Undefined function or variable

Hi all,

I am calling a function and receiving this error, my dummy_run_check_island.m (main file) is:

clearvars;
tic
load('checkcheck.mat');
tf_result=check_island(lon,lat);

wtime = toc;
fprintf ( 1, 'Program took %f seconds to run.\n', wtime );
 %}

My check_island.m (calling function) is:

 function [output] = check_island(lon,lat)
%Input Lon [-180 180]-format and Lat [-90 90]-format
%lon=-100;
%lat=50;
%lon =133.735508667306;
%lat =47.8022743515138;

if all(lon>=-180.009166666889 & lon <=-149.99083260668) 
    if all(lat<=60.0091668606037 & lat >= 29.9908328003949)
        L = load('110_size.mat');
        check_value = 1;
    elseif all(lat<29.9908328003949 & lat >= -0.00916669110301882)
        L = load('210_size.mat');
        check_value = 1;
    elseif all(lat<-0.00916669110301882 & lat >= -30.009166691103)
        L = load('310_size.mat');
        check_value = 1;
    elseif all(lat<-30.009166691103 & lat >= -60.0091670543188)
        L = load('410_size.mat');
        check_value = 1;
    end
    
elseif all(lon>-149.99083260668 & lon <=-119.99083260668) 
    if all(lat<=60.0091668606037 & lat >= 29.9908328003949)
        L = load('120_size.mat');
        check_value = 1;
    elseif all(lat<29.9908328003949 & lat >= -0.00916669110301882)
        check_value = 2;
    elseif all(lat<-0.00916669110301882 & lat >= -30.009166691103)
        L = load('320_size.mat');
        check_value = 1;
    elseif all(lat<-30.009166691103 & lat >= -60.0091670543188)
        check_value = 2;
    end
    
elseif all(lon>-119.99083260668 & lon <=-89.9908326066798) 
    if all(lat<=60.0091668606037 & lat >= 29.9908328003949)
        L = load('130_size.mat');
        check_value = 1;
    elseif all(lat<29.9908328003949 & lat >= -0.00916669110301882)
        L = load('230_size.mat');
        check_value = 1;
    elseif all(lat<-0.00916669110301882 & lat >= -30.009166691103)
        L = load('330_size.mat');
        check_value = 1;
    elseif all(lat<-30.009166691103 & lat >= -60.0091670543188)
        check_value = 2;
    end
    
elseif all(lon>-89.9908326066798 & lon <=-59.9908326066798) 
    if all(lat<=60.0091668606037 & lat >= 29.9908328003949)
        L = load('140_size.mat');
        check_value = 1;
    elseif all(lat<29.9908328003949 & lat >= -0.00916669110301882)
        L = load('240_size.mat');
        check_value = 1;
    elseif all(lat<-0.00916669110301882 & lat >= -30.009166691103)
        L = load('340_size.mat');
        check_value = 1;
    elseif all(lat<-30.009166691103 & lat >= -60.0091670543188)
        L = load('440_size.mat');
        check_value = 1;
    end 
    
elseif all(lon>-59.9908326066798 & lon <=-29.9908326066798) 
    if all(lat<=60.0091668606037 & lat >= 29.9908328003949)
        L = load('150_size.mat');
        check_value = 1;
    elseif all(lat<29.9908328003949 & lat >= -0.00916669110301882)
        L = load('250_size.mat');
        check_value = 1;
    elseif all(lat<-0.00916669110301882 & lat >= -30.009166691103)
        L = load('350_size.mat');
        check_value = 1;
    elseif all(lat<-30.009166691103 & lat >= -60.0091670543188)
        L = load('450_size.mat');
        check_value = 1;
    end
    
elseif all(lon>-29.9908326066798 & lon <=0.00916736910585314) 
    if all(lat<=60.0091668606037 & lat >= 29.9908328003949)
        L = load('160_size.mat');
        check_value = 1;
    elseif all(lat<29.9908328003949 & lat >= -0.00916669110301882)
        L = load('260_size.mat');
        check_value = 1;
    elseif all(lat<-0.00916669110301882 & lat >= -30.009166691103)
        L = load('360_size.mat');
        check_value = 1;
    elseif all(lat<-30.009166691103 & lat >= -60.0091670543188)
        L = load('460_size.mat');
        check_value = 1;
    end

elseif all(lon>0.00916736910585314 & lon <=30.0091674417288) 
    if all(lat<=60.0091668606037 & lat >= 29.9908328003949)
        L = load('170_size.mat');
        check_value = 1;
    elseif all(lat<29.9908328003949 & lat >= -0.00916669110301882)
        L = load('270_size.mat');
        check_value = 1;
    elseif all(lat<-0.00916669110301882 & lat >= -30.009166691103)
        L = load('370_size.mat');
        check_value = 1;
    elseif all(lat<-30.009166691103 & lat >= -60.0091670543188)
        L = load('470_size.mat');
        check_value = 1;
    end
    
elseif all(lon>30.0091674417288 & lon <=60.0091673933202) 
    if all(lat<=60.0091668606037 & lat >= 29.9908328003949)
        L = load('180_size.mat');
        check_value = 1;
    elseif all(lat<29.9908328003949 & lat >= -0.00916669110301882)
        L = load('280_size.mat');
        check_value = 1;
    elseif all(lat<-0.00916669110301882 & lat >= -30.009166691103)
        L = load('380_size.mat');
        check_value = 1;
    elseif all(lat<-30.009166691103 & lat >= -60.0091670543188)
        L = load('480_size.mat');
        check_value = 1;
    end

elseif all(lon>60.0091673933202 & lon <=90.0091673933202) 
    if all(lat<=60.0091668606037 & lat >= 29.9908328003949)
        L = load('190_size.mat');
        check_value = 1;
    elseif all(lat<29.9908328003949 & lat >= -0.00916669110301882)
        L = load('290_size.mat');
        check_value = 1;
    elseif all(lat<-0.00916669110301882 & lat >= -30.009166691103)
        L = load('390_size.mat');
        check_value = 1;
    elseif all(lat<-30.009166691103 & lat >= -60.0091670543188)
        L = load('490_size.mat');
        check_value = 1;
    end
    
elseif all(lon>90.0091673933202 & lon <=120.00916739332) 
    if all(lat<=60.0091668606037 & lat >= 29.9908328003949)
        L = load('191_size.mat');
        check_value = 1;
    elseif all(lat<29.9908328003949 & lat >= -0.00916669110301882)
        L = load('291_size.mat');
        check_value = 1;
    elseif all(lat<-0.00916669110301882 & lat >= -30.009166691103)
        L = load('391_size.mat');
        check_value = 1;
    elseif all(lat<-30.009166691103 & lat >= -60.0091670543188)
        L = load('491_size.mat');
        check_value = 1;
    end
 
elseif all(lon>120.00916739332 & lon <=150.00916739332) 
    if all(lat<=60.0091668606037 & lat >= 29.9908328003949)
        L = load('192_size.mat');
        check_value = 1;
    elseif all(lat<29.9908328003949 & lat >= -0.00916669110301882)
        L = load('292_size.mat');
        check_value = 1;
    elseif all(lat<-0.00916669110301882 & lat >= -30.009166691103)
        L = load('392_size.mat');
        check_value = 1;
    elseif all(lat<-30.009166691103 & lat >= -60.0091670543188)
        L = load('492_size.mat');
        check_value = 1;
    end
    
elseif all(lon>150.00916739332 & lon <=180.00916739332) 
    if all(lat<=60.0091668606037 & lat >= 29.9908328003949)
        L = load('193_size.mat');
        check_value = 1;
    elseif all(lat<29.9908328003949 & lat >= -0.00916669110301882)
        L = load('293_size.mat');
        check_value = 1;
    elseif all(lat<-0.00916669110301882 & lat >= -30.009166691103)
        L = load('393_size.mat');
        check_value = 1;
    elseif all(lat<-30.009166691103 & lat >= -60.0091670543188)
        L = load('493_size.mat');
        check_value = 1;
    end  
end

% Interpolate method:
if      check_value == 1
    tf = interp2(L.x,L.y,L.is_land_uint8,lon,lat,'cubic');
elseif  check_value == 2
    tf = 0;
end
output=tf;
end
   

Thank you for your time reading my concern

Update 1: Thanks Walter, I just updated my checkcheck.mat

Error message is as below:

>> dummy_run_check_island
Undefined function or variable 'check_value'.

Error in check_island (line 188)
if      check_value == 1

Error in dummy_run_check_island (line 6)
    tf_a(i)=check_island(lon,lat);

[Walter Roberson]

You do not provide us with your .mat file, and you do not show us which variable is undefined.

I predict that it is check_value . With your checks for all(), and with the elseif() without a final else(), it is not certain that check_value will always be assigned to.

[Trung Ngo]

Hi Walter sorry for being unclear, I just update the error message as well as my input file

Answer 1

[Walter Roberson]

K>> [min(lon),max(lon)]

ans =

58.1591322164013 166.237919627731

Now compare to

elseif all(lon>30.0091674417288 & lon <=60.0091673933202) 

Some lon are in that range, but not all of them are, so the elseif is false.

elseif all(lon>60.0091673933202 & lon <=90.0091673933202) 
    

Some lon are in that range, but not all of them are, so the elseif is false.

None of the other ranges are applicable.

It is not clear what result you intend in this case.

It is possible that you should be iterating over all of the ranges, and at each point, creating a mask of which values are in the lon range, and interpolating on those values, putting the results together into a whole array.

Or perhaps it would make sense to just put all of the *_size.mat data into a single array and then interpolate based upon that.

[Trung Ngo]

Hi Walter,

Because each loading matrix has a size of 2GB, hence I just want to load them each by each to compare the running time with loading them all at once. By doing that, I want to see which element of lat and lon fall into the loading matrix and conduct the interpolation method. If all is not a good idea for using it, should I remove them and just use

elseif lon>-29.9908326066798 & lon <=0.00916736910585314

for multiple condition if ?

Answer 2

[chrisw23]

The check_value variable will not be initialized and if there's no condition met the error occurs.

Initialize check_value at function start and evaluate why no if-condition is met for the given arguments.

Hope it helps

[Trung Ngo]

Would you recommend declaring variable by using persistent

function [output] = check_island(lon,lat)

persistent check_value;

if all(lon>=-180.009166666889 & lon <=-149.99083260668) 
    if all(lat<=60.0091668606037 & lat >= 29.9908328003949)
        L = load('110_size.mat');
        check_value = 1;
    elseif all(lat<29.9908328003949 & lat >= -0.00916669110301882)
        L = load('210_size.mat');
        check_value = 1;
    elseif all(lat<-0.00916669110301882 & lat >= -30.009166691103)
        L = load('310_size.mat');
        check_value = 1;
    elseif all(lat<-30.009166691103 & lat >= -60.0091670543188)
        L = load('410_size.mat');
        check_value = 1;
    end
    
...
        

[Walter Roberson]

No on the persistent. Just

check_value = 2;

in the place that you have persistent.

[Trung Ngo]

Thanks all for your help

Answer 3

[Trung Ngo]

Fix it by

clearvars;
tic
load('checkcheck.mat');
for i=1:length(lat)
    tf_a(i)=check_island(lon(i),lat(i));
end
wtime = toc;
fprintf ( 1, 'Program took %f seconds to run.\n', wtime );
 %}