See density and weights for a description of the possible semantics. We can use the following formula to find the best estimate of the median of any histogram: Best Estimate of Median: L + ( (n/2 – F) / f ) * w. 023 or 2. I have tried the following: intersect_pct <- st_intersection(nc, tr_buff) But this just gives me the intersection areas. Jul 10, 2022 · How can I calculate the area of intersecting region? I tried to find similar bins centers (to find zero-crossing), but I wasn't succeeded, I also tried to find the minimum between two bins with the same index, but it doesn't work for negative data. Apr 22, 2021 · I want to learn to manage histograms. The content of the page looks as follows: 1) Creation of Exemplifying Data. calcHist. Jul 2, 2015 · The code below plots of the sampling distribution of the mean and calculate 20 lots of 95% confidence intervals. Jan 8, 2011 · Calculate the H-S histogram for all the images and normalize them in order to compare them. Jan 18, 2023 · The function histogram_intersection() takes in two histograms as input, represented as numpy arrays, and calculates the histogram intersection by summing the minimum values of each bin between the two histograms. Applying a grid on the plot is not really an option because this plot will be a part of a multi-panel plot. image = cv2. seed(2) x1 <- sample(1:10, 100, replace = TRUE) x2 <- sample(1:10, 100, replace = TRUE) # Find points where x1 is above x2. 0227 So the proportion is 0. bin_edges array of Aug 6, 2017 · The histograms were generated from two different images. 2) Example 1: Modify Bins of Base R Histogram. (This is not easy to do in R, so use another technology to graph a relative frequency histogram. Jun 7, 2023 · Some of the code will be similar to How to plot the difference between two histograms, except density will be used in np. Nov 12, 2016 · In OpenCV two histograms can be compared using the function cv2. Sep 15, 2011 · @Huck Smith err then that is not a histogram. . the point of intersection (I need the x-value) of 2 or more normal distributions (fitted on a histogram) which have for example the following parameters: d=data. To normalize an array by using the function cv::normalize. In this tutorial, I will explain what histograms are and what you can do with them along with some basic methods for plotting histograms in R. Part of R Language Collective. This can be particularly useful when dealing with texture analysis and classification. You possibly want to read plot. Pass suitable histogram comparison method as parameter to this method. ), position="identity") +. For a grayscale image, its value is [0] and for a color image, you can pass [0], [1], or [2] to calculate a histogram of blue, green, or red channel respectively. Note that the sum of the histogram values will not be equal to 1 unless bins of unity width are chosen; it is not a probability mass function. # 6 us @array, 30 us @list \w 100 bins r""" Calculate the common part of two histograms. Among the possible methods there is also the CV_COMP_INTERSECT which is an implementation of the histogram intersection method. 3) Example 2: Modify Bins of ggplot2 Histogram. In this article you’ll learn how to change the width of bins of a histogram in the R programming language. minimum is used to compare the values of each bin between the two histograms and take the minimum value. ^2)) You can repeat this for each R, G and B component, and combine the three distances again using the Euclidean norm: Feb 27, 2024 · This code compares histograms using the Chi-Squared method. csv", stringsAsFactors=FALSE) There are several variables including age, salary, and weight, but for the purposes of this tutorial, you’re only interested in height, which is the Ht_inches column. The “intersection” simply represents the elements that the two objects have in common. This is a generic function, extended from the intersect function in the base package. Then just use the respective slopes to find the intercept for that segment. If weights are given, hist. 3) Example 2: Draw Median Line to Histogram Using Base R. Jan 2, 2021 · This tutorial provides a step-by-step example of how to create a histogram of residuals for a regression model in R. Nov 18, 2015 · A histogram was constructed from the results, and it was noted that it was mound-shaped and symmetric, with a sample mean of 65 and a sample standard deviation of 8. The closer the histogram fits this curve, the more (perfectly) normal the sample. Does anybody know if there is a ready-to-use function to calculate the skewness of the distribution from a given histogram? r. The image on the left is our original Doge query. I have applied some of the histogram distance functions for outlier reduction when learning color term/name models from web images Sep 23, 2022 · In this tutorial, you’ll learn how to use the NumPy histogram function to calculate a histogram of a given dataset. The content of the tutorial is structured as follows: 1) Creation of Exemplifying Data. Jun 27, 2018 · I'm working with shapefile in R and I need to calculate the polygons' area that I created by Gdiference function, So ,now I need to create a column with the size of freshly polygons created, because after that I need take out the small polygons which are not important to my academic research. Choose a scale for the vertical axis that will accommodate the class with the highest frequency. 15) Base R hist function uses the Sturges method to calculate the number of bins, which is a good default. 18). mathematical-statistics. , label=. 466224824 5. Simply using the freq=FALSE argument does not give a histogram with percentages, it normalizes the histogram so the total area equals 1. Step 1: Create the Data First, let’s create some fake data to work with: Jun 29, 2021 · It is the index of the channel for which we calculate the histogram. In some researches (for example The Quadratic-Chi Histogram Distance Family) I saw that the formula of Chi-Square distance is: This R tutorial describes how to create a histogram plot using R software and ggplot2 package. e. It returns the comparison metric value. , the bars from 0 to the first black border on the left should be coloured red and the bars in the second region should be coloured green. How do I get a "proportion covered" variable attached to each county in the nc dataframe? This argument controls the width of each bin along the X-axis. Feb 27, 2014 · Assuming you have the R console open, load the CSV file with read. 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). AddValue( some_result ); } Jul 27, 2016 · We present new methods for fast Gaussian process (GP) inference in large-scale scenarios including exact multi-class classification with label regression, hyperparameter optimization, and uncertainty prediction. A histogram is used to count or visualize the frequency of data (i. Hence, in a histogram the x-axis represents the single variable and the y-axis is the estimate of the density of the data at values on the scale of x. 2 * 10. In this tutorial you’ll learn how to draw a mean or median line to a histogram in R programming. In many cases the histogram of an image where foreground and background should be separated is bimodal. Feb 13, 2024 · The histogram is constructed by plotting the bins along the x-axis and the frequencies (or densities) along the y-axis. The y axis is the frequencies, and the x axis is the values in the list. plot_mix_comps <- function(x, mu, sigma, lam) {. Note. I want the bars in the two regions to be coloured red and green respectively, i. Use the OpenCV function cv::split to divide an image into its correspondent planes. 6,0. where: L: The lower limit of the median group; n: The total number of observations Mar 20, 2022 · For example, the circle where the assists and rebounds variables intersect is small and light red, which tells us that the correlation is low and negative. Feb 28, 2024 · Method 4: Advanced Multi-Channel Histogram with cv2. 6),prop=c(0. The threshold Dec 28, 2023 · For the Histogram Formula calculation, we will first need to calculate class width and frequency density, as shown above. calcHist() and plot it with the matplotlib library and how compare two histograms using cv2. This function uses the following basic syntax: Example 2: Plot Cumulative Histogram Using ggplot2 Package. Jan 8, 2013 · Calculate the H-S histogram for all the images and normalize them in order to compare them. histSize Aug 14, 2019 · Here, I demonstrate how to find the point where two histograms overlap. How to plot a Less than type Ogive: In the graph, put the upper limit on the x-axis; Mark the cumulative frequency on the y-axis. This article will show you how to make stunning histograms with R’s ggplot2 library. . csv("nba-players. Now compute the Euclidean distance between the two vectors: DR = norm(R1-R2); % same as sqrt(sum((R1-R2). calcHist can again be utilized. #Create Dataset x <- c (1,1,4,4,9) #Estimate Density d <- density (x) #Two ways to get Nov 29, 2015 · Authors also show a formula of Chi-Square distance: ∑i=1n (xi − yi)2 (xi +yi) ∑ i = 1 n ( x i − y i) 2 ( x i + y i) Where n n is a number of bins, xi x i is a value of first bin, yi y i is a value of second bin. We’ll start with a brief introduction and theory behind histograms, just in case you’re rusty on the subject. Step 1: Create the Data Nov 18, 2021 · By default, the hist() function in R uses Sturges’ Rule to determine how many bins to use in a histogram. For more control over histogram plotting, especially when dealing with multiple image channels, cv2. In R, the function skewness from package moments allows one to calculate the skewness of the distribution from a given sample. You are actually getting a different histogram for each value of seg. Step 2: Count how many data points fall in each bin. You can specify normalization. And, because ratio data is very tightly laid out, the plot will not be too Jan 17, 2023 · One way to visually check this assumption is to create a histogram of the residuals and observe whether or not the distribution follows a “bell-shape” reminiscent of the normal distribution. May 21, 2020 · What I now want to calculate is: what percentage of each of the 100 counties is covered by the circle. Now Feb 18, 2014 · I have a histogram as shown in the picture. Then, I do the following: hist (list, breaks=length (list), freq=TRUE) and it automatically makes the ranges for the x and y axis. Display the numerical matching parameters obtained. 274580708 2. Downloadable code: Click here; Code at Jan 8, 2024 · Histograms provide an excellent graphical display to help us assess normality. library ("ggplot2") # Load ggplot2. Apr 25, 2017 · Use the information you have (histogram, etc) to fit a density estimator for your two candidate functions. compareHist() which take as input the histogram parameters and the comparison method. Jun 9, 2022 · You can use the intersect() function in base R to find the intersection of two objects. You can find the area under the histogram by summing all heights and multiply by the bin width. Learn how to use python api histogram_intersection. Normalize the histograms computed above for the two input images using cv2. 0 to 2pi) # To keep the *relative* value of a and b the same, combine a and b in the. Predict: $\hat y = argmax_{i=1,2}\hat f_{i}(x)$ Jan 5, 2021 · The example code (pasted below) fits a Gaussian Mixed Model (GMM) and clarifies the two distributions. mask : mask image. Draw a line from the right corner of the tallest bar to the right corner of the bar immediately before it. density extends “xlim” beyond the range of my data. Method 3: Intersection. The term was first introduced by Karl Pearson. You can also add a line for the mean using the function geom_vline. Formatting x-axis with histogram in R. Here are all the metrics and formulas that I have found: Chi Square : Formula: x2 = ∑n i=1 (hist1i−hist2i)2 hist1i x 2 = ∑ i = 1 n ( h i 1. density. # Load the data. R software histogram with all printed x Aug 25, 2020 · 1. Draw a line from the left corner of the tallest bar to the left corner of the bar immediately after it. Due to shading this leads to two peaks in the histogram (cf. 2. set. compareHist(). To get a histogram of percentages of some data set, say x, do: Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand Nov 24, 2023 · intersect() function in R Programming Language is used to find the intersection of two Objects. OpenCV provides several built-in methods for histogram comparison as shown below. Distribution means a dataset is divided into “groups” called “bins,” and we assign each data point to one of the groups. Choose how you would like the bins to be labeled. geom_histogram(breaks=breaks,aes(x=vector,y=. Let’s now compute three histograms, one for each channel of the input RGB image: # load the input image from disk. It is essential to use the same from and to values for each data set. By the… Read More »NumPy Histogram: Understanding the np Dec 13, 2015 · My aim is to locate the intersection point, say x and draw two vertical lines at x±k, as abline(v=x-k) and abline(v=x+k) where, k is certain band of tolerance. 0. frame(mod=c(1,2),mean=c(14,16),sd=c(0. 0 * 5 + 0. Less Than Type Cumulative Frequency Curve. Just in case someone hits this question with ggplot's geom_histogram in mind, note that there is a way to extract the data from a ggplot object. I have searched on the internet and have found some metrics that can be used to perform this comparison, for example, Chi Square and Intersection. Hence, Area of the Histogram = 0. Values)*h. The figures on the right contain our results, ranked using the Correlation, Chi-Squared, Intersection, and Hellinger distances, respectively. Returns: hist array. The values of the histogram. 5. 5) answered May 20, 2014 at 21:31. Dec 22, 2022 · To find the mode in a histogram, we can use the following steps: 1. The function geom_histogram() is used. Data points should be comma or space separated. Choose the mode - 'Automatic' or 'Manual'. I specicially made the data sets Jul 14, 2014 · Figure 2: Comparing histograms using OpenCV, Python, and the cv2. In order to use the functions of the ggplot2 package, we first need to install and load ggplot2: install. You’ll then see how to create and tweak ggplot histograms taking them to new heights. 4. frame(x=rnorm(100,5,2)) ggplot(dd, aes(x=x))+ geom_histogram() +. imread(args["image"]) # split the image into its respective channels, then initialize the. Histogram and density plots. In the last tutorial ( Histogram Equalization) we talked about a particular kind of histogram called Image Histogram Intersection $D_{\cap} = 1 - \frac{\sum_{i} \left(\min(h_1(i),h_2(i) \right)}{\min\left(\vert h_1(i)\vert,\vert h_2(i) \vert \right)}$ Cosine Distance Mar 10, 2015 · hist (AirPassengers, breaks=c (100, seq (200,700, 150))) #Make a histogram for the AirPassengers dataset, start at 100 on the x-axis, and from values 200 to 700, make the bins 150 wide. Compare the histogram of the base image with respect to the 2 test histograms, the histogram of the lower half base image and with the same base image histogram. Boxplots with R. May 29, 2009 · 10. #roi is the object or region of object we need to find. Histograms have many applications within data and image processing. seed(15) dd<-data. The proposed measure has the advantage over the traditional distance measures A histogram is a visual representation of the distribution of quantitative data. histogram. 9,0. Syntax: intersect (x, y) Parameters:x and y: Objects with the sequence of items. Therefore, we will get a 1 x 10 array of similarity measures through histogram intersection. Next, click the PivotTable Analyze tab, then click the icon called PivotChart: In the new window that appears, choose Clustered Column as the chart type and then click OK: The following chart will appear: The blue bars display the frequency of exam scores for the Females and the orange bars display the Oct 30, 2013 · Viewed 17k times. csv(). Since now, I know how to obtain it using cv2. ), geom="text", vjust=-. density : bool, optional If False, the result will contain the number of samples in each bin. Histogram intersection measures the overlap between the histograms. Apr 20, 2017 · Just find all points where x1 is above x2, and then below it on the next point, or vice-versa. stat_bin(aes(y=. Jan 11, 2014 · 9. np. The elements of intersect(x,y) are those elements in x and in y. Using our Histogram Calculator is straightforward: Enter your data into the input field. Feb 12, 2021 · You'd need to implement the histogram calculation using lists, dictionaries or any other standard Python data structure, if you explicitly don't want to have NumPy as some kind of import. I didn't use any function yet. We propose a distance between sets of measurement values as a measure of dissimilarity of two histograms. You can add a stat_bin to do the calculations of counts for you, and then use those values for the labels and heights. First a bar chart. By examining the histogram, you can gain insights into the distribution of the data. In computer vision, for example, it is used to evaluate the degree of similarity between two histograms. BinWidth; To get a histogram with the total area equal to 1. 3. Dec 2, 2022 · Calculate the histograms of the two input images using cv2. A histogram shows the frequency of numerical data in bins of grouped ranges. The smaller the Chi-Squared value, the better the match between the histograms. a <- rnorm(100) b <- rnorm(100, 2) # To use overplapTrue(){overlap} the scale must be in radian (i. 3% 6. What is a histogram? A histogram is a graphical representation of the distribution of a variable. The assumption here is that the foreground and background both have one characteristic intensity value. imread ( 'rose_red. For image histograms , you basically need to count intensity occurences, most of the time these are values in the range of 0 255 (when dealing with 8-bit Apr 28, 2021 · We only need a single argument, --image, the path to our input image residing on disk. import numpy as np. The answer should be called something like this: Histogram my_hist = new Histogram(); for( uint i = 0; i < NUMBER_OF_RESULTS; i++ ) {. Fig. So, the Area of the Histogram will be –. Each bin is represented by a bar, and the height of the bar corresponds to the frequency of data points in that bin. Our methods are based on exploiting generalized histogram intersection Aug 14, 2019 · To find the point of intersection, I first binned the data sets using density. roi = cv. How to change xlim in ggplot. compareHist function. If you choose 'Manual', fill in the additional parameters. If you do this step correctly, your values should add up to 100% (or 1 as a decimal): Step 4: Draw an Cartesian plane (x-y graph) with percent cumulative relative frequency on the y-axis (from 0 to 100%, or as a decimal, 0 to 1). ) Graph 2. If you don't need the colours, you could use this: ggplot(df) +. I have a list of values. Here's an example. Compare these normalized histograms using cv2. Frequency. The density function creates 512 bins, thus, providing the same starting and ending parameters makes density use the same bins for each data set. Construct bars for each class. In this example, we will create a histogram of the frequency of pixel values within a 256-bit image. By using NumPy to calculate histograms, you can easily calculate and access the frequencies (relative or absolute) of different values. cv2. If we go from 0 to 250 using bins with a width of 50 , we can fit all of the data in 5 bins. This function takes two objects like Vectors, Dataframes, etc. However, in practice, it’s often easier to just use ggplot because the options for qplot can be more confusing to use. the number of occurrences) over units of discrete intervals, called bins. Note that this argument overrides the bin argument. In order to calculate the overlap, the bin edges of the two histograms must be the same. 2: Relative Frequency Histogram for Monthly Rent. 2 * 5 + 3. The qplot function is supposed make the same graphs as ggplot, but with a simpler syntax. Think of a histogram as a vector (maybe there are 256 bins, so it’s a 256-dimensional vector). myHist. Sep 6, 2021 · R does a number of things by default in creating a histogram You can print out this parameters of the histogram by assigning to an an objec histinfo and then printing: breaks will give you the bin width: Step 3: Add a fifth column and cumulate the relative frequencies from column 3. compareHist() too. packages("ggplot2") # Install ggplot2 package. Create the Ogive by plotting the point corresponding to the cumulative Dec 23, 2016 · OK, so you are just struggling with the fact that density goes beyond "natural range". Identify the tallest bar. import cv2 as cvfrom matplotlib import pyplot as plt. How can I plot the confidence intervals on the histogram, as in the Photoshopped image Aug 3, 2018 · Bimodal Histograms – Intersection of Gaussians. The original definition is preserved in the case that x and y are vectors of the same mode. fill=seg results in grouping. binwidth = 0. Finally, we calculate the number of data points in each group and plot them as a bar graph. 15. [1] To construct a histogram, the first step is to "bin" (or "bucket") the range of values— divide the entire range of values into a series of intervals—and then count how many values fall into each interval. Feb 6, 2021 · The class boundaries are plotted on the horizontal axis and the relative frequencies are plotted on the vertical axis. Here we will demonstrate layering histograms for a sleeker visualization, using transparency to simultaneously depict multiple color distributions. type: type of relative frequency histogram you’d like to create; options include percent, count, and density. This can be done in two lines of code in Python, R, etc. While this is an approximation, it seems to have a very high level of precision. Suppose we have the following data frame that shows the points scored by basketball players on various teams: Apr 6, 2020 · This tutorial explains how to create a relative frequency histogram in R by using the histogram () function from the lattice, which uses the following syntax: histogram (x, type) where: x: data. This tutorial provides a step-by-step example of how to create a histogram of residuals for a regression model in R. The final step was to find where the density of the Cumulative frequency is defined as the sum of all the previous frequencies up to the current point. This has a many options that give you control of bin sizes, range, etc. However this metric treats all variables as they were isolated among each other; in other words if the histograms had 8 Jan 17, 2023 · By looking at the histogram, this seems like a reasonable estimate of the mean. 6. library("mixtools") #Define function. Can this be done in R? The code used to get the histogram is R histogram plot controlling x-axis values. Prepare simulated data I created two data sets, gamma_dist and norm_dist, which are made up of a different number of values sampled randomly from a gamma distribution and normal distribution, respectively. The following table shows how to calculate the midpoint of each class: Class. Jan 19, 2019 · Draw a vertical line just to the left of the lowest class. Notice the shape is the same as the frequency distribution. png') Dec 24, 2014 · In your case, A would be a single column which denotes the histogram of your query image. bin_edges array of Learn more about Bar Graphs and Histogram here in detail. Sturges’ Rule uses the following formula to determine the optimal number of bins to use in a histogram: Sep 5, 2018 · The following data, represent 2 given histograms split into 13 bins: key 0 1-9 10-18 19-27 28-36 37-45 46-54 55-63 64-72 73-81 82-90 91-99 100 A 1. Tip study the changes in the y-axis thoroughly when you experiment with the numbers used in the seq argument! Note that the different width of the bars or bins Here's how to make a histogram of this data: Step 1: Decide on the width of each bin. I'm trying to get the maximum frequency on a histogram graph. The package comes with an example of color image matching (although this might not be the best application idea, imho; anyway, it showcases the code). 7 * 10 + 4. 4) Example 3: Draw Mean Line to Histogram Using ggplot2 Jun 11, 2022 · Example: Calculate Percentage by Group in R. 2) Example 1: Draw Mean Line to Histogram Using Base R. The numpy function np. 4 * 5 + 0. x = rand (1000,1); h = histogram (x); area = sum (h. In contrast to previous approaches, we use a full Gaussian process model without sparse approximation techniques. lam * dnorm(x, mu, sigma) } #Example with `faithful` dataset. You can easily create a histogram in R using the hist () function in base R. 1. May 7, 2020 · Open in MATLAB Online. Theme. Label the marks so that the scale is clear and give a name to the vertical axis. In Example 2, I’ll show how to plot a cumulative histogram using the ggplot2 package. Nov 10, 2014 · Two of the most famous approaches to compare 2 normalized histogram Qi Q i and Pi P i where i i is the bin number i = 1: d i = 1: d are as followed: Histogram Intersection sIS = ∑i min(Pi,Qi) s I S = ∑ i m i n ( P i, Q i) ChebyChev X2 dsq−chi = ∑i (Pi−Qi)2 (Pi+Qi) d s q − c h i = ∑ i ( P i − Q i) 2 ( P i + Q i) where 1 is a Mar 4, 2020 · 41 – 50. Approximately what proportion of ratings would be above 81? I have answered it manually with this : Pr (X>81)=Pr (Z> (81-65)/8)=Pr (Z>2)=0. as arguments and results in a third object with the common data of both objects. Example 4: The corrplot Function. geom_density(aes(x=vector,y=. Jan 17, 2023 · Step 3: Overlay Two Histograms in Plot. 4)) With the mean and standard deviation of my 2 curves, and prop the proportions of contribution of each mod to the You simply have to rescale your data so that it range from 0 to 2π. Well, just set cut = 0. Nov 16, 2021 · Scatter Plots with R. To find the popularity of the given data or the likelihood of the data that fall within the certain frequency range, Ogive curve helps in finding those details accurately. count. Here we use the upper limit of the classes to plot the curve. These are the intersection points. To calculate histograms of arrays of images by using the OpenCV function cv::calcHist. Copy. The answer of chthonicdaemon is close to the peak, but each diff is reducing the vector length by one. A distance measure between two histograms has applications in feature selection, image indexing and retrieval, pattern classication andclustering, etc. The following convenience function outputs a dataframe with the lower limit of each bin (xmin), the upper limit of each bin (xmax), the mid-point of each bin (x), as well as the frequency value (y). A histogram is a crude estimate of the probability density function of a univariate (in the conventional sense of a histogram) variable. For exemple : # simulate two sample. You can also use ggplot. One of the ways to measure the similarity of two discrete probability distributions is the Bhattacharyya distance. )) Jan 8, 2013 · First we need to calculate the color histogram of both the object we need to find (let it be 'M') and the image where we are going to search (let it be 'I'). Finding Peaks in density functions is, as already given in the comments, related to Finding local maxima and minima where you can find more solutions. 2. To find the histogram of the full image, it is given as “None”. normalize(). How to Estimate the Median of a Histogram. May 20, 2014 · 26. dtype will be taken from weights. B would be a 10 column matrix that denotes the histograms for each of the database images. calcHist(). There is no strict rule on how many bins to use—we just avoid using too few or too many bins. We can use the ggcorrplot() function from the ggcorrplot package in R to visualize the correlation matrix: Details. Our calculator will automatically generate the histogram 4. Therefore, the Area of the Histogram = 47 children. Numpy does not have a built-in function for comparing histograms Aug 13, 2019 · OpenCV provides a builtin function for comparing the histograms as shown below. compareHist(H1, H2, method) Here, H1 and H2 are the histograms we want to compare and the “method” argument specifies the comparison method. We can add a “normal curve” to the histogram which shows the normal distribution having the same mean and standard deviation as our sample. May 10, 2013 · - (Histogram) Intersection - (Histogram) Match - Quadratic form. players <- read. 4) Video, Further Resources & Summary. 5) Binwidth of 0. You can find the midpoint of each class by adding the lower class limit and the upper class limit, then dividing by two: Class midpoint = (lower class limit + upper class limit) / 2. Binwidth of 0. vp pa fm mx jg tp xp rc ga zt