Project - Data Handling and Interpolation

Project - Data Handling and Interpolation

AIM

To plot a graph of Voltage VS Current and interpolate it to predict for a new set of values.

Code

clear all

clc

% Reading excel file

Data=xlsread('VI.xlsx');

V=Data(:,1); % First Column contains the Voltage values

I=Data(:,2); % Second Column contains the Current values

% Parameters

IR=-17.3:0.1:0.9; % Interpolation Range

LI=interp1(V,I,IR); % Linear Interpolation

SI=interp1(V,I,IR,'spline'); % Spline Interpolation

PI=interp1(V,I,IR,'pchip'); % PCHIP Interpolation

% Plots

% Plot 1

figure(1)

plot(V,I,'o',IR,LI,':.') % Plotting Linear Interpolation

grid

title('Linear Interpolation')

% Plot 2

figure(2)

plot(V,I,'o',IR,SI,':.') % Plotting Spline Interpolation

grid

title('Spline Interpolation')

% Plot 3

figure(3)

plot(V,I,'o',IR,PI,':.') % Plotting PCHIP Interpolation

grid

title('PCHIP Interpolation')

% Final Interpolation

V_new =[-17.2 -13 -11 -9 -6 -1 0.11 0.25 0.5 0.61 0.66]; % New Coltage values

I_new=interp1(V,I,V_new); % Linear Interpolation for Current calculation

figure(4)

plot(V_new,I_new,'o--') % Plotting Linear Interpolation

grid

title('New Value Interpolation')

% Saving Output File

Output_Data=[V_new;I_new]; % Saving Output Matrix

fid=fopen('output.txt','w'); % Writing to text file

fprintf(fid,'%6s %12s\n','Voltage','Current'); % Writing title of the columns

fprintf(fid,'%6.2f %12.2f\n',Output_Data); % Writing Output values

fclose(fid);

Graph

Result