Project - Data Handling and Interpolation

Answer:

Aim:

• To read the excel file given
• To perform the interpolation in the range of -17.3:0.1:0.9.
• Generate the interactive plot for the interpolated data and store them in a text file

Code:

clear;

clc;

% interpolation of voltage and current data

D=xlsread('VI');% reading excel file data

x=D(:,1); % voltage data seperating

y=D(:,2); % current data seperating

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

yq1=interp1(x,y,xq); % linear interpolation

yq2=interp1(x,y,xq,'spline'); % spline interpolation

figure(1)% Linear interpolation plotting

plot(x,y,'o',xq,yq1,':');grid on;

title('Linear Interpolation');

xlabel('Voltage (V)');ylabel('Current (I)');

legend('Actual Value', 'Interpolated value', 'location','northwest');

figure(2)% spline interpolation plotting

plot(x,y,'o',xq,yq2,':');grid on;

title('Spline Interpolation');

xlabel('Voltage (V)');ylabel('Current (I)');

legend('Actual Value', 'Interpolated value', 'location','Northwest');

% saving the interpolation data into text file

%opening text file

v_i_out=fopen('VI_output.txt','w');

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

%writing voltage & current value

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

%'savefig'command is used to save the figures

savefig(1,'linear.fig');savefig(2,'spline.fig');

fclose(v_i_out);