histogram

问题 An array of frequency is created. int arr[10]; arr[0] = 24; arr[1] = 28; arr[2] = 23; arr[3] = 29; //and so on How do i draw a histogram using OpenCV in C++ based on the array? 回答1: OpenCV is not really suited for plotting. However, for simple histograms, you can draw a rectangle for each column (eventually with alternating colors) This is the code: #include <opencv2\opencv.hpp> #include <algorithm> using namespace std; using namespace cv; void drawHist(const vector<int>& data, Mat3b& dst,

问题 I am working on a project and I would like to display a single line histogram that looks like a bar graph except each line in the bar graph represents a pixel and its greyscale value. I have a array full of greyscale values, I just need to put them into this histogram and have it display the lines which will represent the values.. sort of like this IMAGE [minimize][maximize][close] picture histogram I (Loaded Picture) I I I I I I I I I [open][save] And below is the code loading the array... I

问题 Here is a question for R-users. I am interested in drawing a histogram with points stacked up, instead of a bar. For example if the data is (1,1,2,1,2,3,3,3,4,4), then I would like to see three points stacked up at 1, 2 points stacked up at 2 and so on. What is the best way to do this in R? 回答1: Greg Snow's TeachingDemos package contains a dots(x, ...) function which seems to fit your need: dots( round( rnorm(50, 10,3) ) ) 回答2: You can do this yourself pretty quickly: x <- c(1,1,2,1,2,3,3,3,4

问题 I am writing a R code that allows users to select columns from a data and plots histograms for each of them. Hence, I am using a 'for' loop to generate the required number of plots using the ggplot2 library and save them in a single list. But the problem I am facing is that, at every iteration of the 'for' loop, all objects in the list are storing the same plot. Thus, the final output consists of a grid of histograms, labeled differently but depicting the same(last) column. I understand that

问题 geom_bar seems to work best when it has fixed width bars - even the spaces between bars seem to be determined by width, according to the documentation. When you have variable widths, however, it does not respond as I would expect, leading to overlaps or gaps between the different bars (as shown here). To see what I mean, please try this very simple reproducible example: x <- c("a","b","c") w <- c(1.2, 1.3, 4) # variable widths y <- c(9, 10, 6) # variable heights ggplot() + geom_bar(aes(x = x,

问题 I am working on a simulation system. I will soon have experimental data (histograms) for the real-world distribution of values for several simulation inputs. When the simulation runs, I would like to be able to produce random values that match the measured distribution. I'd prefer to do this without storing the original histograms. What are some good ways of Mapping a histogram to a set of parameters representing the distribution? Generating values that based on those parameters at runtime?

问题 I'm new with R. I need to generate a simple Frequency Table (as in books) with cumulative frequency and relative frequency. So I want to generate from some simple data like > x [1] 17 17 17 17 17 17 17 17 16 16 16 16 16 18 18 18 10 12 17 17 17 17 17 17 17 17 16 16 16 16 16 18 18 18 10 [36] 12 15 19 20 22 20 19 19 19 a table like: frequency cumulative relative (9.99,11.7] 2 2 0.04545455 (11.7,13.4] 2 4 0.04545455 (13.4,15.1] 1 5 0.02272727 (15.1,16.9] 10 15 0.22727273 (16.9,18.6] 22 37 0

问题 this forum already helped me a lot for producing the code, which I expected to return a histogram of a specific variable overlayed with its empirical normal curve. I used ggplot2 and stat_function to write the code. Unfortunately, the code produced a plot with the correct histogram but the normal curve is a straight line at zero (red line in plot produced by the following code). For this minimal example I used the mtcars dataset - the same behavior of ggplot and stat_function is observed with

问题 I have a histogram with some small values and some very big values. How can I break the y-axis in two parts? EDIT: gnuplot sample: set style histogram columnstacked set style data histograms set key autotitle columnheader plot for [i=2:6] 'test.dat' using i test.dat: action device1 device2 device3 load 200 203 190 2 4 process 3 9 6 7 3 save 4 2 7 4 3 回答1: My answer is based on the example and comment on this website. In essence, you are looking for a broken y-axis , which can be achieved

问题 I am new to matplotlib (1.3.1-2) and I cannot find a decent place to start. I want to plot the distribution of points over time in a histogram with matplotlib. Basically I want to plot the cumulative sum of the occurrence of a date. date 2011-12-13 2011-12-13 2013-11-01 2013-11-01 2013-06-04 2013-06-04 2014-01-01 ... That would make 2011-12-13 -> 2 times 2013-11-01 -> 3 times 2013-06-04 -> 2 times 2014-01-01 -> once Since there will be many points over many years, I want to set the start date