1、代码:
从MATLAB官方网上下载的。
%*************************************************************************% %A code for the Downsampler% %Author: Yashwant Marathe% %Date:20-12-2010% function [y ny] = dnsample(x,n,M) %x is a sequence over indices specified by vector n,M is the downsampling factor. param=n/M; %generates the parameter vector.This vector will decide which input samples will be present in the output. samp=fix(param)==param; %only those output vectors corresponding to indices where samp==1 will be present in the output. y=x(samp==1); %generates the output sequence ny=n(samp==1)/M; %generates the indices of the output sequence end %**************************************************************************
2、代码
%% ------------------------------------------------------------------------ %% Output Info about this m-file fprintf(‘\n***********************************************************\n‘); fprintf(‘ <DSP using MATLAB> Problem 2.8.2 \n\n‘); banner(); %% ------------------------------------------------------------------------ n = [-50:1:50]; x = sin( 0.125 * pi * n ); M = 4; [y, m] = dnsample(x, n, M); figure(‘NumberTitle‘, ‘off‘, ‘Name‘, ‘Problem 2.8.2‘) set(gcf,‘Color‘,[1,1,1]) % 改变坐标外围背景颜色 subplot(2,1,1); stem(n, x); title(‘x sequence‘); xlabel(‘n‘); ylabel(‘x(n)‘) ; grid on subplot(2,1,2); stem(m, y); title(‘y sequence‘); xlabel(‘n‘); ylabel(‘y(m)‘); grid on;
运行结果:
3、代码
%% ------------------------------------------------------------------------ %% Output Info about this m-file fprintf(‘\n***********************************************************\n‘); fprintf(‘ <DSP using MATLAB> Problem 2.8.3 \n\n‘); banner(); %% ------------------------------------------------------------------------ n = [-50:1:50]; x = sin( 0.5 * pi * n ); M = 4; [y, m] = dnsample(x, n, M); figure(‘NumberTitle‘, ‘off‘, ‘Name‘, ‘Problem 2.8.3‘) set(gcf,‘Color‘,[1,1,1]) % 改变坐标外围背景颜色 subplot(2,1,1); stem(n, x); title(‘x sequence‘); xlabel(‘n‘); ylabel(‘x(n)‘) ; grid on subplot(2,1,2); stem(m, y); title(‘y sequence‘); xlabel(‘n‘); ylabel(‘y(m)‘); grid on;
运行结果:
时间: 2024-10-11 14:14:55