How do I create a 3D histogram for; x = 126, y=128, z = 26*28 ?

49 次查看（过去 30 天）

显示更早的评论

Aaron Rampersad 2016-3-21

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/274707-how-do-i-create-a-3d-histogram-for-x-1-26-y-1-28-z-26-28

移动：Rik ，2023-4-14

I would basically like to bin the the 'z' data into ranges of x and y such as the attached picture:

2 个评论
显示 1更早的评论隐藏 1更早的评论

Aaron Rampersad 2016-3-22

http://www.mathworks.com/matlabcentral/fileexchange/1420-scatterbar3

I used this code from filexchange but I ended up with a very dense plot attached below:

What I would like to do is place these z-values which is a 26*28 matrix into bins associated with the x and y values

请先登录，再进行评论。

请先登录，再回答此问题。

回答（3 个）

Walter Roberson 2016-3-21

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/274707-how-do-i-create-a-3d-histogram-for-x-1-26-y-1-28-z-26-28#answer_214495

http://www.mathworks.com/help/stats/hist3.html

http://www.mathworks.com/help/matlab/ref/bar3.html

There are also a lot of histogram programs in the File Exchange.

2 个评论
显示 1更早的评论隐藏 1更早的评论

Walter Roberson 2016-3-21

Do you need zooming and data tips? If not then see http://www.mathworks.com/matlabcentral/fileexchange/35274-matlab-plot-gallery-bar-graph-3d

If you do, then see for example http://www.mathworks.com/matlabcentral/fileexchange/45916-3d-colored-bar-plot

请先登录，再进行评论。

Image Analyst 2016-3-22

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/274707-how-do-i-create-a-3d-histogram-for-x-1-26-y-1-28-z-26-28#answer_214525

Aaron, give the x and y data as an N by 2 array, then pass in the number of bins in each direction into the poorly named hist3() to create your 2D histogram

counts = hist3([x, y], [26, 28]);

8 个评论
显示 7更早的评论隐藏 7更早的评论

Image Analyst 2016-3-22

编辑：Image Analyst 2016-3-22

OK, "Contribution to Hazard" is a count. The count you get from a certain "Source to Site Distance" range, and from a certain "Magnitude" range. So like I said, you can pass "Source to Site Distance" and "Magnitude" into hist3() and get out the counts ("Contribution to Hazard") for those observations that fall into both ranges. The counts will be your "z" values and is represented by the heights of the bars.

I don't know what you mean by clusters. I see no clusters, or many just one big one that is essentially the whole hump. (Did you perhaps mean clutter instead?) If you want fewer bins (vertical columns/bars), then just pass in the number of bins in each direction you want to hist3() and it will make a histogram with that many bars. You can also change the bar width to make it more solid and without empty "air space" between the bars, if you want.

I see from Mike's answer that they now have a histogram2() which seems like it does what hist3() did but with a much more appropriate and descriptive name.

Image Analyst 2016-3-26

Well now you'r totally confusing everybody. We though that the x and y were basically ranges that your data could take. So one data point had both an x coordinate, and a y coordinate. And you wanted 28 bins along the y direction, and 26 bins along the x direction. And then "z" would be the counts of how many data points fell into a certain x,y bins. You don't have any z data yet, before taking the histogram, do you? It's to be computed and is the "count" data. If that's not right, then no one has read your mind correctly, and you'll need to explain better and attach your x, y, and z arrays.

请先登录，再进行评论。

Mike Garrity 2016-3-22

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/274707-how-do-i-create-a-3d-histogram-for-x-1-26-y-1-28-z-26-28#answer_214582

If you're using R2015b or later, you can use the new histogram2 function.

histogram2(10+5*randn(1e4,1),3*randn(1e4,1),'FaceColor','flat')

13 个评论
显示 12更早的评论隐藏 12更早的评论

Image Analyst 2023-4-11

移动：Rik 2023-4-14

You don't need the toolbox to run scatteredInterpolant. You can run it on just a regular 2-D matrix. Here is the main part:

%================================ MAIN PART RIGHT HERE ==============================================
% Create the scattered interpolant. x, y, and gray levels must be column vectors so use (:) to make them column vectors.
% And grayLevels must be double or else an error gets thrown.
F = scatteredInterpolant(xAll(:), yAll(:), double(grayLevelsAll(:)))
% The above line creates an interpolant that fits a surface of the form v = F(x,y).
% Vectors x and y specify the (x,y) coordinates of the sample points.
% v is a vector that contains the sample values associated with the points (x,y).
% Get a grid of points at every pixel location in the RGB image.
[xGrid, yGrid] = meshgrid(1:columns, 1:rows);
xq = xGrid(:);
yq = yGrid(:);
% Evaluate the interpolant at query locations (xq,yq).
vq = F(xq, yq);
fittedImage = reshape(vq, rows, columns);
%================================ END OF MAIN PART ==============================================