Project - Data Handling and Interpolation

clc

data=xlsread("VI.xlsx"); % reading excel file data

V=data(:,1); % To seperate voltage data

I=data(:,2); % To seperate current data

xq=[-17.3:0.1:0.9]; % interpolation range

yq1=interp1(V,I,xq); % linear interpolation

yq2=interp1(V,I,xq,'spline'); % spline interpolation

figure(1) %Linear interpolation plot

plot(V,I,'O',xq,yq1,'g: .');

title('Linear Interpolation');

xlabel('Voltage[V]');

ylabel('Current[I]');

legend('actual value','interpolated value','location','south east');

grid on;

figure(2) %spline interpolation plot

plot(V,I,'O',xq,yq2,'b: .');

title('spline Interpolation');

xlabel('Voltage[V]');

ylabel('Current[I]');

legend('actual value','interpolated value','location','south east');

grid on

% interpolation data into text file

FILE=fopen('VI.txt','w');

fprintf(FILE,'Voltage Current\n');

fprintf(FILE,'%4.3f %5.3f\n',xq,yq2);

savefig(1,'VIlinearplot.fig'); %to save linear interpolation graph

savefig(2,'VIsplinerplot.fig'); %to saving spline interpolation graph

fclose(FILE);

result=interp1(V,I,'linear','extrap')

% to find missing data and save it in text

z=[xq yq1 yq2];

writematrix(z,'Project.txt')

MATLAB_PROJECT_INTPLN

result =

-23.1000
-22.3000
-21.3000
-20.3000
-19.3000
-18.7000
-18.3000
-18.1000
-17.9000
-17.7600
-17.7000
-17.6200
-17.5600
-17.5200
-17.5000
-17.5000
-17.5000
-17.4980
-17.4940
-17.4660
-17.4160
-17.2540
-17.1020
-16.8180

Interpolation is a method of fitting the data points to represent the value of a function. It has various applications in engineering and science, that are used to construct new data points within provided range of a discrete data set of known data points.

A: LINEAR INTERPOLATION

A linear interpolation is a form of interpolation, which involves the generation of new values based on an existing set of values.

B: SPLINE INTERPOLATION

By using given data(voltage and current ) and performed linear interpolation and spline interpolation which can be seen in genearted waveform.