how to unite two curves smoothly in matlab?

Hello,

I have two distinct curves, sharing one data point in common. I would like to join/unite these curves in a plot, without repeating the same data point. Additionally, I want to get rid of the spike @ 15.2 Here is the excel that I read the data from, and the fig output. If anyone would help me please??

In the excel;

Column A and B shows the data of the first curve, x and y respectively.

Column D and E shows the data of the second curve, x and y respectively.

Column G and H shows the united data, x and y data. On the rows of 1001 and 1002, data at 15.2 is repeated. Even tough I eliminate one row, I do not know how to smooth the region of 15.2. Hope there is a smarter way than deleting some points and interpolating with new ones.

Your helps would be more than apprecitated..

clc
clear all
close all

Ku_eGR_IL_WG_S21=xlsread('Ku_eGR_IL_WG.xlsx','H:H'); % A S21 magnitude
frequency=xlsread('Ku_eGR_IL_WG.xlsx','G:G'); % frequency

plot(frequency,Ku_eGR_IL_WG_S21,'LineWidth',2);
grid on
grid minor
xlabel('Frequency (GHz)');
ylabel('Insertion S21 (dB)');
title(' Ku eGR IL WG ');
legend('eGR IL');
set(gca,'FontSize',15,'fontweight','bold')
xlim([12 18.4]);

Answer 1

[Davide Masiello]

This should work

clc, clear, clf

Ku_eGR_IL_WG_S21 =xlsread('Ku_eGR_IL_WG.xlsx','H:H'); % A S21 magnitude
frequency =xlsread('Ku_eGR_IL_WG.xlsx','G:G'); % frequency

[frequency,idx,idx2] = unique(frequency);
Ku_eGR_IL_WG_S21 = Ku_eGR_IL_WG_S21(idx);

jump = Ku_eGR_IL_WG_S21(find(~diff(idx2)))-Ku_eGR_IL_WG_S21(find(~diff(idx2))+1);
Ku_eGR_IL_WG_S21(find(~diff(idx2))+1:end) = jump+Ku_eGR_IL_WG_S21(find(~diff(idx2))+1:end);

plot(frequency,Ku_eGR_IL_WG_S21,'LineWidth',2);
grid on
grid minor
xlabel('Frequency (GHz)');
ylabel('Insertion S21 (dB)');
title(' Ku eGR IL WG ');
legend('eGR IL');
set(gca,'FontSize',15,'fontweight','bold')
xlim([12 18.4]);

[Zeynep Ertekin]

thank you for the help! but it stayed the same :(

[Davide Masiello]

I checked it on my machine.

My code eliminates the repeated frequency value, but then you have another point at a frequency immediately larger (15.2032) and with a different y-value, which causes the spike.

What would you like to do about that exactly?

[Zeynep Ertekin]

I would like to get rid of the spike within that range, I would prefer smooth connection.

[Davide Masiello]

How exactly?

Would you lower all the values in the second dataset of a certain constant, so that it looks smoother?

[Zeynep Ertekin]

The method does not matter, however possible it is, it is ok for me, I just dont know the method.

[Davide Masiello]

I edited the answer, see if it suits your need better now.

[Zeynep Ertekin]

Sorry, I was so excited that, I have forgotten answer. It worked!!! thanks a lot, mille grazie per tutti gli autarmi

[Star Strider]

@Zeynep Ertekin — Since the answer worked, it is appropriate to Accept it.

[Zeynep Ertekin]

Hey! I didn't know that I should have accepted it, thanks a lot!