MATLAB: How to ignore interp1 method if there is no data in extrated area.

if no dataignoreinterp1random extracted data

Hi
I am extracting 10 database from certain big area data and putting all 10 database in one graph for summing y values. For this I am using interp1 method to put all 10 database in one graph.
So my question is how I deal with interp1 when I have no data in extracted area. It says I need at least 2 point to use interp1 command. Is there any way to give command if my data points 0 or 1 just ignore it or something like this. The thing is I am picking random 10 areas to extract databases and every time I get different points in extracted areas.
% input data [NUMERIC,TXT,RAW]=XLSREAD('sihex.xlsx'); L=xlsread('damL.xlsx'); %%%%%% latitude a = 44; b = 47.5; r = (b-a).*rand(10,1) + a;
%%%%%%% longitude
c = 6.5; d = 7.5; k = (d-c).*rand(10,1) +c;
x=NUMERIC(:,5); y=NUMERIC(:,4); Mag=NUMERIC(:,9);
for iii=1:length(TXT); date_str(iii,:)=TXT(iii,2); end
date_num=datenum(date_str,'dd/mm/yyyy'); test_data11=datenum('01/01/1959','dd/mm/yyyy'); test_data12=datenum('01/01/1979','dd/mm/yyyy'); test_data21=datenum('01/01/1960','dd/mm/yyyy'); test_data22=datenum('01/01/1980','dd/mm/yyyy'); test_data31=datenum('01/01/1961','dd/mm/yyyy'); test_data32=datenum('01/01/1981','dd/mm/yyyy'); test_data41=datenum('01/01/1961','dd/mm/yyyy'); test_data42=datenum('01/01/1981','dd/mm/yyyy'); test_data51=datenum('01/01/1962','dd/mm/yyyy'); test_data52=datenum('01/01/1982','dd/mm/yyyy'); test_data61=datenum('01/01/1965','dd/mm/yyyy'); test_data62=datenum('01/01/1985','dd/mm/yyyy'); test_data71=datenum('01/01/1966','dd/mm/yyyy'); test_data72=datenum('01/01/1986','dd/mm/yyyy'); test_data81=datenum('01/01/1968','dd/mm/yyyy'); test_data82=datenum('01/01/1988','dd/mm/yyyy'); test_data91=datenum('01/01/1968','dd/mm/yyyy'); test_data92=datenum('01/01/1988','dd/mm/yyyy'); test_data101=datenum('01/01/1968','dd/mm/yyyy'); test_data102=datenum('01/01/1988','dd/mm/yyyy');
condition11=(Mag >= 2.5 & date_num > test_data11 & date_num < test_data12 & x > k(1,1)-L(1,1) & x < k(1,1)+L(1,1) & y > r(1,1)-L(1,1) & y < r(1,1)+L(1,1)); g11=ones(size(date_num(condition11)));
condition21=(Mag >= 2.5 & date_num > test_data21 & date_num < test_data22 & x > k(2,1)-L(2,1) & x < k(2,1)+L(2,1) & y > r(2,1)-L(2,1) & y < r(2,1)+L(2,1)); g21=ones(size(date_num(condition21)));
condition31=(Mag >= 2.5 & date_num > test_data31 & date_num < test_data32 & x > k(3,1)-L(3,1) & x < k(3,1)+L(3,1) & y > r(3,1)-L(3,1) & y < r(3,1)+L(3,1)); g31=ones(size(date_num(condition31)));
condition41=(Mag >= 2.5 & date_num > test_data41 & date_num < test_data42 & x > k(4,1)-L(4,1) & x < k(4,1)+L(4,1) & y > r(4,1)-L(4,1) & y < r(4,1)+L(4,1)); g41=ones(size(date_num(condition41)));
condition51=(Mag >= 2.5 & date_num > test_data51 & date_num < test_data52 & x > k(5,1)-L(5,1) & x <k(5,1)+L(5,1) & y > r(5,1)-L(5,1) & y < r(5,1)+L(5,1)); g51=ones(size(date_num(condition51)));
condition61=(Mag >= 2.5 & date_num > test_data61 & date_num < test_data62 & x > k(6,1)-L(6,1) & x < k(6,1)+L(6,1) & y > r(6,1)-L(6,1) & y < r(6,1)+L(6,1)); g61=ones(size(date_num(condition61)));
condition71=(Mag >= 2.5 & date_num > test_data71 & date_num < test_data72 & x > k(7,1)-L(7,1) & x < k(7,1)+L(7,1) & y > r(7,1)-L(7,1) & y < r(7,1)+L(7,1) ); g71=ones(size(date_num(condition71)));
condition81=(Mag >= 2.5 & date_num > test_data81 & date_num < test_data82 & x > k(8,1)-L(8,1) & x < k(8,1)+L(8,1) & y > r(8,1)-L(8,1) & y < r(8,1)+L(8,1)); g81=ones(size(date_num(condition81)));
condition91=(Mag >= 2.5 & date_num > test_data91 & date_num < test_data92 & x > k(9,1)-L(9,1) & x < k(9,1)+L(9,1) & y > r(9,1)-L(9,1) & y < r(9,1)+L(9,1)); g91=ones(size(date_num(condition91)));
condition101=(Mag >= 2.5 & date_num > test_data101 & date_num < test_data102 & x > k(10,1)-L(10,1) & x < k(10,1)+L(10,1) & y > r(10,1)-L(10,1) & y < r(10,1)+L(10,1)); g101=ones(size(date_num(condition101)));
all_times = unique([date_num11; date_num21; date_num31; date_num41;date_num51;date_num61;date_num71;date_num81;date_num91;date_num101;]); P11=date_num11; uniq = [true; diff(P11) ~= 0]; first_projected = interp1(P11(uniq), g11(uniq), all_times); P21=date_num21; uniq = [true; diff(P21) ~= 0]; second_projected = interp1(P21(uniq), g21(uniq), all_times); P31=date_num31; uniq = [true; diff(P31) ~= 0]; third_projected = interp1(P31(uniq), g31(uniq), all_times); P41=date_num41; uniq = [true; diff(P41) ~= 0]; forth_projected = interp1(P41(uniq), g41(uniq), all_times); P51=date_num51; uniq = [true; diff(P51) ~= 0]; fifth_projected = interp1(P51(uniq), g51(uniq), all_times); P61=date_num61; uniq = [true; diff(P61) ~= 0]; six_projected = interp1(P61(uniq), g61(uniq), all_times); P71=date_num71; uniq = [true; diff(P71) ~= 0]; seven_projected = interp1(P71(uniq), g71(uniq), all_times); P81=date_num81; uniq = [true; diff(P81) ~= 0]; eigth_projected = interp1(P81(uniq), g81(uniq), all_times); P91=date_num91; uniq = [true; diff(P91) ~= 0]; ninth_projected = interp1(P91(uniq), g91(uniq), all_times); P101=date_num101; uniq = [true; diff(P101) ~= 0]; ten_projected = interp1(P101(uniq), g101(uniq), all_times);
first_projected(isnan(first_projected)) = 0; second_projected(isnan(second_projected)) = 0; third_projected(isnan(third_projected)) = 0; forth_projected(isnan(forth_projected)) = 0; fifth_projected(isnan(fifth_projected)) = 0; six_projected(isnan(six_projected)) = 0; seven_projected(isnan(seven_projected))=0; eigth_projected(isnan(eigth_projected)) = 0; ninth_projected(isnan(ninth_projected)) = 0; ten_projected(isnan(ten_projected)) = 0;
data_total = first_projected + second_projected+third_projected+forth_projected+fifth_projected+six_projected+seven_projected+eight_projected+ninth_projected+ten_projected; figure; plot(all_times,data_total); hold on; Thanks!

Best Answer

You deal with it by looking at length() of your proposed input before the call and making a decision about what you want the result to be if you have 0 or 1 points. This is not something that interp1() can handle for you.