Project - Data Handling and Interpolation

[V,Ia]=meshgrid(-17.3:0.9,-28:7); %to set Voltage and current range

VI=xlsread('VI.xlsx'); %Read data from Excel file VI

V=VI(:,1); %Voltage matrix

Ia=VI(:,2); %Current matrix

I=pinv(Ia); %Inverting the single row matrix for division in Resistance formula

R=V.*I; %Resistance formula to use for relation

figure(1); surf(V,I,R); %Assigning firgure 1 to Known data plot

xlabel('Voltage');

ylabel('Current');

[Xq,Yq]=meshgrid(-17.3:0.1:0.9,-28:0.19:7); %Putting X and Y limits for interpolation

Vi=interp2(V,Ia,R,Xq,Yq); %Interpolation

figure(2);surf(Xq,Yq,Vi); %Assigning figure 2 for interpolated plot

title('Interpolation');

fid=fopen("Interpolated.txt",'w'); %Opening a text file to input the data

len=length(Vi); %Reading the length matrix Vi

for i=1:len %Running for loop for writting

fprintf(fid,'%d ',Vi(i)); %Writting data

end %Ending the process

fclose(fid); %closing the file

The issue I faced was in the interp2 function which gave an error.