data), and I would like to create a plot with the range of data values on the x-axis and the frequency that each value appears in the data set on the y-axis. What I would like is very close to a Kernel Density Plot: # Kernel Density Plot d <- density(mtcars$mpg) # returns the density data plot(d) # plots the results and Frequency distribution in R on stackoverflow. However, I would like frequency (as opposed to density) on the y-axis.

问题 I am brand new to R. I need to plot a pie graph. Now I have tried my best but it's not generating a pie chart for me. Below is my code. socialIssue <- matrix(c(245,112,153,71,133,306),ncol=1,byrow=T) rownames(socialIssue) <- c("Housing","Transportation","Health Care","Education","Food","Other") colnames(socialIssue) <- c("Frequency") socialIssue <- as.table(socialIssue) socialIssue/sum(socialIssue) cols <- rainbow(nrow(socialIssue)) pie(socialIssue$Frequency, labels=paste0(round(socialIssue

问题 I've had a look at other similar questions already but haven't been able to apply the answers to my program. At the moment the frequencies are printed in ascending order, what do I change to make it print it in descending order? from sys import argv frequencies = {} for ch in 'ABCDEFGHIJKLMNOPQRSTUVWXYZ': frequencies[ch] = 0 for filename in argv[1:]: try: f = open(filename) except IOError: print 'skipping unopenable', filename continue text = f.read() f.close() for ch in text: if ch.isalpha()

问题 I am trying to find a way to get the values of max/min freq of characters in a string E.g. helpme would have max freq = 2 and min freq = 1 (there are 2 e's and there are other letters that occurs once) another E.g. aaaa would have max freq = 4 and min freq = 4 I am trying to program this, but I don't know what to do after I receive the string by using scanf. Assume that there are only lowercase and there are no space between words. Additionally, I prefer more of a brute force search over an

问题 This seems to be basic, but I wont get it. I am trying to compute the frequency table in R for the data as below 1 2 2 1 3 1 I want to transport the the two way frequencies in csv output, whose rows will be all the unique entries in column A of the data and whose columns will be all the unique entries in column B of the data, and the cell values will be the number of times the values have occurred. I have explored some constructs like table but I am not able to output the values correctly in

问题 I've a dataset that denotes the list of authors of many technical reports. Each report can be authored by one or multiple people: a = [ ['John', 'Mark', 'Jennifer'], ['John'], ['Joe', 'Mark'], ['John', 'Anna', 'Jennifer'], ['Jennifer', 'John', 'Mark'] ] I've to find the most frequent pairs, that is, people that had most collaborations in the past: ['John', 'Jennifer'] - 3 times ['John', 'Mark'] - 2 times ['Mark', 'Jennifer'] - 2 times etc... How to do this in Python? 回答1: Use a collections

问题 I've a dataset that denotes the list of authors of many technical reports. Each report can be authored by one or multiple people: a = [ ['John', 'Mark', 'Jennifer'], ['John'], ['Joe', 'Mark'], ['John', 'Anna', 'Jennifer'], ['Jennifer', 'John', 'Mark'] ] I've to find the most frequent pairs, that is, people that had most collaborations in the past: ['John', 'Jennifer'] - 3 times ['John', 'Mark'] - 2 times ['Mark', 'Jennifer'] - 2 times etc... How to do this in Python? 回答1: Use a collections