Answered
How to get p-val from correlation coefficient and number of sample?
??? I told you that the the t above is t-distributed with n-2 degrees of freedoms. Once you know the distribution, the p-value i...

14 years ago | 0

Answered
command 'downsample' in matlab doesn't work
Please enter: >>which downsample at the command line. I think in your R2010b version you have some other downsample.m (...

14 years ago | 3

Answered
How to get p-val from correlation coefficient and number of sample?
The p-value is based on a t statistic t = r* sqrt((n-2)/(1-r^2)) which has n-2 degrees of freedom. You can find a discussion...

14 years ago | 0

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Answered
command 'downsample' in matlab doesn't work
I think you need to give the error message, if any, you receive in R2010b. Do you have the Signal Processing Toolbox in your R20...

14 years ago | 0

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Answered
Does the fft automatically use a dft algorithm?
Hi Peter, MATLAB has multiple FFT algorithms. The transform is the discrete Fourier transform (DFT). FFT algorithms are just imp...

14 years ago | 0

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Answered
how to generate random points in a matrix
If you have the Statistics Toolbox, you can use randsample() I'll assume a 256x256 matrix for this example. indices = rand...

14 years ago | 0

Answered
signal denoising using wavelet transform
Hi, see the help for wden()

14 years ago | 0

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Answered
Nyquist rate is not true always
@iVenky, @Daniel "I need to know only phase. I don't need the amplitude. I assumed that the initial phase is zero. Then I can fi...

14 years ago | 1

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discrete fourier transform
Hi, because the filter has been designed as a lowpass filter. When you filter a signal, you multiply its Fourier transform by th...

14 years ago | 0

Answered
Nyquist rate is not true always
OK, here is a 30-point signal 0.9239 0.5225 -0.0785 -0.6494 -0.9724 -0.9239 -0.5225 0.0785 ...

14 years ago | 0

Answered
Nyquist rate is not true always
Venky, with all due respect, you're missing the point. How are you going to tell that it was 5 kHz and tell its correct phase? T...

14 years ago | 0

Answered
Use of FFT instead of Bank of Bandpass filters for DTMF Tone detection in Matlab
Hi Moonman, I answered this question Enter >>dtmfdemo and the look at the code. That is using the DFT. It does not use band...

14 years ago | 0

Answered
Nyquist rate is not true always
but how do you know it's 5 kHz and not 3 kHz with a different phase? or 13 kHz, or 24 kHz, and so on, that is the point of alias...

14 years ago | 0

Answered
Nyquist rate is not true always
Hi Venky, That is not correct. There are a few flaws in your reasoning: How do you presume to tell that the frequency is actu...

14 years ago | 0

Answered
How find the integral of a function from 0 to a equal to a certain number
Hi, Do you want to do this integration symbolically, or numerically? See the help for quad (numerical) and sym/int >>doc...

14 years ago | 0

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Answered
Basic filtering related question
Hi Etienne, I don't think your filter is doing exactly what you think. I'm a bit confused by D = filter() since your graph has L...

14 years ago | 0

Answered
How to obtain the t-value of the Students' t-Distribution with given alpha, df and tail(s)
alphaup = 1-0.01/2; alphalow = 0.01/2; upp = tinv(alphaup,1); low = tinv(alphalow,1); Requires Statistics Toolbox

14 years ago | 2

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Answered
problem with if statement
if (0<ang && ang <1.5708) quad=1; elseif (1.5708<ang && ang<3.1416) quad=2; elseif (-1.5708<an...

14 years ago | 0

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Answered
Temperature data
Is it "varied more than 2" in absolute value? or just greater than? Let X be the data matrix. Y = abs(diff(X')); X(Y>2) = N...

14 years ago | 0

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What filter command is actually doing
I think detection by using the DFT is the way to go. I understand the exercise you were working on, but I think most real-world ...

14 years ago | 0

Answered
What filter command is actually doing
Hi, yes filter() is convolution. filter() actually uses what is called a direct-form II transposed structure to implement the...

14 years ago | 0

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Answered
input=f(x) or f(x,y) how to plot/surf such unknown funktions?
If you like Andrei's suggestion z = eval(['@(x,y)',input('f(x,y) = ','s')]) Then user enters: cosd(x)-sind(y) ez...

14 years ago | 0

Answered
input=f(x) or f(x,y) how to plot/surf such unknown funktions?
[X,Y] = meshgrid(-2:.2:2, -4:.4:4); Z = X .* exp(-X.^2 - Y.^2); surf(X,Y,Z) Then you might want to shade shading...

14 years ago | 0

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Answered
error in plotting histogram
Hi, one thing you can do: A=[45,90,68]; b = {'jan','feb','mar'}; bar(A) set(gca,'xticklabel',b)

14 years ago | 0

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Answered
Create a Low Pass Filter on Matlabto Eliminate Hight Frequency Component at 3khz (Z function)
Hi, You can use fdesign.lowpass to design your filter at the command line. As Alex said, fdatool gives you an interactive way to...

14 years ago | 0

Answered
Regression error data
Let y = a(:,2); x1 = a(:,1); I'm assuming the 2nd column is the dependent variable and the first column is your pred...

14 years ago | 0

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Answered
Regression error data
Hi, the simple linear regression model is y = beta0 + beta1*x+epsilon where epsilon is the error. But when you fit the model,...

14 years ago | 0

Answered
Signal Processing - Cross-Correlation to obtain Lag times.
Hi, you need to know the sampling interval of course. Here I assume the sampling interval is 1 msec and delay one signal ten sam...

14 years ago | 0

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Answered
Weibull distribution
Hi Ana, did you use fitdist() or wblfit() to get the Weibull parameters? One thing you can do is use qqplot() to examine the fi...

14 years ago | 1

Answered
error processing wavelet3ddemo from help menu
colormap('gray')

14 years ago | 0

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