contour plot not working because of duplicate value

Hello Everybody

I have 3 vectors with 95000 rows. X, Y,and T(time of rupture). Now I need to draw contour using these 3 vectors.but it sounds there are duplicates data(an error message say so! I guess there might be some data with same X and Y ) . I would like to removes them before drawing contour plot. Can anyone help. Thank You for your time.

Answer 1

[Varun Garg]

Hi Samaneh,

My understanding of your question is that for the vectors X and Y you want to find values which are common in both.

For that you can use

intersect

Example snippet:

x=[1 2 3 4 5 10 20 30];
y=[4 5 10 100 90 22 33];

[z ix iy]= intersect(x,y)

x(ix)=[]
y(iy)=[]

Hope my understanding was right. You can refer documentation here .

[Samaneh Arzpeima]

Thank you, Varun. The X, Y are the coordinates of a meshed surface and I want to plot the contour of the slip(or time of the slip) for those nodes. But I get an error says that there are some overlapped data. So I think I should have some grids with the same coordinates(same X and Y) , I need to find those rows and delete them.(rows with the same X and Ys and delete the whole row.) I have the coordinates data down to 8 decimal.

*your code didn’t work on MtlanOnline The error was Error in intersect>intersectR2012a (line 220) [c,iau] = unique([a(ia) b([])],order);

Error in intersect (line 111) [varargout{1:nlhs}] = intersectR2012a(varargin{:});

Error in unique (line 8) [z ix iy]= intersect(x,y)

[Varun Garg]

I am trying to imagine it. So basically X and Y are vectors only but they make up a coordinate system with let's say X(1) and X(1) correspond to a point in 2-d plane?

[Samaneh Arzpeima]

exactly X(1) and Y(1) correspond to one point.

[Varun Garg]

So what I gather from the information provided is that the mesh can be though of as an AxB matrix let's say M. And if there is a point X(i),Y(i) which can be thought of as M(j,k), if both of the coordinates are same, you want to remover the whole row j?

[Samaneh Arzpeima]

vector1

X=rand(90000,1)

vector2

Y=rand(90000,1)

vector3

T=rand(90000,1)

here,point(X,Y) refers to a grid coordinate,

if

X(i,1)=X(j,1)=X(k,1)...

Y(i,1)=Y(j,1)=Y(k,1)...

I need to keep just one of the repeated grid point,for example keep the row(i), and delete row(j) and (k).when I have same grid data even with different T.

-------------------------------

what I actually have

vector1 d.X 90000*1 coordinat

vector2 d.Y 90000*1 coordinat

vector3 d.Dz 90000*1 time of slip for each grid

I wrote something like this to get the graph that I attached here, I ignored the repeated data point for this graph though.

scatter(d.Y,d.X,5,d.Dz);

[X,Y] = meshgrid(linspace(min(d.Y),max(d.Y),80), linspace(min(d.X),max(d.X),80));

hold on

[C,h]=contour(X,Y,griddata(d.Y,d.X,d.Dz,X,Y),[10 8 6 4 1 ])

I want to delete the repeated data and replot

if I am not clear ,excuse me,and just ignor.sorry for the time

[Samaneh Arzpeima]

@Varun Garg sorry if I made it complicated ,I am still new in Matlab

[Varun Garg]

It has become a bit confusing. Let me tell you final understanding of your question:

Mathematically, you have a function

f(x,y,t).

And let's say you have two points on the 3-D Plane

f(xi,yi,ti) and f(xj,yj,tj).

If

f(xi,yi,ti) == f(xj,yj,tj)

you want to remove either

f(xi,yi,ti) or f(xj,yj,tj).

Is that so?

[Samaneh Arzpeima]

I just rewrite my last question ,it might be a bit more understandable. (^^;)

[Samaneh Arzpeima]

vector1

X=rand(90000,1)

vector2

Y=rand(90000,1)

vector3

T=rand(90000,1)

here,point(X,Y) refers to a grid coordinate,

if

X(i,1)=X(j,1)=X(k,1)...

Y(i,1)=Y(j,1)=Y(k,1)...

I need to keep just one of the repeated grid point,for example keep the row(i), and delete row(j) and (k).when I have same grid data even with different T.

-------------------------------

what I actually have

vector1 d.X 90000*1 coordinat

vector2 d.Y 90000*1 coordinat

vector3 d.Dz 90000*1 time of slip for each grid

I wrote something like this to get the graph that I attached here, I ignored the repeated data point for this graph though.

scatter(d.Y,d.X,5,d.Dz);

[X,Y] = meshgrid(linspace(min(d.Y),max(d.Y),80), linspace(min(d.X),max(d.X),80));

hold on

[C,h]=contour(X,Y,griddata(d.Y,d.X,d.Dz,X,Y),[10 8 6 4 1 ])

I want to delete the repeated data and replot

if I am not clear ,excuse me,and just ignor.sorry for the time

[Varun Garg]

Okay. That's a bit better explanation. One more doubt If

X(i,1)=X(j,1)=X(k,1)

and

Y(i,1)=Y(j,1)=Y(k,1)

Should they both hold true together for me to keep only i row and delete j,k.. Or any of (1) or (2) hold true, I should delete j,k.. from both X and Y?

[Samaneh Arzpeima]

Thamk you again

I just need one set of (x,y) to have one value of time or slip. for a point with coordinate lets say (x=2,y=3) if I have 3 value for time like

x y t

2 3 3

2 3 2

2 3 5

I want to keep point(2,3) with the lowest time, so I have to delete first and third row.