zoukankan      html  css  js  c++  java
  • S变换画图

    The S -transform with windows of arbitrary
    and varying shape

    想画如上的三张图,可是问题

    (1)滤波窗口的平滑实现

    The filter (applied to the full 200£400 S-transform matrix)
    is constructed in Matlab by constructing a two-dimensional
    “boxcar”, using
    filter = zeros(200,400);
    filter(69:128,180:240)=1;
    The filter edges are then smoothed by setting the value of
    each pixel equal to the average of its four adjacent pixels (this
    procedure is repeated 100 times).

    (2)S变换中的频率与短时傅里叶变换频率怎么对应

    我画出来的频率不太对。。边缘也还没处理。。

    clear all
    % x1=readEIS('35006_6_2121_秒.txt');
    % x=x1(:,2);
    x1=load('qzh_3.txt');
    % x=qzh_3;
    
    points=length(x1);
    figure
    subplot(211),plot(0:0.02:0.02*(points-1),x1);title('原始信号');grid on; 
    
    
     [st_matrix,st_times,st_frequencies] = st(x1) ;
    %  imagesc(st_times,st_frequencies,abs(st_matrix))
    % imcontour(abs(st_matrix))
    ST=abs(st_matrix);
    filter = zeros(1501,3000);
    filter(100:800,900:1400)=1;
    STF=ST.*filter;
    STF(STF==0) = NaN;
    subplot(212),h=imagesc(STF);%其中C为包含有nan的数据
    set(h,'alphadata',~isnan(STF))
    ylim([0 1000])
    % set(gca, 'ydir', 'reverse');
    colorbar
    colormapeditor
    

      

     

  • 相关阅读:
    使用ab进行页面的压力测试
    apache http server2.2 + tomcat5.5 性能调优
    php Try Catch多层级异常测试
    用flask实现的添加后保留原url搜索条件
    会议室预定设计
    day4
    day3
    day2
    day1
    redis介绍以及安装
  • 原文地址:https://www.cnblogs.com/gisalameda/p/9090004.html
Copyright © 2011-2022 走看看