Indexing String Structure Fields

Hi folks - I am trying to index a structure field to be able to create a counter based on the number of times that a specific USER input occurs in said field, but i am having some problems with the syntax I think so seeking some help!

My structure contains many fields of data, though i'm basically just trying to make a filter to be able to reduce this by size based on one field - Regions.

I have as follows:

ABV = (extractfield(CRD2020, 'Region'))';
Entries = size(ABV);    % Create index for filtering structure
Entries = Entries(1);

a = input('Enter REGION ABV (e.g. UK, KSA etc..): ','s');   %(Region field contains country abvs - etc. UK, USA etc...)

for j=1:1:Entries
    if CRD2020(j).Region == a
        Filter(:,j)=1;
    elseif CRD2020(j).Region ~= a
        Filter(:,j)=0;
    end
end

From here on I plan to use this filter array to reduce and concatenate the entire structure, but I keep facing an error with:

if CRD2020(j).Region == a
    
 

I thought that 'CRD2020(j).Region' would be a single value.

I have also tried:

    if cellstr(CRD2020(j).Region) == a
        

Though the '==' operator doesn't support this.

Is there any way that i can change this to be able to tell when the exact same CHARACTER entries have been input?

Thanks in advance!

C.

[Stephen23]

The basic problem is likely that you are attempting element-wise comparison of character vectors of different sizes using EQ. That won't work.

One solution is to replace this code:

if CRD2020(j).Region == a
    Filter(:,j)=1;
elseif CRD2020(j).Region ~= a
    Filter(:,j)=0;
end

with this:

if strcmp(a,CRD2020(j).Region)
    Filter(:,j)=1;
else
    Filter(:,j)=0;
end

or even better with just this:

Filter(:,j) = strcmp(a,CRD2020(j).Region);

Note that you should simplify your code by thinking in terms of arrays (not in terms of loops like some poor low-level language). For example your whole code reduces down to e.g.|:

R = extractfield(CRD2020, 'Region');
a = input('Enter REGION ABV (e.g. UK, KSA etc..): ','s');
F = strcmp(R,a);

Answer 1

[Calum]

Never mind! Solved this using a simple strcmp function - hopefully this helps anyone else with a similar problem.