Project - Data Handling and Interpolation

V (Volt)	I (mAmp)
-17.3	-28
-17.1	-24
-17	-19
-16.8	-14
-16.5	-9
-16	-6
-15	-4
-14	-3
-12	-2
-10	-1.3
-8	-1
-5	-0.6
-2	-0.3
-0.2	-0.1
0.09	0
0.19	0
0.27	0
0.39	0.01
0.43	0.03
0.5	0.17
0.55	0.42
0.6	1.23
0.62	1.99
0.65	3.91

Reading the spreadsheet file in MatLab

>> VI=xlsread('VI.xlsx')

VI =

-17.3000 -28.0000
-17.1000 -24.0000
-17.0000 -19.0000
-16.8000 -14.0000
-16.5000 -9.0000
-16.0000 -6.0000
-15.0000 -4.0000
-14.0000 -3.0000
-12.0000 -2.0000
-10.0000 -1.3000
-8.0000 -1.0000
-5.0000 -0.6000
-2.0000 -0.3000
-0.2000 -0.1000
0.0900 0
0.1900 0
0.2700 0
0.3900 0.0100
0.4300 0.0300
0.5000 0.1700
0.5500 0.4200
0.6000 1.2300
0.6200 1.9900
0.6500 3.9100

Giving names and saving datas as first column Voltage and second column as Amps

>> Voltage=VI(:,1);
>> Amps=VI(:,2);

Applying range
>> range=-17.3:0.1:0.9;

Applying interplation1 to get 2D Image
>> yq1=interp1(Voltage,Amps,range);

Plotting VI graph and applying values  

>> figure(1);plot(Voltage,Amps,'*');grid;
>> title('V vs I');
>> ylabel('I(mAmps)');
>> xlabel('V(volt)');

Saving figure1 as pdf
>> print('V vs I','-dpdf');

Plotting range vs interpolation1 graph and applying values  
>> figure(2);plot(range,yq1,'*');grid;
>> title('Range vs Interpolation1');
>> ylabel('I(mAmps)');
>> xlabel('V(volt)');

Saving figure2 as pdf
>> print('Range vs Interpolation','-dpdf');

Plotting Fig1 & Fig2 summation graph and applying values  

>> figure(3);plot(Voltage,Amps,'*',range,yq1);grid;
>> title('Fig1 & Fig2 summation');
>> ylabel('I(mAmps)');
>> xlabel('V(volt)');

Saving figure3 as pdf
>> print('Fig1 & Fig2 summation','-dpdf');

Data Given
>> VV=[-17.2 -17.1 -13.8 -13.5 -13.0 -12.5 -11 -9 -5.76 -6 -1 0.11 0.25 0.5 0.61]

VV =

Columns 1 through 5

-17.2000 -17.1000 -13.8000 -13.5000 -13.0000

Columns 6 through 10

-12.5000 -11.0000 -9.0000 -5.7600 -6.0000

Columns 11 through 15

-1.0000 0.1100 0.2500 0.5000 0.6100

>> legend('VI data','VI interpolated data');

Applying Spline Interpolation
>> yq2=interp1(Voltage,Amps,VV,'spline');

Plotting Given Data (VV) vs Interpolated Data  graph and applying values  
>> figure(4);plot(VV,yq2,'*',range,yq1);grid;
>> title('VV vs VI');
>> ylabel('I(mAmps)');
>> xlabel('V(volt)');
>> title('Given Data VV vs Interpolated Data');
>> legend('Given data','Interpolated data');

Saving figure4 as pdf
>> print('Given Data VV vs Interpolated Data','-dpdf');

Savng the values into a text file

File opening

>> fid=fopen('VI.txt','w');

Giving Headings as Volt and Amps
>> fprintf(fid,'V(Volt) I(Amps)\n');
>> len=length(VV);

\n for next line,%f is used instead of %d to get decimal values
>> for i=1:len, fprintf(fid,'%f %f\n',VV(i),yq2(i));
end;

File closing
>> fclose(fid);

Given VV is denoted as Volt

    V(Volt)            I(Amps)

-17.20000   -28.173426

-17.10000   -24.000000

-13.80000   -2.868222

-13.50000   -2.688869

-13.00000   -2.429766

-12.50000   -2.205780

-11.00000    -1.610323

-9.000000    -1.116443

-5.760000    -0.710517

-6.000000    -0.744512

-1.000000    -0.290596

0.110000      0.001150

0.250000     -0.000137

0.500000      0.170000

0.610000      1.566533