Community Profile

# PChoppala

### UNSw

51 total contributions since 2011

My research interests include Bayesian statistics, spatial modelling, machine learning, stochastic signal processing and particle filtering.

Contributions in
View by

Question

covariance of weighted multidimensional samples
I have a multidimensional weighted sample set, e.g. D=2; % dimension N=100; % number of samples x=randn(D,N); % samples ...

5 months ago | 0 Answers | 0

### 0

Question

sampling from a normal distribution
I usually generate a sample from a normal distribution N(mu,sigmasq) (where mu is the mean and sigmasq is the variance) as follo...

8 months ago | 0 Answers | 0

### 0

Define a matrix A of dimension 2*4 whose (i , j) entry is A(i , j)=i+j
[P1,P2]=meshgrid(1:4,1:2) result=P1+P2

1 year ago | 0

I can't put two lines in one legend on matlab in my plot
string1 = 'xyz'; string2 = 'abc'; value=3.14; sprintf('%.2f %s %s \n %s',value,string1,string2,string2)

1 year ago | 0

Problem with legend in a plot
An example (although there are better ways of doing it), n=50; x=linspace(1/n,1,n); y1=sin(4*pi*x); y2=cos(4*pi*x(10:3...

1 year ago | 0

object detection from frames
This is not a MATLAB specific question. Look here <http://au.mathworks.com/discovery/object-recognition.html> or try machine lea...

1 year ago | 0

Question

accessing elements inside cell arrays
I am not a great user of cell arrays and haven't found my answer precisely on other links, hence the question. I have a cell arr...

1 year ago | 1 Answers | 0

### 1

Question

Color coding commented statements and comments following a statement
Hi, I would like to know if there is a possibility of having a different color for a commented statement and a comment that ...

1 year ago | 0 Answers | 0

### 0

Question

plotting with different colors
Hi, I have to plot something like x=0.1:0.1:1; n=length(x); f=exp(x); y=f+0.1*randn(1,n); figure ...

1 year ago | 1 Answers | 0

### 1

Question

Bar plot with a single bar across multiple x-axis values
I need to plot a single horizontal bar across multiple x-axis values, e.g., y=[2 1 3]; bar(1:6,y(1),'c', 2:5,y(2)...

2 years ago | 1 Answers | 0

### 1

Question

using rand to generate numbers
Hi I have a simple question. I understand that both a and b vectors (please see below) will generate 5 random numbers from 0 ...

3 years ago | 2 Answers | 0

### 2

Question

cdf of multivariate normal random numbers
Hi I want to find the cdf of a set of 1000 bivariate normal random numbers that are generated by X=mvnrnd([3,12],[1,.2;....

3 years ago | 1 Answers | 0

### 1

Question

finding the starting points of the steps in a staircase like function
Hi I will appreciate help on this problem: I generate a vector C from a set of weighted samples (you can see in the figure...

3 years ago | 1 Answers | 0

### 1

Question

Sharing the values between vectors
Hi I will appreciate your support on this: I have a 3 x 9 matrix f with some finite and non-finite values. I have to manip...

3 years ago | 1 Answers | 0

### 1

Question

integrating the product of two pdf's
Hi I have a small query, and will appreciate your help. I am supposed to find the integral of the product of two probabil...

4 years ago | 2 Answers | 0

### 2

Question

bimodal Gaussian distribution function
Hi Greetings. I have a simple problem and will appreciate your help. I am trying to plot the bimodal Gaussian distribution...

4 years ago | 2 Answers | 0

### 2

Question

filter, decay, delayed versions
Hello everyone, I need advice on a simple query. I need a FIR filter which has decay time specified by me. The filter...

4 years ago | 1 Answers | 0

### 1

Question

finding multiple maxima in a Gaussian distribution
Hi I have a query and will appreciate your help. If we try the code below, >> c1=1; >> for p=-50:50 c2=1; fo...

4 years ago | 2 Answers | 0

### 2

Question

round, randn
Hello Simple query. Suppose I assign y=randn(4,1), I get a 4X1 matrix with random numbers which have (may be) 3-4 number a...

5 years ago | 1 Answers | 0

### 1

Question

reverberation in matlab
Hi I have a broadband signal x(t) as x = randn(1,100); Fs = 48e3; Do we have any inbuilt function or a standard procedur...

5 years ago | 0 Answers | 0

### 0

Question

surf, plotting, axis
Hi Simple question.... I have an output 'P' which is a 10X10 matrix. I start with for i=1:10 for j=1:10 P...

5 years ago | 1 Answers | 0

### 1

Question

fft
Hi Just an urgent but simple question. I have a signal s = randn(1,100), with Fs = 48e3 Hz. I want to add a delay of 1.3ms...

5 years ago | 0 Answers | 0

### 0

Question

upsampling and adding delay to a sequence
Hi I have a simple query. Suppose i have a signal s = randn(1,10), if I want to add delay 100ms to this signal, what sho...

5 years ago | 1 Answers | 0

### 1

Question

Hi Another simple question with regard to my last question on broadband signal delay. Can we treat t=0:1/100:1 s=sin(2*...

5 years ago | 0 Answers | 0

### 0

Question

how to add delay to a signal
Hi I have a small query. Can you help me to add delay to a signal s=randn(1,100); But the delay is given in time domain, ...

5 years ago | 3 Answers | 0

### 3

Question

Hi there For my simulations, I need to generate a broadband signal s(t). Also, at a later stage, I need s(t-D),(I will sep...

5 years ago | 0 Answers | 0

### 0

Responded

how about s=rand(1000,1)-0.5 Uniform or Gaussian gives you a flat spectrum

5 years ago | 2282 views

Question

mathematical expectation
Hi Suppose we have a vector X=[1 2 -1 5 2], I want the mathematical expectation E{x*x'}, can you please help me with that sta...

5 years ago | 2 Answers | 0

### 2

Question

randn, awgn, wgn
Hi I have a small doubt. Is a = awgn(randn(20,20), 6.7) and a = wgn(20,20,6.7) the same Aim is, I want a 20X20 fram...

5 years ago | 1 Answers | 0

### 1

Question

secons max number in a vector
Hi I need to find maximum and second maximum number in a vector. Can you please help? For max, its max(X), but for second max...

5 years ago | 1 Answers | 0