How do I access an element in an answer array directly?
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Kishore
on 24 Apr 2025 at 12:32
Commented: Stephen23
on 28 Apr 2025 at 19:55
I have a variable named snsr_type as defined below. I want extract just "Diff" and store it in snsr_type variable. I have to do this in 2 steps.
snsr_name = "Diff sensor A1";
snsr_type = split(snsr_name,' ');
snsr_type = snsr_type(1);
If I combine those last 2 lines like this, it errors out saying "Error: Invalid array indexing.". I've also tried wrapping the first part in () like (split(snsr_name,' '))(1). This also doesn't work.
snsr_type = split(snsr_name,' ')(1);
Is there any way of doing this simply in a single line? Or do I have to do this in 2 lines?
6 Comments
Image Analyst
on 26 Apr 2025 at 13:50
snsr_name = "Diff sensor A1";
snsr_type = extractBefore(snsr_name,' ') % Get first word, which is the sensor type
Accepted Answer
Image Analyst
on 24 Apr 2025 at 12:42
Evidently you need to do it in two steps. A bonus though is that the two step method is much more readable and understandable. I think the single line way would be more confusing - a head scratcher for most people.
More Answers (1)
Walter Roberson
on 28 Apr 2025 at 17:25
Two approaches:
First = @(V) V(1);
snsr_name = "Diff sensor A1";
snsr_type1 = First(split(snsr_name,' '))
snsr_type2 = struct('Data', split(snsr_name,' ')).Data(1)
2 Comments
Steven Lord
on 28 Apr 2025 at 19:48
A third (somewhat complicated) way:
snsr_name = "Diff sensor A1";
y = subsref(split(snsr_name, ' '), substruct('()', {1}))
Stephen23
on 28 Apr 2025 at 19:55
The simplest approach is likely to be faster in many situations:
timeit(@f0)
timeit(@f1)
timeit(@f2)
timeit(@f3)
function f0()
snsr_name = "Diff sensor A1";
snsr_type = split(snsr_name,' ');
snsr_type = snsr_type(1);
end
function f1()
First = @(V) V(1);
snsr_name = "Diff sensor A1";
snsr_type = First(split(snsr_name,' '));
end
function f2()
snsr_name = "Diff sensor A1";
snsr_type = struct('Data', split(snsr_name,' ')).Data(1);
end
function f3()
snsr_name = "Diff sensor A1";
snsr_type = subsref(split(snsr_name, ' '), substruct('()', {1}));
end
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