histogram

问题 I'm wondering how to plot a 2d histogram of an HSV Mat in opencv c++. My current code attempting to display it fails miserably. I've looked around on how to plot histograms and all the ones I've found were those plotting them as independent 1d histograms. Here's my current output with the number of hue bins being 30 and saturation bins being 32: Here's another output with the number of hue bins being 7 and saturaation bins being 5: I would like it to look more like the result here http://docs

问题 I'm wondering how to plot a 2d histogram of an HSV Mat in opencv c++. My current code attempting to display it fails miserably. I've looked around on how to plot histograms and all the ones I've found were those plotting them as independent 1d histograms. Here's my current output with the number of hue bins being 30 and saturation bins being 32: Here's another output with the number of hue bins being 7 and saturaation bins being 5: I would like it to look more like the result here http://docs

问题 I want to make a simple histogram which involves two vectors , values <- c(1,2,3,4,5,6,7,8) freq <- c(4,6,4,4,3,2,1,1) df <- data.frame(values,freq) Now the data.farame df consists the following values : values freq 1 4 2 6 3 4 4 4 5 3 6 2 7 1 8 1 Now I want to draw a simple histogram, in which value s are on the x axis and freq is on y axis. I am trying to use the hist function, but I am not able to give two variables. How can I make a simple histogram from this data? 回答1: using ggplot2:

问题 This question already has answers here : Closed 7 years ago . Possible Duplicate: How to plot two histograms together in R? I want to plot two histograms together, both of them having same x axis units and y axis units. Two histograms are taken from two files, inp1 and inp2. I have tried the following code but it is not working: x1<-hist(inp1, 120, plot = 0) x2<-hist(inp2, 120, plot = 0) hist(x1, x2, 240, plot = 1) 回答1: The kind of plot you want is not strictly speaking a histogram. You can

问题 This question already has answers here : Closed 7 years ago . Possible Duplicate: How to plot two histograms together in R? I want to plot two histograms together, both of them having same x axis units and y axis units. Two histograms are taken from two files, inp1 and inp2. I have tried the following code but it is not working: x1<-hist(inp1, 120, plot = 0) x2<-hist(inp2, 120, plot = 0) hist(x1, x2, 240, plot = 1) 回答1: The kind of plot you want is not strictly speaking a histogram. You can

问题 How can I make a histogram so that each row below is represented by a bar? Eg, x axis "2012-10-02" and y axis "126", "2012-10-03" and y axis "11352"... and so on. The 'date' variable is a Date vector. date steps 1 2012-10-02 126 2 2012-10-03 11352 3 2012-10-04 12116 4 2012-10-05 13294 5 2012-10-06 15420 6 2012-10-07 11015 7 2012-10-09 12811 8 2012-10-10 9900 9 2012-10-11 10304 10 2012-10-12 17382 Thank you 回答1: This is not a histogram. You've already aggregated the counts by date. barplot(df

问题 How can I make a histogram so that each row below is represented by a bar? Eg, x axis "2012-10-02" and y axis "126", "2012-10-03" and y axis "11352"... and so on. The 'date' variable is a Date vector. date steps 1 2012-10-02 126 2 2012-10-03 11352 3 2012-10-04 12116 4 2012-10-05 13294 5 2012-10-06 15420 6 2012-10-07 11015 7 2012-10-09 12811 8 2012-10-10 9900 9 2012-10-11 10304 10 2012-10-12 17382 Thank you 回答1: This is not a histogram. You've already aggregated the counts by date. barplot(df

问题 The following code read each row from a numpy ndarray and create multiple histograms on the same figure: fig, ax = plt.subplots(figsize=(10, 8)) fontP = FontProperties() fontP.set_size('small') for f in eval_list: local_id = getIndexByIdentifier(f) temp_sim = total_sim[local_id,:] c=np.random.rand(3,1) ax.hist(temp_sim, 10, ec=c, fc='none', lw=1.5, histtype='step', label=f) ax.legend(loc="upper left", bbox_to_anchor=(1.1,1.1),prop = fontP) Instead of including all histograms in one plot, how

问题 I faced an error when I tried to plot histogram in python. Could you please help me to solve this error? I think it is not a big issue, but I can find the solution yet. :( Code import matplotlib.pyplot as plt import csv import sys def analyze(): # datafile = 'test.csv' datafile = sys.argv[1] pieces = [] with open(datafile, 'rt') as f: data = csv.reader(f,delimiter = '\t') for d in data: pieces.append(d) x = [op for op, response, interval in pieces] y1 = [interval for op, response, interval in

问题 I recorded a sequence of depth images using Kinect v2. But the background brightness is not constant. But It keeps changing from dark to light and light to dark (i.e) . So I was thinking to use Histogram normalization of each image in a sequence to normalise the background to the same level. Can anyone please tell me how I can do this? 回答1: Matlab has a function for histogram matching and their site has some great examples too Just use any frame as the reference (I suggest using the first one