frequency

问题 This question already has answers here : Counting the occurrences / frequency of array elements (36 answers) Closed 3 years ago . So i have this code Array.prototype.byCount= function(){ var itm, a= [], L= this.length, o= {}; for(var i= 0; i<L; i++){ itm= this[i]; if(!itm) continue; if(o[itm]== undefined) o[itm]= 1; else ++o[itm]; } for(var p in o) a[a.length]= p; return a.sort(function(a, b){ return o[b]-o[a]; }); } source This is almost what i need except that it does not return the number

问题 I just made an algorithm that counts the frequency of chars in a String. What I am confused about is how to sort the frequency so the character with the greatest number of occurences is listed at the top, and the least at the bottom. At first I tried having another variable 'fc' (for frequency counter) to coincide with my original counter variable 'k'. However I am stuck in the thought process of how to go about sorting this frequency, the fc var I made is just useless. Thanks for any help

问题 I am producing some demographic tables, to include race, sex, and ethnicity. One of the tables is a crosstab of sex and race by ethnicity (Hispanic / not Hispanic). So far, there are no Hispanic participants in the study, but the table needs to be produced and sent to interested parties (i.e., regulatory agencies). However, I have not been able to produce a table for the report. Obviously, the table would be all zeroes, but it is not being produced at all. It seems that this is a limitation

问题 This question already has answers here : Create columns from factors and count [duplicate] (2 answers) Closed 3 years ago . To get the question clear, let me start with one baby example of my data frame. ID <- c(rep("first", 2), rep("second", 4), rep("third",1), rep("fourth", 3)) Var_1 <- c(rep("A",2), rep("B", 2), rep("A",3), rep("B", 2), "A") Var_2 <- c(rep("C",2), rep("D",3) , rep("C",2), rep("E",2), "D") DF <- data.frame(ID, Var_1, Var_2) > DF ID Var_1 Var_2 1 first A C 2 first A C 3

问题 I am creating a tuner for Android (similar to a guitar tuner) and I am wondering how to allow the tuner to run continuously (for a couple minutes or so). I don't want it to be a service that runs in the background, just while the user is in my app. I have successfully used the AudioRecord class and am obtaining data that seems correct. I am in the process of filtering this data and finding the fundamental frequency of the input signal, but need help figuring out how to allow my tuner to run

问题 Below, I first find if variables X and Y have a value that is repeated less than 4 times. I find and list these values in low . I wonder, using BASE R, how can I transform low which is a list of table s to my desired output shown below? Note: The data below is toy, a functional answer is appreciated. data <- data.frame(id = c(rep("AA",4), rep("BB",2), rep("CC",2)), X = c(1,1,1,1,1,1,3,3), Y = c(9,9,9,7,6,6,6,6), Z = 1:8) mods <- c("X","Y") A <- setNames(lapply(seq_along(mods), function(i)

问题 Here is the code I used in R (using RGui 64-bit, R ver. 3.3.1) to plot a histogram of data along with a frequency polygon. I am not using ggplot2. How can I superimpose the frequency polygon on top of the histogram so that I don't have to do two separate graphs? That is, I want the histogram plotted, with the frequency polygon overlaid on top of it. # declare your variables data <- c(10, 7, 8, 4, 5, 6, 6, 9, 5, 6, 3, 8, + 4, 6, 10, 5, 9, 7, 6, 2, 6, 5, 4, 8, 7, 5, 6) # find the range range

问题 Say I have 5 items A, B, C, D, E in a questionnaire and got respondents to rank them. The data looks like this, > df rank1 rank2 rank3 rank4 rank5 1 A B C D E 2 A C B D E 3 C A B E D 4 B A C D E 5 A B D C E How do I count the frequency of each rank by item so the output looks like this, item rank1 rank2 rank3 rank4 rank5 1 A 3 2 0 0 0 2 B 1 2 2 0 0 3 C 1 1 2 1 0 4 D 0 0 1 3 1 5 E 0 0 0 1 4 回答1: We can use table after converting to factor using base R lvls <- sort(unique(unlist(df))) sapply(df

问题 I just finished writing an algorithm that finds values in an input integer array with max/min occurrences. My idea is to sort the array (all the occurrences are now in sequence) and use a <value:occurrences> pair to store for every value the number of occurrences correspondent. It should be O(nlogn) complexity but I think that there are some constant multipliers. What can I do to improve performance? #include <stdio.h> #include <stdlib.h> #include "e7_8.h" #define N 20 /*Structure for <value,

问题 I have an array that I want to get the most occurring elements, First scenario let arr1 = ['foo', 'foo', 'foo', 'bar', 'bar', 'bar', 'baz', 'baz'] let newArr = someFunc(arr1) so in this case I want the new array to have the value console.log(newArr) // ['foo', 'bar'] Because the value 'foo' and 'bar' was the most occurring element of the array Second scenario let arr2 = ['foo', 'foo', 'foo', 'bar', 'baz'] let newArr = someFunc(arr2) so in this case I want the new array to have the value