Project - Data Handling and Interpolation

data = xlsread("VI.xlsx"); % Reading the excel data into MATLAB

V = data(:,1); % Separating the Voltage and Current values

I = data(:,2);

range = -17.3:0.1:0.9; % Range of Voltage values for which Current values need to be interpolated

I_interpolated_lin = interp1(V,I,range); % Default Linear Interpolation

I_interpolated_spl = interp1(V,I,range,'spline'); % Spline Interpolation

fileID_lin = fopen("linearInterpolated_data.txt",'w'); % Creating a file ID for the file 'linearInterpolated_data.txt' with 'write' permission

fprintf(fileID_lin,'%4.4f \n',I_interpolated_lin); % Saving the interpolated current data

fclose(fileID_lin); % Closing the file ID having written the required data

fileID_spl = fopen("splineInterpolated_data.txt",'w');

fprintf(fileID_spl,'%4.4f \n',I_interpolated_spl);

fclose(fileID_spl);

% Plotting the original and Linear interpolated data together

figure(1)

plot(V,I,'ro',range, I_interpolated_lin,'b-')

title('Linear Interpolation')

xlabel('Voltage [Volt]')

ylabel('Current [mAmp]')

legend('Original Data','Linear Interpolated Data','Location','southeast')

% Plotting the original and Spline interpolated data together

figure(2)

plot(V,I,'m+',range,I_interpolated_spl,'b-')

title('Spline Interpolation')

xlabel('Voltage [Volt]')

ylabel('Current [mAmp]')

legend('Original Data','Spline Interpolated Data','Location','southeast')