histogram

问题 I am working grass weed detection. I have started to extract features from the HoG descriptor. As studied from the HoG literature that the HoG is not rotation invariant. I have total 18 images of each class of grass weed and there is two classes. In my training and testing database I have rotated each image [5 10 15 20 ... 355] degree. training and testing is done using LibSVM package. and I am getting accuracy of about 80%. My question is if the HoG is not rotation invariant then how can I

问题 I've done the nearest neighbour program in matlab for 547 points and I result with a cell array of size <547x1 cell> here are the data: Cell array = [1x4 double] [1x6 double] [1x6 double] [1x6 double] [1x6 double] [1x6 double] [1x6 double] [1x6 double] [1x6 double] [1x6 double] [1x6 double] [1x6 double] [1x5 double] [1x6 double] [1x7 double] [1x6 double] [1x6 double] [1x6 double] [1x6 double] [1x6 double] [1x6 double] [1x6 double] [1x6 double] [1x6 double] [1x6 double] [1x6 double] [1x3

问题 I have a vector that I want to print a histogram of of data for. This data ranges from -100 to +100. The amount of data around the outer edges is insignificant and therefore I don't want to see it. I am most interested in showing data from -20 to +20. 1.) How can I limit that window to print on my histogram? The amount of data I have at 0 outnumbers of the amount of data I have anywhere in the dataset by a minimum of 10:1. When I print the histogram, the layout of element frequency is lost

问题 The problem for me is how plot (using gnuplot) bars with different styles in a figure so that they can be print. Take data from http://www.ibm.com/developerworks/aix/library/au-gnuplot/ for example, the data is: #Disk.txt hdisk2 420 425 410 hdisk3 700 780 760 hdisk4 450 450 452 hdisk5 680 702 690 hdisk6 320 330 329 hdisk7 530 515 514 #Gnuplot set terminal png truecolor set output "diskimage.png" set style data histograms set style fill solid 1.00 border -1 plot "disk.txt" using 2:xtic(1)

问题 I'm trying to write a kernel to get the character frequencies of a string. First, here is the code I have for kernel right now: _kernel void readParallel(__global char * indata, __global int * outdata) { int startId = get_global_id(0) * 8; int maxId = startId + 7; for (int i = startId; i < maxId; i++) { ++outdata[indata[i]]; } } The variable inData holds the string in the global memory, and outdata is an array of 256 int values in the global memory. Every workitem reads 8 symbols from the

问题 Using python 2.6: I have a dictionary where each key contains a list of values. I want to look at all the values in the dictionary and tally how many times each appears across all keys. I have been looking at itervalues() or for value in dictionary.values(): for a start, and also the .count() function, but I need to return a histogram. for example: print dictionary would return {'test' : ['spam', 'eggs', 'cheese', 'spam'], 'test2' : ['spam', 'cheese', 'goats']} and I want something to tell me

问题 I need to make a histogram of events over a period of time. My dataset gives me the time of each event in the format ex. 2013-09-03 17:34:04, how do I convert this into something I'm able to plot in a histogram i Python? I know how to do it the other way around with the datetime and time commands. By the way my dataset contains above 1.500.000 datapoint, so please only solutions that can be automated by loops or something like that ;) 回答1: Use time.strptime() to convert the local time string

问题 Typically if I need to make a histogram with labels I will use hist(rnorm(100),labels=TRUE) . However if my data is factors then I need to use plot(as.factor(c("a","a","b"))) . The issue with this is that labels=TRUE will not work with plot ; how do I fix this ? I preferably want a solution without needing to load fancy packages. 回答1: You are actually creating a bar plot in the second example The following will work # your variable fact <- as.factor(c('a','a','b')) # b <- plot(fact) text(x=b

问题 I want to plot the distribution of the following dataset (column maxnet ). If I do the following in Python using Pandas DataFrame: df['maxnet'].hist(bins=10,range=(5,11), grid=False, alpha=0.3, histtype="stepfilled") I get the following figure: As you can see, I don't have the x-axis values centered under each bar. I want the x-values (6, 7, 8, 9, 10) to be centered under the bar. How can I do that? Also, if I want to change the x-axis label for (Dec6, Dec7, Dec8, Dec9, Dec10), still centered

问题 This question was migrated from Cross Validated because it can be answered on Stack Overflow. Migrated 6 years ago . I hope this question is beyond "read the manual". My task is simple, just to plot the following, but the plot in the middle should be a filled.contour plot: http://gallery.r-enthusiasts.com/graph/Scatterplot_with_marginal_histograms_78 Background: I prefer filled.contour rather than hist2d. Because, I could use kernel smooth, so the plot for discrete data won't be too ugly. I