How can i mark the data points in the graph?

I've plotted this figure. Now i want to mark the corresponding points. my code is

clc;
close all;
clear all;

x=[0:1:12];
SWR_Ratio=[1,1.28,1.8,2.5,3.2,4.2,5.4,7.25,10,11.32,11.8,12.85,20];
SWR_Deflection=[0,2.2,5,7.5,10,12.5,14.5,17.5,20,22.2,25.1,28.5,30];
figure(1)
subplot('211')
loglog(x,SWR_Ratio,'r')
title('Standing Wave Ratio (SWR) vs Attenuation')
xlabel('Attenuation(dB)')
ylabel('SWR')
grid on
subplot('212')
semilogx(x,SWR_Deflection)
title('SWR deflection vs Attenuation')
% legend('semilogx')
xlabel('Attenuation(dB)')
ylabel('SWR deflection')
axis([0 100 0 100])

Answer 1

[Star Strider]

You do not say how you want to ‘mark the corresponding points’.

Two possibilities:

One is to include a marker with the plot:

loglog(x,SWR_Ratio,'-rp')

and:

semilogx(x,SWR_Deflection, '-p')

Another is to use a text (link) object. See the documentation for details.

[Md Monirul Islam]

thanks for your answer. but i was looking for pinpointing each data with label. e.g. for the first data point (0,1) of figure 1, i want the point be labeled as (0,1) so that i can see what that point refers to in my data.

[Star Strider]

My pleasure.

Use the text function for that. (I already linked to it in my original Answer.) It has a number of name-value pairs that will allow you align each one correctly.

This works:

x=[0:1:12];
SWR_Ratio=[1,1.28,1.8,2.5,3.2,4.2,5.4,7.25,10,11.32,11.8,12.85,20];
SWR_Deflection=[0,2.2,5,7.5,10,12.5,14.5,17.5,20,22.2,25.1,28.5,30];

figure(1)
subplot('211')
loglog(x,SWR_Ratio,'r')
title('Standing Wave Ratio (SWR) vs Attenuation')
xlabel('Attenuation(dB)')
ylabel('SWR')
grid on
pt_str = sprintf('(%d,%g)\n', [x(:) SWR_Ratio(:)]');
pt_cell = regexp(pt_str, '\n', 'split');
text(x, SWR_Ratio, pt_cell(1:end-1), 'HorizontalAlignment','left', 'VerticalAlignment','bottom', 'FontSize',8)

subplot('212')
semilogx(x,SWR_Deflection)
title('SWR deflection vs Attenuation')
% legend('semilogx')
xlabel('Attenuation(dB)')
ylabel('SWR deflection')
axis([0 100 0 100])
pt_str = sprintf('(%d,%g)\n', [x(:) SWR_Deflection(:)]');
pt_cell = regexp(pt_str, '\n', 'split');
text(x, SWR_Deflection, pt_cell(1:end-1), 'HorizontalAlignment','left', 'VerticalAlignment','bottom', 'FontSize',8)

The ‘pt_str’ assignment creates the point label string, ‘pt_cell’ creates a cell array from them because the text function wants them as a cell array (the last entry is blank, so I removed it with the ‘(1:end-1)’ subscript reference), and the text call plots the labels.

You will have to experiment to get the labels to display as you want them to.