Refer to the attached image. I want to display the image in Matlab using the function `surf()`

. However, I only want to display the region of the actual object without the background (the pale-green region surrounding the actual object which has 0 value). How to do that? I tried replacing all the outer region with `0`

with `NaN`

and setting all the values in the height map to a nonzero value, but still I get an error message:

```
Subscript indices must either be real positive integers or logicals.
```

So how can I display a surface that has a non-rectangular boundary?

Answer:

Setting those values to `NaN`

should do. Here's an example:

```
[x, y] = ndgrid(linspace(-1,1,500));
z = cos(2*pi*(x+y)*2);
z(x.^2+y.^2>1) = NaN; %// remove values outside unit circle
surf(x,y,z,'edgecolor','none')
colorbar
view(2)
axis equal
```

matlab,machine-learning

This is my implementation of CostFunctionJ: function J = CostFunctionJ(X,y,theta) m = size(X,1); predictions = X*theta; sqrErrors =(predictions - y).^2; J = 1/(2*m)* sum(sqrErrors); But when I try to enter the command in MATLAB as: >> X = [1 1; 1 2; 1 3]; >> y = [1; 2; 3];...

matlab,plot,signals,circle

I have some random signal (for example sin signal) with the time scale. t=0:0.1:2*pi y=sin(t) plot(t,y) Now I want to draw this signal on this circle. So the time vector actually becomes an envelope of the circle. Envelope of the circle represents "y = 0" in cartesian coordinate system. Here...

matlab,image-processing

I have a labeled matrix containing two objects. How can I thicken an object to a curve? Actually I have the following image: and I want this: Each pixel of the resulting curve is the median of each column. But if you have another idea, it is acceptable, because I...

matlab,filtering,convolution

I'm trying to design a Wiener filter in Matlab for a deconvolution problem but I'm having a lot of problems. I have a gaussian white noise process with a variance of 1.2 and a impulse response which has length two. Its values are g(0) = 5 and g(1) = 4....

python,opencv,image-processing,python-imaging-library

I'm trying to downsample my image(using anti-aliasing) using Python-Pillow's im.thumbnail() method. My code looks like: MAXSIZE = 1024 im.thumbnail(MAXSIZE, Image.ANTIALIAS) Can you tell me some alternative in opencv-python to perform this re-sizing operation ?...

matlab,plot

I want to display three figures in a figure window. Assuming that I divide 2x2 regions. subplot(2,2,1) ---------+----------- | R1 | R2 | ---------+----------- | R3 | R4 | ---------+----------- I want to show a figure merging R1 and R3 ant other two in R2 and R4 I can display...

matlab,regression

I am doing some bone segmentation whereas the result of this segmentation is points placed in a circular pattern around this bone. However as it is taken using a qCT scan, there is quite a lot noise (from e.g. flesh) on the points that i have. So the overall problem...

matlab

What is the ellipsis for in this Matlab statement? frame = insertObjectAnnotation(frame, 'rectangle', ... bboxes, labels); ...I could not find in their online doc....

image,matlab,image-processing,mask,boundary

I'm trying to create a mask (or similar result) in order to erase pieces of a binary image that are not attached to the object surrounded by the boundary. I saw this thread (http://www.mathworks.com/matlabcentral/answers/120579-converting-boundary-to-mask) to do this from bwboundaries, but I'm having trouble making suitable changes to it. My goal...

arrays,matlab,matrix

I have matrix A and matrix B. Matrix A is 100*3. Matrix B is 10*3. I need to insert one row from matrix B each time in a sequence into matrix A after every 10th row. The result would be Matrix A with 110*3. How can I do this in...

matlab,polynomial-math

I have the following code: syms z Gc=1.582*(1-0.3679*z^-1)/(1+.418*z^-1); Ghp=.3679*(z^-1)*(1+.718*z^-1)/((1-z^-1)*(1-.3679*z^-1)); T=(Gc*Ghp)/(1+Gc*Ghp); clipboard('copy', latex(simplifyFraction(T))); Which results in following for T: How can I normalise coefficients? I.e. I want the z2 in denominator and z in numerator to have the coefficient of 1. Is there any function in Matlab to do so?...

php,image-processing,imagemagick

Overview: The first picture is my original image. Here I want to replace the white rectangle shown with another image. My approach: I have created a mask image using floodfill and it looks as: Problem: Now I would like to get the distance or co-ordinates of the rectangle in the...

python,image-processing,imagej

I wrote a multilanguage 3-D image denoising ImageJ plugin that does some operations on an image and returns the denoised image as a 1-D array. The 1-D array contains NaN values (around the edges). The 1-D array is converted back into an image stack and displayed. It is simply black....

string,matlab,filenames

I am using the below mentioned code to get the file names of images according to their id's from images_1 text file as strings and use them to read the images from their directory image_count=1; for image_count=1:6 file=fopen('D:\Academics\New folder\CUB_200_2011\images_1.txt','r'); C = textscan(file, '%s'); original_image=imread('D:\Academics\New folder\CUB_200_2011\images\%s','C{1}{2*(image_count)}'); imshow(original_image) end I am able...

matlab

A text file could be loaded as below: load sourceETA/Record1/result1.txt How can I use a variable in address of loading? For example (n is a variable): [load 'sourceETA/Record1/result',num2str(n),'.txt'] But the above code doesn't work! How do I do?...

matlab,image-processing

I have a binary matrix containing several binary objects and I want to bridge between them. Actually I have the following picture: And the result has to be like this: Is there any function or a shortcut way, other than loops, for this problem?...

string,matlab

I have a string "FDFACCFFFBDCGGHBBCFGE" . Could anyone help me to generate a new string with the same order but no element inside repeated twice. Thanks ! The expected output should be like this : "FDACBGHE"...

matlab

Is it possible to add statements in between the codes. For example: If I have a code like this, r(:,1) = a(:,1) - a(:,2); Then can I write it as, r(:,1) = a(:,1)("this is a constant") - a(:,2)("this is a variable"); ...

matlab,matrix,multidimensional-array,scalar

I'm having problems multiplying specific values within my multidimensional matrix by a scalar. My matrix has the following dimension: size(comDatabe) = 5 10 3 397 10 The third dimension is an x-y-z coordinate frame. Something went wrong and now my y-axis is defined upside down for one subject (#8 out...

matlab,system,equation

sorry if it already has a answer..i tried other links but it didn't understand i have 2 1*63 array .landa and v. each of their members are syms. and each v member is a function of all landa members.i have already calculated v members and they are all symbolic equations...

matlab,time-frequency

Code tfr = abs ( tfr ); [row_size, column_size] = size(tfr); tfr = tfr(1:round(row_size/2), 1:row_size); surf(tfr); view(2); I get in R2014b of OSX 10.10.3 Yosemite but rotating around shows that the cells should not be black Why is the output black? I wonder if this is a hardware problem or...

image,matlab,image-processing,image-segmentation

I have an image which I want to divide into overlapping blocks. I have set the box to be of size 8 rows and 8 columns, and the overlapping factor to be 4 rows/columns. This is what I have written to solve this: img = imread('a03-017-05.png'); overlap = 4 count...

matlab,plot,legend,movie

i have a question regarding legend for movies. This is my code: fig = figure(); for i = 1: 70000 plot(signal1) hold on; plot([i,i],[-5,5]) plot(signal2,'r') hold off; title('\fontsize{14} my data'); legend('signal1','signal2'); axis tight; f(i) = getframe(fig); end The legend shows the same colors for the first two things I plot....

matlab

my matlab version is 2012a. when I use fitcknn,has this error: Undefined function 'fitcknn' for input arguments of type 'cell'. how to calculate probability for each class for predicate with knn without fitcknn? after use this code, I want to calculate prob_estimates for each neighbors: knn = ClassificationKNN.fit(trainsample, trainlabel,'NumNeighbors',7); y...

matlab,matrix,least-squares

How can I solve , where and and in the least squares sense in matlab? So I'd like to have the minimizing as output....

matlab,svm,auc

I'm having a weird problem in training an SVM with an RBF kernel in Matlab. The issue is that, when doing a grid search, using 10-fold cross-validation, for the C and Sigma values I always get AUC values equal to approximately .50 (varying between .48 and .54 depending) -- I...

matlab,matlab-figure

I'm struggling to plot multiple functions on one figure. Here is the code that I have: syms t a; a=0.9514; F1=0.5*sqrt(3*t^2); F2=-0.28375*t^2+1.155*a*(t-a)+1; F3=1; E1=diff(F1,t); E2=diff(F2,t); E3=diff(F3,t); I want to plot E1, E2 and E3, each only within a certain range, to make a "composite" line. I've tried plotting with ezplot...

arrays,matlab

I have two vectors, one of them stores the width dimension of a set of images and another one the height of these set of images. I want to use these values as two dimensional vectors [width height] and store them in a matrix. The first line, for instance, keeps...

c,matlab,fopen,mex

I have a little experience with Matlab, but am new to the mex environment. What I am trying to do is to save some values I compute to a txt file in my C routine. For the sake of simplicity I am using the example arrayProduct.c from MathWork's Create C...

c++,matlab

Is there an alternative way to call a C++ class using MATLAB, and operate its methods on MATLAB variables?

excel,matlab,cluster-analysis,k-means,geo

I have 8 traveling consultants that need to visit 155 groups across the continental united states. Is there a way to find the optimal 8 regions based of drive time using k-means clustering? I see there are some methods implemented already for other data sets, but they are not based...

matlab,events,delay

In Matlab functions can be started at events,but occasionally, like with the resize function, the events are called in rapid order and the function is called many times in succession, which can cause weird behavior and lag. Is there a way to have it listen for the event but only...

matlab,loops,for-loop,while-loop,do-while

This is my one dimensional array A. containing 10 numbers A = [-8.92100000000000 10.6100000000000 1.33300000000000 ... -2.57400000000000 -4.52700000000000 9.63300000000000 ... 4.26200000000000 16.9580000000000 8.16900000000000 4.75100000000000]; I want the loop to go through like this; (calculating mean interval wise) - Interval length of 2,4,8 (a(1)+a(2))/2 - value stored in one block of...

matlab,matrix

I have a matrix looks like: 0 0 0 0 0 1 0 0 0 0 0 2 0 0 0 0 0 2 0 0 0 0 0 1 0 1 0 0 0 1 0 4 0 0 0 0 0 3 0 0 6 0 0 4...

image,matlab,image-processing,computer-vision

I need to save a set of pre-processing images in matlab, resulting in grayscale images. The problem is the fact that these pre-processed images have pixel values higher than 255. If I save them with imwrite() as, for instance, .PNG files, does matlab normalize the values to be in [0,255]...

matlab,plot

I have multiple 2D line plots in Matlab (they represent some wave moving through space). Each plot represents the wave at some time t. I want to animate through these plots (i.e. show the first plot for a fraction of a second, then show the next one, and the next,...

matlab,distribution,sampling,random-sample

How can I create a vector x in Matlab that has values between 0.8 and 1.2, randomly sampled from a: 1. Uniform 2. Normal distribution? There are a lot of functions dealing with distributions, but I'm having trouble using them properly....

matlab,typeconverter

I'm currently using a MATLAB to work and I need some help: I need to convert my output data (variable: units) be a double instead of a cell because I must perform a sum: units = inputdlg(question,title); sum = units + i; I've tried this code also but didn't solve...

matlab

I have 20 column vectors in the workspace and I'd like them all to be contained within a cell array. They're all labelled data1, data2, data3,...data20. Is there a faster way to do this than: cell = {data1, data2, data3, data4, data5, data6, ...} all the way up to data20?...

matlab,cell

I'm trying to equate each element to an array which correspond to cell element. To explain it more precisely, e.g A = {[1 1 1], [0 0 0 0 0], [1 1],[0 0 0 0 0]}; B = [0 1 0 0]; So the thing I want is : A=...

matlab,plot

I have a semilogarithmic plot which works so far with semilogx. Now I would like to change the tick labels. Now it says 10^8 10^9 ... 10^13, but I would like to see 1e8, 1e9, ... 1e13 on the x-axis. How can I change that? Cheers Manuel...

matlab,image-processing

I am trying to read all the images in the folder in MATLAB using this code flst=dir(str_Expfold); But it shows me output like this. which is not the sequence as i want. Can anyone please tell me how can i read all of them in sequence? for giving downmark, please...

matlab

So, I want to be able to look at (read: copy) MATLAB's NonLinearModel method of printing the regression results to the screen such as this. Nonlinear regression model: y ~ (alpha1 - alpha2*t^0.5) Estimated Coefficients: Estimate SE tStat pValue alpha1 1.0253 0.0082253 124.66 4.8823e-24 alpha2 0.0061783 0.00073277 8.4314 4.4834e-07 Number...

matlab,simulink

I am working on a simple System Object in Matlab/Simulink. It looks like this : classdef realtime_header_detectorSO < matlab.System & matlab.system.mixin.Propagates % correlateHeader % % This template includes the minimum set of functions required % to define a System object with discrete state. properties Header %nrOfBitsInPreviousStep=0; s=100; d=zeros(1,s); end properties...