histogram

问题 I am trying to calculate Histogram of all columns from a CSV file using Spark Scala. I found that DoubleRDDFunctions supporting Histogram. So I coded like following for getting histogram of all columns. Get column count Create RDD[double] of each column and calculate Histogram of each RDD using DoubleRDDFunctions var columnIndexArray = Array.tabulate(rdd.first().length) (_ * 1) val histogramData = columnIndexArray.map(columns => { rdd.map(lines => lines(columns)).histogram(6) }) Is it a good

问题 In ipython Notebook, first create a pandas Series object, then by calling the instance method .hist(), the browser displays the figure. I am wondering how to save this figure to a file (I mean not by right click and save as, but the commands needed in the script). 回答1: Use the Figure.savefig() method, like so: ax = s.hist() # s is an instance of Series fig = ax.get_figure() fig.savefig('/path/to/figure.pdf') It doesn't have to end in pdf , there are many options. Check out the documentation.

问题 This is my goal: Plot the frequency of y according to x in the z axis. These are my problems: I have a two columns array ( x and y ) and need to divide x into classes (p.ex. 0.2 ou 0.5) and calculate the frequency of y for each class of x . The plot should appear like a x-y plot in the "ground" plan and the frequency in the z axis. It could be like a surface or a 3D histogram. I tried to make it using the hist3D function of plot3D package but I don't know what I am doing wrong. This is an

问题 I plot a vector distribution with qplot that I don't know its distribution in advance, it's calculated in a function. I just know that the x values are between 0 and 1. I use the below command line and get the attached histogram. As the distribution is jammed, how can I make it more spread so that the distribution becomes clear? which parameters to use or other functions that produce histogram? Moreover how to color so that the bins becomes more distiguishable? keeping the color legend may or

问题 Folks, I am plotting histograms using geom_histogram and I would like to label each histogram with the mean value (I am using mean for the sake of this example). The issue is that I am drawing multiple histograms in one facet and I get labels overlapping. This is an example: library(ggplot2) df <- data.frame (type=rep(1:2, each=1000), subtype=rep(c("a","b"), each=500), value=rnorm(4000, 0,1)) plt <- ggplot(df, aes(x=value, fill=subtype)) + geom_histogram(position="identity", alpha=0.4) plt <-

问题 I want to dynamically update two separate series in a jfree chart histogram. When i look at HistogramDataset it doesn't seem like there is a method for that. Is this possible? I know it can be done in SimpleHistogramDataset but I need to have two series on this chart. 回答1: Some alternatives: Replace the HistogramDataset with each update: chart.getXYPlot().setDataset(newDataset); Add a second SimpleHistogramDataset and XYItemRenderer to the plot: SimpleHistogramDataset newDataset =

问题 I'm using HOG in order to extract a set of features trough an Image A. the HOG returns a features' vector of 1xN elements. However the linear SVM accept only 2 features for each sample i.e the training data matrix's size is Mx2. so how i can adapt the HOG vector to be trained on linear SVM. Please help me. Thanks 回答1: What do you mean by "the linear SVM accept only 2 features for each sample"? You may be confused on how the SVM function accepts its training data. Here's a quick example of how

问题 First off, I've already read the following thread: ggplot2 - Multi-group histogram with in-group proportions rather than frequency I followed the ddply suggestion and it didn't seem to work for my data. Logically the code should work perfectly on my dataset and I have no idea what I'm doing wrong. Overall: I'd like to make a histogram (I'm learning ggplot) that displays the genotype frequency in each of my study groups. Something like this: Here's a mock data set that mirrors my own: df<-data

问题 I am dealing with a set of time series data. And I have separated this set into 108 windows by time(a single time window is 1-month long). And then I plot a histogram for each window. So I have 108 histograms, from time window1 to window108 they are in chronological order(from November 2006 to October 2015, 108 time windows). What I want to do: is to plot all these 108 histograms as a one horizontally long histogram. So it is like to add them altogether. For example, plot histogram for

问题 figure; histogram = hist(np,180); name=['histogram-' int2str(k) '.png']; %% k is the iterator so basically I want to save all the images using a loop. imwrite(out,name); The image I got is only a horizontal line. Does someone know how to fix this? 回答1: you can use savefig instead of imwrite here is the doc http://www.mathworks.ch/ch/help/matlab/ref/savefig.html savefig(h,filename) h is the handle of figure. you could skip h to save the current figure. (edit) savefig may not be there depending