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Showing posts from September, 2021

Convolution of two signals using conv() in Matlab

We use the conv(x1,x2) function in Matlab to perform convolution of two discrete signals. For example, to perform the convolution of two discrete time sequences x1 (n) = {1, 0, 1,2}  and x2 (n) = {1, 2, 4, 6}. Code:  x1=[1,0,1,2]; %1st sequence N1=length(x1); %stores length of 1st sequence n1=0:1:N1-1; %range of x axis for 1st graph of 1st sequence subplot(1,3,1); % in a 1x3 grid, 1st sequence occupies the 1st grid stem(n1,x1,'linewidth',1.5); %to plot the sequence specifying time axis, signal and line width xlabel('n1----->'); %title of x axis ylabel('x1----->'); %title of y axis grid on; x2=[1,2,4,6]; %2nd sequence N2=length(x2);    %stores length of 2nd sequence n2=0:1:N2-1;  %range of x axis for 2nd graph of 2nd sequence subplot(1,3,2);  % in a 1x3 grid, 2nd sequence occupies the 2nd grid stem(n2,x2,'red','linewidth',1.5);  %to plot the sequence specifying time axis,signal,line width and colour xlabel('n2----->'); % title of

A Night without Electricity

It was raining heavily as I hurriedly ran towards my flat in Southern Park. It was already eleven when I was returning home after work. I soon realised by the darkness of the lane that there was a power cut in the locality which made it very difficult to find my way.  Adapting my eyes to the darkness of the lane, I strode along the path I knew so well. I quickly opened the door and entered the apartment. It was a three storey building, the ground floor was Dr. Kunal's Chamber and the first floor belonged to Mr. Bose while I lived on the second floor.  As I entered I could see a faint light coming from a candle burning in the doctor's cabin and feeling for the stair case in the dark , I slowly started to climb the stairs. There was an empty bird cage at the door of Mr. Bose who was a bird lover and would often go to the nearest lake with his DSLR camera early in the morning hoping to take a snap of  the river kingfisher or the common emerald dove. So carefully passing by the cag

How to plot a Continuous Time Sequence and Discrete Time Sequence in Matlab

1. For Continuous Time Sequence:        Use the function:  plot(X-axis, Y-axis)          For example to plot a parabolic function p(t)=  At^2 for t>=0                                                                                    0        for t<0           Code:           %UNIT PARABOLIC FUNCTION t=linspace(-20,20,20);      %range of X-asis A=1;                  %amplitude of the function for A=1 it is called unit parabolic function p=[t>=0].*(A.*t.^2)/2;      %parabola equation as defined above subplot(1,2,1);                  %the graph occupies 1st position in 1x2 grid plot(t,p); %plot(X-axis is represented here as t, Y-axis is represented by p here) xlabel('t---->')                  %naming the x-axis in the graph ylabel('p(t)---->');            %naming the y-axis in the graph title('Unit parabolic Signal'); %title of the graph grid on;   The output graph is shown below:   2.  For Discrete Time Sequence:         Use the function:   stem(