Community Profile # Joseph Cheng

Last seen: 10 dagar ago Active since 2014

Systems Engineer for Electro-Optical Systems

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Create different outline colors for different times
you can generate a color scale by using the different types of colors like hsv, jet, bone, gray, etc. then depending on the tim...

19 dagar ago | 0

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Change scale of x-axis on plot

19 dagar ago | 0

App Designer: How to plot graph from own function into UIAxess?
if you look at the plot() function or any other display/plotting tools like imagesc(), image(), imshow(), etc... the first entry...

19 dagar ago | 0

I got Error using vertcat Dimensions of arrays being concatenated are not consistent. Error in Code_tubes (line 22) C = [q(1); q(2); q(3);
a quick scan shows it at the last row of C with q(6) - teta2_o - w2*t]; where everything up to that looks to b...

19 dagar ago | 0

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How do I pass coefficients to function handle as an array or list?
i think you just answered yourself in your question y = @(y0,a,b,NN) y0 + a*x(NN) + b*x(NN).^2; %simulate parabolic data yDIF...

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Issue in plotting binary image boundaries with real axis values
so you'll need to find the conversion between pixel to linear xy (mm). sort of the mm/px scale factor + offset to 0; from th...

how can i automatically crop this image? if it is possible.
well, you can find the corner squares by doing the following: img = (imread('https://www.mathworks.com/matlabcentral/answers/up...

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Create variable with name from other variable string
While it is not adviseable to have variables created in this way maybe you have a good reason to but still un-adviseable but her...

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How to find end of time series in plot
to go with your example of pos where pos = [0.11, 0.12, 0.12, 0.12, 0.12 0.12, 0.14, 0.14, 0.11, 0.16, 0.13, 0.13, 0.13, 0.13]...

remove empty rows of a cell
you can use the function cellfun() in conjunction with isempty: clear K %generate dummy K for Cind = 1:2 for Rind = 1:4 ...

Issues in For loop
if we break down your for loop: for i=1:38976; %this if statement will be done if j==120 %an okay statement here b...

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How to find the two minimum values ?
well to remedy this you shouldn't "delete" the entry of the min point but stick in a large value or Nan and use nanmin(). by de...

3d to 2d matrix
take a look at the function squeeze() for ind = 1:3 val(1,1,ind)=-ind; end disp(val) u2 = squeeze(val); disp(u2)

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How to get data points within current camera view?
So... if i'm not mistaken pan in matlab moves the axes limits of the plot and not panning/translating the camera, similarly zoom...

Solved

Find the Pattern 1

Looking for a way faster than find?
without doing some testing to actually test if its faster you can use the found 1's in a to only select a list of indexes A = ...

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Incorrect datatip location on interpolated data
so you can see what is happening if you plot it as just markers in this animated example: figure; hold on; hPlot = plot(1:10, ...

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Taking average of pixel values across multiple frames
couldn't you just put it into a non cell matrix of 5504 x8256 x 3 then use mean(data,3) to take the mean in the 3rd dimension? o...

Why am I getting an invalid file identifier error when using "parfor" but the same function works fine (albeit slow) with "for"?
From the looks of it you've opened a file then trying to use parfor to grab items out of the opened file. However thats where t...

How to get rid of blank space in a heatmap panel of 3 figures?
have you looked at the functions axis equal or axis square those might be applicable to you and not have to only use top h...

How read in comment style to skip the header of a text file?
you can quickly scan the file(s) for the number of header lines like file= 'Graphite_Node_test.txt'; fid = fopen('Graphite_Nod...

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Contour is plotting my data in reflected order?
From a quick test you might not be asigning the x and y values when performing your contour() function. by doing so matlab will...

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Create a matrix with elements clockwise
While probably not the most efficient way you can fill in edges like i've done here: clc;clear all x = zeros(5,8); %generate m...

Update a for loop with if statements
Without running your code i think you can create a sign variable of (-1)^(0 or 1) which switches between 0 or 1 depending on whe...

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Represent array in percentage
you would take your array, subtract the minimum, then divide by the resulting maximum x 100 x = [2.4:.4:4.2]; x = x-min(x); ...

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How to make the length/dimension of 6 different 3D vectors the same?
probably the easiest way is to fill a zero array created to be the same max size then populate the indexes with the values: var...

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Extract pixel values inside a Binary Mask
since you already created a binary mask you can just index multiply " .* " the mask with the original image as outside is 0 and...

how to color and label only certain histogram bars?
Here is an example for @Adam Danz said with using bar y = randn(100); [N X]=hist(y(:),10); %plot all the data figure,clf,hb...

Looking for a matlab script that extracts data from a plot figure ( here 2D contours from Covariance matrix or Markov chains) and reproduce the original figure
your graph is a bit messy with text and lines that denote items. here is a quick example that may push you along. It'll need a...