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David Goodmanson


David Goodmanson

578 total contributions since 2012

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Answered
Interpreting xcorr results compared to corrcoef
Hi Jonathan, For the input column vectors, corrcoeff subtracts the mean off of each one and normalizes each to be a unit vector...

약 19시간 ago | 1

Answered
How to generate matrices that satisfies constraints on sum of row elements and sum of column elements?
Hi sharadhi, Here is an example for 3x3, where all the row and column sums are 100 (looks like you edited the original question...

약 23시간 ago | 0

Answered
How can I find a p-value when dealing with a weighted sum of chi-square distributions?
HI Michael, I believe this is just the weighted sum of the individual p values for each chi-square at the given value of x, su...

1일 ago | 0

Answered
Cumulative distribution function of a function of a random variable
Hi Franziska, a = 1.2; x = .2 y = a*(1+x)*(2/(1+ (1+x)^(1/(a-1))))^(a-1) xx = (y/a)/(2-(y/a)^(1/(a-1)))^(a-1) -1 % ...

3일 ago | 0

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Answered
FFT interpolation using zero-padding and the Chirp Z-Transform for a single tone sinusoid
Hi Matt, I made one minor change at the beginning of your code, replacing the first four lines with M = 100; m = linspace(0,1...

5일 ago | 0

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Answered
Fourier transform of table signal
Hello fima, It’s true that the amplitude is off, but frequency is a much more serious issue. The time domain plot shows that t...

5일 ago | 0

Answered
fourier transform of exp
HI Hadimargo, A few modifications are necessary to make this work out. oo First, in the time domain the exponential function i...

9일 ago | 1

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Answered
Generate random numbers from a mixture distribution
Hi Thomas. I presume you mean something like the following. A uniform random variable is used to create an index that picks fr...

14일 ago | 2

Answered
How to rotate the plot attached(Truncated Pyramid) to make its sides parallel to its Axis.
Hi adam, two lines become y(m)=R*sind(n+45); x(m)=R*cosd(n+45);

21일 ago | 0

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Answered
Trouble with MATLAB Triple Integral
Hi Goerge, The problem with the func([x,y,z]) approach is that there is too much expectation that [x,y,x] is 1x3. Once the int...

23일 ago | 0

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Answered
Linear interpolation with multiple values for each point
Hi Justin, If the problem is what I think it is, with d and e known, linear interpolation between o and p determined by a<d<b ...

23일 ago | 0

Answered
Problem with the Color Bar
Hi Hans, try colormap(jet) colorbar by default this has 64 color levels (as does the default colormap, 'parula') and looks m...

25일 ago | 1

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Answered
Question about fft2(2D Fourier Transform) of a Gaussian function
Hi Zhu Li, A couple of things are going on here. First, there is the checkerboard pattern in the angle plot. I added an extra ...

28일 ago | 1

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Answered
The power sum of all frequencies seems that the half amount of the middle frequency power is not added. But the algorithm accords with the Parseval theorem. why?
Hi H^2, It helps that you are doing this for four frequencies rather than some crazy huge number of them. x = 1:4; N = length...

약 1달 ago | 0

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Answered
Problem with symbolic Fourier Transform
Hello Halil, For the delta function, delta(x-x0) = |a| delta(a(x-x0)) so with a = 2*pi, both versions are correct. quick lo...

약 1달 ago | 1

Answered
How does function std process complex numbers
Hi JFz, First of all, for a matrix the std is calculated independently for each column, as is true of many Matlab functions. F...

약 1달 ago | 1

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Answered
Simple squaring of expression
HI Wesley, syms a syms b syms c syms d syms e f = expand((1*a+2*b+3*c+4*d+5*e-8)*(1*a+2*b+3*c+4*d+5*e-8))

약 1달 ago | 0

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Answered
How to solve this equation which contains complex number, bessel equation and its derivative?
Hi bohan shen, The first six roots are shown below. First, since J1 is odd and J0,J2 are even, if z is a root then so is -z. ...

약 1달 ago | 1

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Answered
How do I assign matrix of strings to matrix of numbers?
Hi [A,B,C,D,E,F] = deal(5,8,2,9,2,1) although for a large number of variables, giving each its own name is not a winning strate...

약 1달 ago | 0

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Answered
Finding and plotting radial component in vector field
Hi djr, nc = 14; nr = 14; % Create grid [x,y] = meshgrid(0:dx:(nc-1)*dx,0:dy:(nr-1)*dy); % Plot vectors (rows and colomns ne...

약 1달 ago | 0

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Answered
How to solve first-order nonlinear differential equation where the solution is coupled with an integral?
Hi Califfo; This may be in line with what you want. At least it's changing size It's based on the idea that you know not onl...

약 1달 ago | 2

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Answered
Errors when solving equation numerically with a Heaviside Theta
Hi A7, The code below finds a solution. Instead of looking for phi0 directly it uses the variable beta = 1/(lambda*phi0) Sin...

약 2달 ago | 0

Answered
Randomly select an element from a vector satisfying a condition
Relative speeds are going to depend on the length of X and the value N that the elements have to be greater than, (2 in the exam...

약 2달 ago | 0

Answered
Matrix grouping result of combinations
Hello Joao, Maybe I need to write better blurbs. Here is a general solution for even n, with a verification check that shows t...

약 2달 ago | 0

Answered
Mesh doesn't work for cone shape?
Hello TY, I don't know if you need a fancier triangular mesh, but here is a way to a 'square' one. r = 0:.05:1; th = linspace...

약 2달 ago | 0

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Answered
Standard deviation of decimal numbers
Hi Jill, This is just the usual numerical 'error' due to the limitations of floating point arithmetic. std(.1*(ones(1,1e5)))...

약 2달 ago | 1

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Answered
Create block sparse matrix
HI ks, Here is one way. MODIFIED (see comment thread below) showing two possible methods to fill the matrix by means of a ...

약 2달 ago | 1

Answered
Flatten Matrix in Row Major Order in Arbitrary Dimensions
Hello Lucas-Raphael, I'm not sure this is what you are looking for, but B = permute(A,[6 5 4 3 2 1]); % (however many dim...

2달 ago | 0

Answered
Looking for a function f(x,y,z) based on 3 points to calculate interpolated/extrapolated values with a linear relation
HI Appli, This is something Matlab does really well. I assume by 'linear relation' you mean that each point has a value c = a...

2달 ago | 1

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Answered
Cannot plot Fourier Transform
Hi Reza, If you take a look at X, the result is X = -((pi*w*sign(w))/2 + fourier(cos(4*t)/t^2, t, w)/2)/pi^2 which shows tha...

2달 ago | 0

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