Due to my limited knowledge in Matlab i am struggling to plot mean of medians on the image coordinates. I have a gray scale image in Matlab. I want to plot its mean of the medians of its columns on that image so that it divides the image into two parts horizontally. I have obtained mean by using Matlab's 'Mean' command. But i am struggling to get image coordinates where i can plot the mean of medians.
After slight modification in Marcin's code i was able to get this output which shows median of columns of a grayscale image.
The modified code is,
load clown
M = median(X, 1);
figure();
imshow(uint8(X)); one=zeros(1,numel(M));
hold on;
for columnIdx = 1:numel(M)
medianValue = M(columnIdx);
% find locations of gray-scale lavel values equal to the median
idx = find(X(:, columnIdx) == medianValue);
selectone=floor(length(idx)/2); % selecting the middle value
% create a vector containing median values for each column
if (isempty(idx) == 1);
one(1,columnIdx)=svone;
else
one(1,columnIdx)=idx(selectone);
end
% in case when median value doesn't matches columns values use the
% previous column median value
svone=one(1,columnIdx);
end
plot(1:numel(M), one, '-g');
The output is,
I want to plot the mean of the medians of the columns so that it should divide the image horizontally in two parts. Can anyone help me in this or give an idea about it!
So if i understand you correctly, you want to plot another line in that figure over the same xrange as the green line, just with a constant y-value. That constant value shall be the mean of the y-values of the green line, this can be done with line or plot where we just need to define start and ending point:
plot([1, numel(M)], [mean(one), mean(one)], 'r-')
Related
I use the tiledlayout(2,2) command to create a plot in Matlab. The first three title fields filled with normal plots. The fourth and last field is a field with an image. I used the commands IMG = 'mypic.tif'and imshow(IMG).I wonder why I can not change the size of my image. Is this not possible with the tiledlayoutcommand? I have looked up the documentary for tiledlayout and imshow(), but found nothing which helps me.
It indeed seems as if this is not possible using the tiledlayout functionality. However, it is possible using the subplot functionality. Below, I will give an example how this works.
Consider the following script:
% Generate some dummy data for the four plots
x = linspace(0, 2*pi, 25);
y = sin(x);
% Load sample image
image = imread('ngc6543a.jpg');
% Generate the figure
fig = figure(1);
% The three subplots
for i = 1:3
subplot(2,2,i);
plot(x, y);
end
% The image
subplot(2,2,4);
imshow(image);
% Increase size of the image
size_factor = 1.4; % 1.0 is original size
im_ax = fig.Children(1); % axes belonging to image
dims = im_ax.Position(3:4); % current dimensions
dims_new = size_factor * dims; % scale old dimensions
dxdy = (dims_new - dims) / 2; % offset for left bottom corner of image
im_ax.Position = [im_ax.Position(1:2) - dxdy, dims_new]; % update position
In this script, we start by generating some dummy data for the three 'normal' plots and loading a sample image (this image came with my MATLAB installation). Subsequently, we create a figure. After the figure has been created, I add the three dummy plots to the figure using a for loop and the subplot functionality. Then, we plot the image using imshow in the fourth subplot.
Now, the interesting part begins. First of all, I define a scale factor for the image (size_factor). Then, I retrieve the axes in which the image is plotted and store it in im_ax. From this axes, I retrieve the last two elements of the Position field and store them in dims. These two elements define the size of the axes. Based on the value of size_factor, I calculate the new size of the axes and store this in dims_new. To ensure that the axes (and thus the image) remains centered, we need to calculate by how much we need to shift the left bottom corner of the axes (whose coordinates are stored in the first two elements of the Position field). This result is stored in dxdy. The last thing we do is simply updating the Position field of the axes in which the image is plotted.
Now, to show you some results:
size_factor equals 1.0:
size_factor equals 1.4:
size_factor equals 0.55:
I have this data with values on the edges of the matrix and other values at evenly spaced interval within the matrix. I want to predict the values of the zero positions from the original values and make a heat map of the new data. Through suggest, I use scatteredInterpolant, ndgrid and interpolant since the data is that interp2 (matlab functions) cannot be used to interpolate the zero elements. Now, this method doe not give me a smooth figure and I am want to know if someone can offer some help. I have attached the figure from my code, the data and the code to this post.Thank you.
[knownrows, knowncolumns, knownvalues] = find(DataGrid); %get location and value of all non-zero points
interpolant = scatteredInterpolant(knownrows, knowncolumns, knownvalues,'linear'); %create interpolant from known values
[queryrows, querycolumns] = ndgrid(1:1:size(DataGrid, 1), 1:1:size(DataGrid, 2)); %create grid of query points
interpolatedj = interpolant(queryrows, querycolumns);
HeatMap(interpolatedj)
https://www.mediafire.com/?pq40x1ljxk8h996
https://www.mediafire.com/?pq40x1ljxk8h996
To plot a smoothed matrix you can use pcolor and set the shading parameter to interp
pcolor(M); %where M is your 2D matrix
shading interp %set the shading to interp
Try
image(M) or imagesc(M) where M is a matrix. pcolor(M) also works. If your matrix is huge then you need to remove edges otherwise figure just looks like blank image.
I want to plot a text file with 4 columns that first column in longitude,second in latitude, third is depth and forth is amount of displacement in each point.(it's related to a fualt)
-114.903874 41.207504 1.446784 2.323745
I want a plot to show the amount of displacement in each point (like images that we plot with imagesc),unfortunately "imagesc" command doesn't work for it.
how can I plot it?
Thanks for your attention
A simple way would be to use scatter3 and assign your displacements to be the colours. Note that you have to supply a size for this to work - I'm using [] (empty matrix) which will set it to default. If your four sets of values are four vectors of the same size, then it's just something like:
scatter3(lat,lon,depth,[],displacement, 'filled')
Values in displacement will be linearly mapped to the current colormap. 'filled' gives you filled markers rather than open ones (default marker is a circle but can be changed).
You can plot each point using plot3(longitude,latitude,depth). You can color each point according to the displacement in a for loop. The easiest way to do this is create a colormap, e.g. using jet and chosing the color according to the displacement.
figure;
hold on;
cmap = jet(256);
dispRange = [min(displacement),max(displacement)];
for k=1:size(longitude,2)
c = cmap(1+round(size(cmap,1)*(displacement(k)-dispRange(1))/dispRange(2)),:);
plot3(longitude(k),latitude(k),depth(k),'o', ...
'MarkerEdgeColor',c,'MarkerFaceColor',c);
end
I have 2d line plot in matlab where each line is colored according to a value. I would like to add a colorbar showing the color that corresponds to these values.
I got a solution to plot the lines according to the value I want, however I can not figure out to get the colorbar correctly. I have been searching on this but I am stuck.
Define an RGB color matrix COL.
(N x 3 low red to dark matrix corresponding to equally spaced values 0:1).
Sort the data according to their z value.
Interpolate the COL matrix to get values for all z values, giving the TRUECOL matrix for the lines.
Set the axiscolor-ordering to the TRUECOL matrix and plot the data.
minimalistic example:
% Generate 10 lines of 10 points
x = normrnd(0,1,10,10);
% The corresponding values are
% Note that these do not have to linearly spaced in real code
z = [0,0.05,0.1,0.11,0.12,0.2,0.4,0.45,0.8,0.9];
% Define colormatrix
COL = [0.996078431372549 0.878431372549020 0.823529411764706;...
0.937254901960784 0.231372549019608 0.172549019607843;...
0.403921568627451 0 0.0509803921568627];
% Interpolate the COL matrix to get colors for the data
TRUECOL = interp1(linspace(0,1,3),COL,z,'pchip');
% Set the axis coloring qnd plot the data
set(gcf,'DefaultAxesColorOrder',TRUECOL);
plot(x);
colormap(TRUECOL);
colorbar
I then change the colormap and plot the colobar, however the colors in the colorbar to not correspond to the values z. Is there a way of telling matlab which color corresponds to which value? Looking at the colorbar editor I see that CData must have something to do with it, but I cant find a way to specify that CData should be z.
My understanding is that you want the labels on the colorbar to go from 0 to 1, not 0 to 11. To fix this, use this caxis command. To get finer gradations of colors in the colorbar, you need to more finely interpolate the colormap. Try this:
colormap(interp1(linspace(0,1,size(COL,1)), COL, linspace(0,1,100)));
caxis([0,1]);
colorbar
I'm trying to plot several signals in one graph and i would like to restrict them and sort of minimize it so all my signals will be clear (more or less).
I have no idea how to do it. I'm adding an image so what i need to do will be clearer.
My data changes but in general it's the mean intensity of each column of a certain area in an intensity image.I tried to do it like with the same idea as you but i don't get the right plot as i wanted. A is the relevant matrix,b is the matrix with shifted values:
for i=1:20
b(i,:)=A(i,:)+(100*i);
plot(b(i,:))
hold on
end
I will also add 2 images: one is the plot of all the 20 signals that i get and the other one is the plot of only the first signal. I don't understand why do they look so different.
You can try something like that :
x = [1:100]; %Distance 1 to 100
y = F(x) % Your first function (signal)
y2 = 0.5*G(x) % Your second function (signal)
plot(x,y,x,y2); % plot both function in a single plot.
hleg1 = legend('Intensity t1,'Intensity t27');
So you have your signal at intensity t27 half cut for each value ( 0.5 ), so it shift down.