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# Ridwan Alam

##### Last seen: Today
120 total contributions since 2019

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Errors using function and fsolve
% *Set universal constants:* global surr sink sigma sigma = 5.67e-8; % Stefan-Boltzmann constant (in W/m^2/K^4) % % *S...

1 jour ago | 0

Linear regression outputs (regstat function)
The first one is for the constant coefficient (aka intercept term). I believe you have only one predictor x, then your model is...

1 jour ago | 0

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T-wave on ECG
If I understood right what you are asking, you need to find the peaks for P,Q,R,S, and T using findpeaks(). https://www.mathwo...

15 jours ago | 0

making dataset 3D data function
Let's assume your variables are named as 'input01', 'input02', ... 'input48'. my3Ddata = []; myMeanData = []; varnames = wh...

15 jours ago | 0

How can I save a image from imshow into a cell array ?
I don't think you need the imshow(). imshow() is only used to show the image, and it returns an image object, which is not norma...

18 jours ago | 0

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Piecewise function of y
It's a bit hard to understand the issue here. Please let me know if this is not what you are looking for: plot(C2(20:90), heigh...

18 jours ago | 0

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Replacing NaN with blanks in a matrix
I believe you are looking for fillmissing() or rmmissing(): https://www.mathworks.com/help/matlab/ref/fillmissing.html https:/...

18 jours ago | 0

linear regression of time series with time index
If you have a fixed equation like the one provided, I believe you are looking for parameter estimation methods to find beta_0, b...

18 jours ago | 0

K = round(Tuq'*eye(5)*Tuq,2); M = [ m 0 0 ; 0 m 0 ; 0 0 I ]; eq = det(K*k-w1*M); s = solve(eq,w1); will prevent sym() to con...

20 jours ago | 0

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FFT filter on voice file help please
There are multiple ways you can filter these data. You can use bandpass, high or low pass filters, or any other specific filters...

environ un mois ago | 0

Change the Samples per frame property on the Sine Wave block: https://www.mathworks.com/help/dsp/ug/transform-time-domain-d...

environ un mois ago | 0

Digital signal processing LINEAR AND CIRCULAR CONVOLUTION length-N sequences error
x = [2+3j 3-1j -1+2j 3j 2+4j]; https://www.mathworks.com/help/matlab/ref/j.html

environ un mois ago | 0

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How to detect variations in data?
Depends on how complex of a solution you are looking for. There are algorithms for change point detection that you can try. htt...

environ un mois ago | 1

Which Right Eigenvector to report?
I assume you meant 'right' as opposed to 'left' eigen vectors. [V,D] = eig(A); % to get left eigenvectors, [V,D,W] = eig(A), he...

environ un mois ago | 0

Creating a table for the "For-loop command" results:
Even though there are many more efficient ways to do this, this is a simple addition to your code: clear clc n=input('Enter t...

environ un mois ago | 0

How to extract sub-matrices from a big matrix?
% to find the matched date and store the that day along with the following 5 days (120 hours) in another matrix. for n = 1:siz...

environ un mois ago | 1

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How to change nonzero values to 1 within a table?
tempTable = table2array(myTable); tempTable(tempTable~=0)=1; myTable = array2table(tempTable);

environ un mois ago | 0

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Replace NaN's in a table - I need some help

environ un mois ago | 1

Adding values of Columns in a matrix to create another matrix (for loop)
dim=size(E_min,2); % dim = 25 fun = @(E) A*exp(-E/kT); Np = []; nyi = []; for i = 1:dim Np(i)=integral...

environ un mois ago | 1

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How to mark a specific point on CDF graph?
Assuming you have 4 cdf arrays, you can find the x-values as: cdf1ind = find(cdf1>=.80,1,'first'); x1 = x(cdf1ind); cdf2ind = ...

environ un mois ago | 0

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How to write a code to estimate parity of numbers in a sequence?
bnumbers = [5 0 8 3 9 2 7 6 1 4 8 1 0 5 9 7 2 6 3 4]'; bresponse = [0 0 1 0 0 0 0 0 0 2 0 2 2 0 0 0 0 0 0 0]'; bbinary = ...

environ un mois ago | 0

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Signal Decomposition for a mixed signal
t=0:0.00001:0.3; x1=(exp(-3*t)).*(0.2*sin(2*pi*400*t)); x2=1.2+(exp(-1.5*t)).*(1.1*sin(2*pi*40*t+pi/6)); x3=(exp(-5*t)).*(0.8...

environ un mois ago | 0

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Hi I am having a hard time using the getfield. It says there is an error.
lat = getfield(latStruct,latField{1});

environ un mois ago | 0

Index exceeds matrix dimensions
I tried this, it worked fine. No error: date_start = "2015-01-01"; date_end = "2019-10-01"; char_date_start= char(date_start)...

environ un mois ago | 0

Force nodes to my graph
plot(digraph(o,d,[],24))

environ un mois ago | 0

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how can I creat a matrix of all possible combinations of zero and ones across eight digits.
decimalVector= [0:1:(2^8)-1]'; binaryMatrix = de2bi(decimalVector);

environ un mois ago | 1

Exporting model to classify new data
1.Save: (assuming you want to save/export each classifier in separate files) use save(). 2. ROC curve: use perfcurve() and plot...

environ un mois ago | 1

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IFFT of Convolution equivalence
Sorry for the confusion. Here is what I tried: a1 = randi(50,8,1); b1 = randi(50,8,1); x = complex(a1,b1) a2 = randi(50,8,1)...

environ un mois ago | 1

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Turning a matrix into a vector issue where it truncates (easy question)
finalMessage = reshape(messageSymbolsDemod,[],1); % from matrix to vector finalMessage = padarray(finalMessage,16-length(finalM...

environ un mois ago | 0

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sub2ind gives error: Error using sub2ind (line 43) Out of range subscript.
In your code, xs contains negative values, which can't be the column indices. Also, sc is only 1004x1144. But the values of xs ...

environ un mois ago | 0

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