How to select the range of data based on threshold range of our own choice?

2 次查看（过去 30 天）
Amjad Iqbal
Amjad Iqbal 2022-9-20
评论： Amjad Iqbal 2022-9-20
Dear MATLAB experts,
I want to use only the points corresponding to relatively high amplitudes? (e.g., try -10 to 0 dB or -20 to -10 dB or -30 to -20 on the normalized plots).
In attached imaging data output which veries from -45 to 0 dB.
I want to make 3 classes and plot data in with 3 classes and 3 colors.
.
I lookforward to receive your suggestions. I tried an approach but it gives logical output which is not suitable for my case.
Tahnk you!
  2 个评论
Image Analyst
Image Analyst 2022-9-20
You can adapt the colormap to have only 3 colors. Please attach your original image varible in a .mat file if you want anybody to try anything. What do you want to be the color if the value is outside your ranges? Why do your three ranges (-10 to 0 dB, or -20 to 10 dB, or -30 to -10) overlap? For example a -15 : which class should it be in the second or the third???
Amjad Iqbal
Amjad Iqbal 2022-9-20
@Image Analyst
Sorry, for my mistake.
I corrected the ranges (-10 to 0 dB or -20 to -10 dB or -30 to -20) in three classes now, as high, medium and low respectively.
Also the .mat file is attached for reference.
load('output_classes.mat'); % data
imagesc(x_vect, y_vect,20*log10(abs(S_VH)/max(max(abs(S_VH)))),[-45 0]),...
axis('equal'),axis('tight'),title('Output'),colormap('jet'),...
colorbar,set(gca,'FontSize',14),grid;
Please have a look, Thank you!

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Image Analyst
Image Analyst 2022-9-20
Ran in:
Try this:
load('output_classes.mat'); % data
intensity = 20*log10(abs(S_VH)/max(max(abs(S_VH))));
imagesc(x_vect, y_vect, intensity,[-45 0]);
axis('equal');
axis('tight');
title('Output');
cmap = [0,0,0;
1,0,0;
0,1,0;
0,0,1
]
cmap = 4×3
0 0 0 1 0 0 0 1 0 0 0 1
colormap(cmap);
colorbar;
caxis([-40, 0]);
set(gca,'FontSize',14)
grid;

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Deep Learning Toolbox 的更多信息

标签

产品


版本

R2021a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by