Answered
2nd 3rd derivatives
x = [-2:0.01:1]; y = exp(-3.*x); dy=gradient(y,0.01); ddy=gradient(dy,0.01); plot (x(3:end),ddy(3:end))

4 years ago | 0

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Answered
How to fill just such successive elements in row of matrix?
Is this what you want? A=[9, 50, 18 3; 11 7 50 10; 1 2 3 50; 50 3 4 5] B=cumsum(A==50,2)*50 C=B+~B.*A

4 years ago | 0

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imfreehand() closes the curve in the image but does not save those "closing" points
Use thte points to contruct a polyshape object, plot(polyshape(points))

4 years ago | 1

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imfreehand() closes the curve in the image but does not save those "closing" points
Copy the first point and append it to the end of the list

4 years ago | 0

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Answered
To write a For loop in which a variable is updated with each run.
Why not just do, pgon=nsidedpoly(18); pgon.Vertices plot(pgon); axis equal

4 years ago | 2

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cant seem to make the background fully black
A=imread('https://www.mathworks.com/matlabcentral/answers/uploaded_files/1141370/original.png'); B=imclose(edge(A),strel('dis...

4 years ago | 1

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cant seem to make the background fully black
A=imread('https://www.mathworks.com/matlabcentral/answers/uploaded_files/1141370/original.png'); B=imquantize(A,multithresh(A...

4 years ago | 1

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Answered
How to determine if a 3D line segment intersects a side of a 3D rectangular prism?
You can also use Siddon's algorithm https://aapm.onlinelibrary.wiley.com/doi/epdf/10.1118/1.595739 which will compute the int...

4 years ago | 0

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how to remove the tiny white pixels around the rectangles
imopen(yourImage,ones(3))

4 years ago | 0

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how to define a matrix element in matlab
B(1:2,1:2)=A

4 years ago | 0

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Answered
create a random matrix that satisfies specific criteria (graph theory)
Just permute the rows and columns of the original adjacency matrix, A, [~,is]=sort(rand(264),2); for k=1:264 A(k,:)=A(k,is...

4 years ago | 0

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How to determine if a 3D line segment intersects a side of a 3D rectangular prism?
You can use intersectionHull() in this FEX download, https://www.mathworks.com/matlabcentral/fileexchange/30892-analyze-n-dimen...

4 years ago | 2

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Answered
Can you please help me to get the square root of the sum of squares of the second column in the text file ?
Your attachment didn't make it, but assuming it's called yourFile.txt, [~,col]=readvars('yourFile.txt'); result = norm(col(~...

4 years ago | 0

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Answered
Matrix multiplication along a specified dimension?
B=pagemtimes(A,X)

4 years ago | 0

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Answered
Why do I get an error using "-" along with the message "too many output arguments" when using fmincon?
You have not shown us fValue2, but more than likely, it does not specify any output arguments to be returned.

4 years ago | 0

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Extract the bigger number of values from the previous one in an array
Easier to do, Data = rand(1,15) X=10*(diff(Data)>0)

4 years ago | 0

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Answered
Fit ellipse in 3D space
Another possibility is to use this FEX download, https://www.mathworks.com/matlabcentral/fileexchange/87584-object-oriented-to...

4 years ago | 1

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Answered
Help using fmincon to find the 2 support locations (x1,x2) that minimize maximum bending moment
I need to minimize the maximum bending moment from 0 to L Do you mean the maximum from among [b1 b2 b3]? If so, you probably wa...

4 years ago | 0

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Find the key for vector transformation
See Example 2: Optimal Reordering of Points in the Examples tab of https://www.mathworks.com/matlabcentral/fileexchange/52795-c...

4 years ago | 0

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How to create a column vector repeating the same character n times?
and has the same character repeating in each row like 'on'. 'on' contains two characters. Repeating it for N rows would give a...

4 years ago | 1

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Answered
Removal of the the edges from the node of a graph
You want to remove the edges but keep the node itself? If so, G=rmedge(G,outedges(G,nodeID)) If you want to remove the node an...

4 years ago | 0

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Answered
How to obtain and plot perpedicular lines using the gradient of a function
Your plot is correct. The lines just don't look perpendicular because of the plot aspect ratio. x = linspace(-2,1,100)'; y ...

4 years ago | 0

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Fit ellipse in 3D space
I am searching for intersection of plane and ellipsoid If that is the ultimate goal, you should just rewrite the ellipsoid equa...

4 years ago | 0

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How can I transparent my gaussian distribution and convert to a transparent ellipse
You can extract the points on the contour lines using tis FEX download https://www.mathworks.com/matlabcentral/fileexchange/740...

4 years ago | 1

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Answered
How can I remove object in binary image by using a mask
You can use bwlmaskpropfiltn() from this FEX download, https://www.mathworks.com/matlabcentral/fileexchange/90762-further-tools...

4 years ago | 1

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Answered
How can I include the legends within the for loop and how can I set the xticks in MATLAB?
So, how can I include legends with the for loop instead of writing it outside? You are assuming here that the for loop is the o...

4 years ago | 0

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Answered
Rect function with Array
function [y] = rect(T0, A, t) y= ((t >= -T0/2) & (t <= T0/2)) * A; end

4 years ago | 0

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Answered
Count the occurrence of each element in an array
string = 'I am happy'; [N,e]=histcounts(double(string),32:130); table(char(e(N>0)'),N(N>0)','VariableNames',{'Character','...

4 years ago | 0

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Answered
Why the outcome of my code is just white image?
Give imshow() a second argument to see the desired grayscale range. img1=im2gray(imread('cameraman.tif')); kernel = ones(3, ...

4 years ago | 1

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Answered
if and sum not working together
Because the sum cannot be done exactly in floating point. Therefore you need a tolerance, a = zeros(10,1)+0.001; b = sum(a) i...

4 years ago | 1

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