I have to make a plot in which the X and Y axis are between 0.5 and 1, and the values of Y are always less than the values of X. This is somehow a portion of a square, like this
So I am not using the entire square. I would like to do in Matlab something like this
I mean, making the plot like a triangular shape. Do you know how I could do it in Matlab?
Thank you
Related
I have a 3D data, the x and y axis are angles and the Z axis is output. so the data is like this: [angle1 x angle2 x Z] ... I have multiple Z values at different conditions as well. Let's assume different Z values for 10 different conditions.
I want to plot a 3D contour of all the Z values overlaid on top of each other and at the same time fill the areas of each contour where Z<=-1 with a desired color ... How is that possible in MATLAB?
I found a way to overlay all the Z values on top of each other using a single color and contour command but I cannot find any way to fill the areas of Z<=-1 ... I realized that in contour command, MATLAB actually fill the whole graph with colors, so "hold on" command does not work here!
Here is an example image I want to create
Below is the example I could create but I cannot create the colored plot
I think this might be simple. If we simply plot a vector in MATLAB, it will show it normally, going left to right. That is, the x-axis will have 'time'.
But, I would like to show it going from up to down instead in the plot. How can I do that? In other words, I want the amplitude to be shown on the x-axis, and the time to be shown on the y-axis.
Thanks.
Create a vector with the coordinates of your time vector t and flip x and y in your call to plot:
plot(t, 1:length(t));
This question entails rotating an image given as a 3D matrix where the first dimension is width, 2nd dimension is height, and 3rd dimension contains x,y,z coordinates.
Currently I am plotting a surface using the following code
Fig.sub1im=surf(ToFparam.ROI.XYZ(:,:,1),ToFparam.ROI.XYZ(:,:,2),ToFparam.ROI.XYZ(:,:,3),zeros(ToFparam.ROI.height,ToFparam.ROI.width,3));
Now, I have a 3-D matrix where it's a 100x50x3. All x data is in the first...page or layer of the 3rd dimension, y is the second layer...z the third. Now I need to apply a 3x3 rotation matrix on the x y and z data. I know how to reshape a matrix to do this I think....just put it into a 3 row by...50000 column matrix then apply the matrix.
Next I need to update my plot in a loop. I was going to then do the following, where I have also included my new matrix calculation.
ToFparam.ROI.XYZ_Vector = ToFparam.ROI.XYZ;
ToFparam.ROI.XYZ_Vector = reshape(ToFparam.ROI.XYZ, [size(ToFparam.ROI.XYZ,1)*size(ToFparam.ROI.XYZ,2),3]);
ToFparam.ROI.XYZ_Vector = ToFparam.ROI.XYZ_Vector';
ToFparam.ROI.XYZ_DICOM = inv(DICOMparam.calib.navi2dicom(1:3,1:3))*inv(Naviparam.data.Endo_RefHomMat(1:3,1:3))*ToFparam.ROI.XYZ_Vector;
%refresh plot standard cuts
set(Fig.sub1im,'CData', Color);
set(Fig.sub1im, 'XData', ToFparam.ROI.XYZ_DICOM(1,:) + DICOMPos(1)/Fig.sub2samp);
set(Fig.sub1im, 'YData', ToFparam.ROI.XYZ_DICOM(2,:) + DICOMPos(2)/Fig.sub2samp);
set(Fig.sub1im, 'ZData', ToFparam.ROI.XYZ_DICOM(3,:) + DICOMPos(3)/Fig.sub2samp);
When I update my plot, I get no errors, but it doesn't look like it's plotting it correctly. It seems like it makes a huge offset on my data and positions it somewhere I don't want it to be positioned. I wouldn't expect that a rotation matrix effects the scaling, just the orientation. Let me know if there are any faster/better ways to accomplish this surf plot, thanks!
For anyone interested, I have found the solution.
If you ever want to rotate a 3-D matrix where the x,y,z data is located in the 3rd dimension, use the following for maximum speed and efficiency.
[m,n,z]=size(inMatrix);
outMatrix=reshape((A*(reshape(double(inMatrix),[m*n 3]))')',[m n 3]);
Where inMatrix is your initial 3d matrix, outMatrix is your output 3d matrix, and A is your rotation matrix. Can be extremely useful when wanting to code rotations in images, since images will have 2 dimensions along their width and height, and the 3rd dimension will be the x, y and z coordinates. This will allow you to easily plot an initial data set, rotate it, then replot it.
I have 2 vectors, one call X and enother calls Y.
In X I have the x coordinate, and in Y the y coordinates.
The first coordinate in X and the first in Y give a point, and so on..
The numbers in each vectors are float, and can be negative and positive.(-29.3, 14.2)
If I make plot on them I'm getting a green square.
plot(X,Y,'g');
What I want is to turn both vectors into 1 matrix, and if I will do imshow(Matrix)
I will get the same square image.
Doing this:
Matrix = [X;Y;];
Didn't work. It just draw somthing green on the screen.
Hope I was clear enough.
Thanks All!
Shlomi, you need to use hist3.
For example:
m=hist3([X' Y'],nbins)
just select the number of bins nbins appropriately so you'll have the grid resolution you want. Then imshow(m) will work.
I am looking for help for my particular problem.
I have a contour plot created from XYZ data. This plot contains 2 broad peaks with one more intense than the other.
When the most intense peak is aligned with the Y axis, I can perform a fitting of every YZ curve at each X values. I usually do a gaussian fit to plot the peak center on the same graph.
In some cases I need to perform the same fitting but no along the Y axis direction (in this case I just plot YZ scan at every different X values) but along another arbitrary direction.
For the moment the only way I found is the following:
-plot the contour plot and find for the position of the most intense peak
-if the position is not aligned with the Y axis, then rotate all the datas and plot again the contour
-perform the YZ gaussian fit for every X value
- Rotate the resulting XY position to go back to the original plot
-plot the XY position as a line on the original contour plot
this is quite long and requires a lot of memory. i would like ot know if there is a more elegant/faster way.
Thanks for your help
David
I take it you want to extract data from the (x,y,z) data along some arbitrary line in order to make a fit. A contour plot will show only part of the data, the full z(x,y) data can be shown with imagesc etc. Say you want the data along line defined by two points (x1,y1) -> (x2,y2). According to the eq of the line, the line y=a*x+b the slope a is (y2-y1)/(x2-x1) and b=y1-a*x1. For example, I'll select (x,y) coordinates in the following contour:
Create data and end points:
m=peaks(100);
x1=11 ; x2=97;
y1=66; y2=40;
Thus the line parameters are:
a=(y2-y1)/(x2-x1);
b=y1-a*x1;
and the line is:
x=x1:x2;
y=round(a*x+b);
select the proper (x,y) elements using linear indexing:
ind=sub2ind(size(m),y,x)
plot:
subplot(2,1,1)
contour(m,10); hold on
line([x1 x2],[y1 y2],'Color',[1 0 0]);
subplot(2,1,2)
plot(m(ind))
You can now use vec=m(ind) to fit your function.