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Use two bsxfun for row and column vector to span matrix without putting in memory
Hello, I have a vector A of size 1xN and a vector B of size MxN I can span a MxN matrix temp with temp=bsxfun(@times,A,B);. ...

5 years ago | 1 answer | 0

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Question

Efficiently calculate distance between moving point and fixed points
Hello, I have a grid of point coordinates xval=0:1:5000; yval=0:1:2000; zval=1; [X,Y,Z]=meshgrid(xval,yval,zv...

5 years ago | 1 answer | 0

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Question

Better interpolation of nonuniform data to uniform grid than with spline
I am resampling non-uniformly sampled data to a uniform grid with a spline interpolation. However, if the signal is of high fre...

5 years ago | 0 answers | 0

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Question

Speed up 1D spline interpolation on matrix
Hello, I have a NxM matrix named data and I need to spline interpolate each row of my matrix according to: for k=1:size(...

5 years ago | 1 answer | 0

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Question

ned2ecef without toolbox
Are there any user-made functions available somewhere that achieve the same? The lg2ct function in the Geodetic Toolbox on the ...

6 years ago | 0 answers | 0

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Question

Multiply each column in MxN matrix with it's transpose to create MxMxN matrix
Hello, I have a MxN matrix, and I need to multiply each column vector that is of size Mx1 with it's transpose. This gives me...

6 years ago | 2 answers | 0

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Question

Interpolate uniform to non-uniform sampling, artifacts with spline
Hi, I have to resample uniformly sampled data to a non-uniform sampling. I use the spline function for this, and if the sample...

6 years ago | 0 answers | 0

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Question

Merge multiple GPS and IMU to get more accurate position and attitude
I have multiple GPS and IMU that are located at known positions of an aircraft. Is there a ready to use implementation to merge...

6 years ago | 0 answers | 0

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Question

Best way to smooth GPS data
Hi, I have a GPS signal sampled at 1Hz. It is too noisy, so I want to smooth the signal. I tried using a moving average, but i...

6 years ago | 3 answers | 0

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Question

reshape, remove 16 elements, keep 1000*8, remove ..
Can I solve this without a loop?/What is the fastest way? I have a long vector consisting of [16Elements 1000*8Elements 16Eleme...

6 years ago | 1 answer | 0

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Question

Calculate only fraction of spectrum with FFT
I have a signal with 4096 samples. I can calculate the frequency spectrum of this signal with fft. But I am only interested in...

6 years ago | 1 answer | 0

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Question

I need your help! I am going to read a lot of big files with fread. Any ideas on how to speed this up? Also if there is a way ...

6 years ago | 2 answers | 0

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Question

Matrix indexing: fast way to compute covariance of N different MxL matrices that are saved in NxMxL matrix
I have a NxMxL matrix called bigmatrix That I can split into N temporary submatrices. On each temporary submatrix I need to ca...

6 years ago | 1 answer | 0

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Question

IFFT calculate only one timesample
I have a frequency signal and I apply an IFFT to it. This results in the time domain x(n) which has N samples. But I am really...

6 years ago | 1 answer | 0

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Question

Combine multiplication filter in time and frequency domain
Hello, I perform a FFT on my signal x, which yields X. Then I perform a multiplication in the frequency with my filter W, whic...

6 years ago | 1 answer | 0

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Question

bsxfun to multiply matrix with vector multiple times in for loop --> how faster?
I have a 2D matrix of size NxN, and each row I am multiplying with a 1xN vector with bsxfun in a for loop like this: for k=...

6 years ago | 2 answers | 0

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Question

How to vectorize loop with linspace for performance
Besides prelocation my matrix A, how can I save time here? for k=1:1:10000 A(k,:)=firstValue(k):fixedStep:lastValue(k); ...

7 years ago | 1 answer | 0

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Question

Fast Look-up table
Good morning, I have a long array signal with values x. Now for each of those values x I want to find the closest fit in anoth...

8 years ago | 1 answer | 0

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Question

Highly interpolate complex spectrum
Good afternoon, I have a complex spectrum of a signal that is centered around a center frequency with a certain bandwidth. I...

8 years ago | 0 answers | 0

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Question

Highly oversample FFT2 in one direction for peak detection
Hello, I have a 2D image and the resulting FFT2 has high peak. Now I can find the maximum to get the resulting peak shift in e...

8 years ago | 0 answers | 0

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Question

Translate position uncertainty of two objects to uncertainty of distance between them
Hello, I have a plane and in this plane there are two objects. The real location of each object is somewhere in the circle o...

8 years ago | 0 answers | 0

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Question

Probability of two adjacent cells being below gaussian percentile
Hello, I have a matrix, whose data is described by a gaussian curve. Now I have a probability of 8%, that the data falls below...

9 years ago | 1 answer | 0

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Question

Precision when dividing two functions going against zero
Hi, I have two functions A=sinc(c1*x)-cos(c2*x) whichs is Zero for x=0. Now I want to calculate A/(c3*x). The expected result...

9 years ago | 2 answers | 0

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Question

Hello, with imgradient I can compute the magnitude and direction of an image's gradient. Is it also possible to somehow comput...

9 years ago | 1 answer | 0

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Question

Height difference between earth models
Hello, is it possible to calculate the height difference between earth models at specific points of lat and long? For example ...

9 years ago | 0 answers | 0