A friend and I are about to embark on creating a machine that performs some image comparison for sorting. I know about histogram comparison and am generally confident that a small grid of histograms per image precalculated and stored in columns in a database table will generally give us pretty good matches on the first pass because we a...
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...
How do you write the kind of histogram UI like the one in Task Manager in Windows? The best I could find is this one below http://www.codeproject.com/KB/custom-controls/performancecountercontrol.aspx But it is ASP.net web ui, which is not usable in my standalone executable project. I'm trying to write a performance history meter appl...
Let's say I have a database column 'grade' like this: |grade| | 1| | 2| | 1| | 3| | 4| | 5| Is there a non-trivial way in SQL to generate a histogram like this? |2,1,1,1,1,0| where 2 means the grade 1 occurs twice, the 1s mean grades {2..5} occur once and 0 means grade 6 does not occur at all. I don't mind if the...
I have a bunch of numbers I want to use to generate a histogram for a standard score. Therefore I compute the mean and the standard deviation of the numbers and normalize each x with this formula x' = (x-mean)/std_dev The result is a number between -4 and 4. I want to chart that result. I am looking for a way to group the numbers in o...
As part of a test bench I'm building, I'm looking for a simple class to calculate a histogram of integer values (number of iterations taken for an algorithm to solve a problem). The answer should be called something like this: Histogram my_hist = new Histogram(); for( uint i = 0; i < NUMBER_OF_RESULTS; i++ ) { myHist.AddValue( som...
Ok, here's some code in MATLAB: data = [1 1.5 2 3 4 4.5 5 6 7 7 7 0 0 0]; histc(data, [1:1:5]) histc(data, [1:1:5, inf]) histc(data, [-inf, 1:1:5]) which outputs the following: ans = 2 1 1 2 1 ans = 2 1 1 2 5 0 ans = 3 2 1 1 2 1 My question is, why does MATLAB return a useles...
Instead of implementing my own I was wondering if anyone knows of a histogram or bag datastructure implementation in Objective-C that I can use. Essentially a histogram is a hashmap of lists where the lists contain values that relate to their hash entry. A good example is a histogram of supermarket items where you place each group of it...
This is supposed to calculate the histogram of an 8-bit grayscale image. With a 1024x770 test bitmap, CreateTime ends up at around 890ms. How can I make this go (way, way) faster? EDIT: I should mention that this doesn't actually compute the histogram yet, it only gets the values out of the bitmap. So I really should have asked, what...
I'd like to represent on a distribution the plot that fit to it. I can't find how to do it (I'm a MATLAB beginner). Thanks for any help! ...
I'm taking a beginner Java class, with the assignment to create a histogram program with the following output: (100 and 10 are user inputs). How many numbers? 100 How many intervals? 10 Histogram -------------------------------------------------------- 1 ****(4) 2 ******(6) 3 ***********(11) 4 *****************(17) 5 *****...
I have an array of BitmapFrames and need to do a histogram stretch. I know this is different from a histogram equalization, and what the final outcome is... sorta. the problem is I have absolutely no idea what to do after I get the histogram. So far my code creates an array for the histogram so I know how many pixels of each value i hav...
There is a nice function that draws back to back histograms in Matlab. I need to create a similar graph in matplotlib. Can anyone show a working code example? ...
I searched around for ways to make rose diagrams (circular histograms) in Google Chart. The API has only radar diagrams, so it seems not technically possible (am I correct?). This wind rose example was the closest I came to a solution. Because I needed them, I figured out a way to fake them quickly using the Radar plots, Python and the ...
I have a very long list in a numpy.array. I want to generate a histogram for it. However, Numpy's built in histogram requires a pre-defined number of bins. What's the best way to generate a full histogram with one bin for each value? ...
I have to create a histogram/dictionary of all words found in parsing an html file. This includes a dictionary of all words found, and a histogram of their frequency. I cant think of how to do this with PHP/MySQL because there could be potentially 2000 words that would have to be INSERTED at once =/ Any ideas? ...
Is there a function in R that fits a curve to a histogram? Let's say you had the following histogram hist(c(rep(65, times=5), rep(25, times=5), rep(35, times=10), rep(45, times=4))) It looks normal, but it's skewed. I want to fit a normal curve that is skewed to wrap around this histogram. This question is rather basic, but I can't ...
Does anyone have sample wxWidgets code to display a histogram? wxMathPlot seems to be working great for my other plotting needs, but now I have a requirement for a histogram. Not being a UI developer I am a little bit like a fish out of water. Any suggestions or references are greatly appreciated. (I'd like it to be a dynamic histog...
I'm using ggplot2 to create panels of histograms, and I'd like to be able to add a vertical line at the mean of each group. But geom_vline() uses the same intercept for each panel (i.e. the global mean): require("ggplot2") # setup some sample data N <- 1000 cat1 <- sample(c("a","b","c"), N, replace=T) cat2 <- sample(c("x","y","z"), N, ...
I am having a hard time finding a library that will preform Histogram equalization of an Image. ...