Correcting the label in a 3D scatter plot

2020 4 26
2 个回答
回答已采纳
更新时间：2020 4 27
10 次查看（30 天）

0 个投票

Hello there,
I have a .xls file that contains x,y,z vertics. The sequence goes something like this (that header of each): x0,y0,z0,x1,y2,z2,..........x1000,y1000,z1000. (3000points in total) Each x,y,z together forms a point I see in the scatter 3D point. I am wondering how to identity/access that particular point properly, say x0,y0,z0 will be verticx 0, x1000,y1000,z1000 will be verticx 1000.
That's what I have from the help eailer:
clc;clear all;
[num,txt,raw] = xlsread('test_april24.csv');
for i = 1:3:3000
a = num(3,i);
b = num(3,i+1);
c = num(3,i+2);
k=scatter3(a,b,c, 'filled');
S=string(1:3000).';
text(a, b, c, S);
row = dataTipTextRow('Index: ',i');
k.DataTipTemplate.DataTipRows(end+1) = row;
hold on
end
The index number is now just showing one of the axis (since its based on the total number i) say index 3000 but I am expecting 1000
In addition, when the index popped up, is there a way that I can access a participant point that I am interested? say x100,y100,z100 (verticx100)?
Many thanks!

5 个评论
显示 3更早的评论 隐藏 3更早的评论

Image Analyst
Image Analyst 2020-4-26
You forgot to attach 'test_april24.csv'. Make it easy for us to help you.
darova
darova 2020-4-26
Can't run the script
steamrice
steamrice 2020-4-26
I attached that and hope that I illsutated what i was trying to achieve! Thanks for your time
steamrice
steamrice 2020-4-26
Sorry I uploaded the .csv one now
steamrice
steamrice 2020-4-26
Are you able to open that? @darova
Thanks

请先登录，再进行评论。

请先登录，再回答此问题。

 采纳的回答

darova
darova 2020-4-27

1 个投票

I used currentPoint property of callback to get coordinates of mouseclick
currentPoint returns 2 points in 3D space. I used crossp roduct to find closest point
See script inside

8 个评论
显示 6更早的评论 隐藏 6更早的评论

steamrice
steamrice 2020-4-27
编辑：steamrice 2020-4-27
Thanks for the response! I am wondering should I keep what I had or just call your function directly after my for loop? Beacause I would need to read my excel file first
darova
darova 2020-4-27
Use this function after for loop.
steamrice
steamrice 2020-4-27
Thanks for the response! I saw those 10 random points plotted together on my data and it pops with the corresponding vertex (vertex 1 to vertex 10). However, I am trying to acheive the proper indexing on the original data (corresponding to the excel file header)?
darova
darova 2020-4-27
I copied 3d row of excel file into text file
Put this part inside the script
a = load('data.txt');
n = fix(length(a)/3)*3;
x = a(1:3:n);
y = a(2:3:n);
z = a(3:3:n);
h = plot3(x,y,z,'.r');
axis vis3d
steamrice
steamrice 2020-4-27
Wow! Thats what I am trying to achieve! I am trying to replace the x,y,z =rand(10,1) with you mentioned above and it worked!
So did you just tried to copy the .csv file into a text file directly? (without the header)
darova
darova 2020-4-27
I couldn't import data from excel file. So i just saved some as txt
steamrice
steamrice 2020-4-27
No problem! Thanks for the suggestions here.
That's what I was trying to achieve there. If you don't mind ask a follow up question, is the vertex that I see here corresponding to the header of the excel? I am wondering is there a way for me to verifiy this? Like if click vertex 1, would it be able to show its x,y,z component so I can go back to the excel/ text file to verfiy that?
darova
darova 2020-4-27
Sure. Go inside callback function and add this line
% line(x(ix),y(ix),z(ix),'marker','*')
[x(ix) y(ix) z(ix)]

请先登录，再进行评论。

更多回答（1 个）

Image Analyst
Image Analyst 2020-4-27

1 个投票

If you want vertex 100, just use that index to get the x, y, and z values:
x100 = x(100);
y100 = y(100);
z100 = z(100);

7 个评论
显示 5更早的评论 隐藏 5更早的评论

steamrice
steamrice 2020-4-27
Thanks for the response! I am trying that! But also the other question I had was is it possbile to show x0,y0,z0 as index 0 rather than a column number? The current situaition is that the index is only referring to one of the axises, which I will have to go back to the excel to check the column number...
Image Analyst
Image Analyst 2020-4-27
Not sure what that means. There is no row zero or index zero in a matrix. In MATLAB all matrices start with row 1 and column 1. So I assume x0,y0,z0 are all in index 1, so what's wrong with saying
x0 = x(1);
y0 = y(1);
z0 = z(1);
steamrice
steamrice 2020-4-27
Sorry for not being clear. I mean I would like to match the index I see in the plot to the excel header. Say x0,y0,z0, I would hope it corresponds to index 0 rather than a column number, say 5...
Image Analyst
Image Analyst 2020-4-27
Still not sure what you mean. MATLAB uses 1-based arays, not 0-based arrays like C++. See the FAQ: FAQ #22 Subscript_indices_must_either_be_real_positive_integers_or_logicals
steamrice
steamrice 2020-4-27
Thanks for response! I think maybe attaching an image might help here
I was testing with these two lines, txt is 1x3000 index and I tried to convert it to 3000x1 string. They are the header you'd see in the excel file ("v0_x", "v0_y", "v0_z" ..."v3000_x", "v3000_y", "v3000_z" 0
index=string(txt.');
row = dataTipTextRow('Index: ',index);
The problem I am having and wanting to achieve, as you can see in the picture, is the index is not showing it properly. The two points that I click, they both showed v0x (in fact, as of now, all points is v0x becase of the above code). I want to have the index properly corresponds to its x,y,z component (matching the excel file).
steamrice
steamrice 2020-4-27
Does that mean more sense.. Thanks!
Image Analyst
Image Analyst 2020-4-27
No, but it looks like darova figured out what you want and solved it because you accepted his/her answer.

请先登录，再进行评论。

类别

在 帮助中心 和 File Exchange 中查找有关 Data Import from MATLAB 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by