Error shows Not enough input arguments

Hello, I got one question and it keeps showing Not enought input arguments as it's error code, and cannot get a proper answer from it.

The questions is to create a logic array with true for any location where the runner is on the Red Team (R) with a running time less than 10.

The Function I wrote is :

function qualifyingIndex=FindQualify(rTeams, rTimes)
FindQualifyLocs=[(rTeams=='G'),(rTimes<10)];
qualifyingIndex=FindQualify.*FindQualifyLocs;
end

and the code to call my function is :

FindQualify(['R','B','R'],[10.1,8,11])

Answer 1

[Image Analyst]

Try this:

qualifyingIndex = (rTeams == 'R') & (rTimes < 10);

Full Demo:

rTeams = ['R','B','R'];
rTimes = [10.1,8,11];
logicalVector = FindQualify(rTeams, rTimes)
if all(~logicalVector)
	fprintf('No member of team R had a time less than 10.\n');
else
	% List them all
	for k = find(logicalVector)
		fprintf('Racer #%d on team R had a time of %.1f.\n', k, rTimes(k));
	end
end

rTeams = ['R','B','R'];
rTimes = [7.1,8,9.4];
logicalVector = FindQualify(rTeams, rTimes)
if all(~logicalVector)
	fprintf('No member of team R had a time less than 10.\n');
else
	% List them all
	for k = find(logicalVector)
		fprintf('Racer #%d on team R had a time of %.1f.\n', k, rTimes(k));
	end
end


function qualifyingIndex = FindQualify(rTeams, rTimes)
% Get a logical vector where the team = R and the time is less than 10.
qualifyingIndex = (rTeams == 'R') & (rTimes < 10);
end

For the two cases, you'll see:

logicalVector =

1×3 logical array

0 0 0

No member of team R had a time less than 10.

logicalVector =

1×3 logical array

1 0 1

Racer #1 on team R had a time of 7.1.

Racer #3 on team R had a time of 9.4.

[Ruoming Xu]

Thanks! I have already solve this question! The code I'm using:

function qualifyingIndex=FindQualify(rTeams, rTimes)

FindQualifyLocs=(rTeams=='R')&(rTimes<10);

qualifyingIndex=1.*FindQualifyLocs;

end

[Image Analyst]

Yeah, that's totally unnecessary to make that temporary variable, FindQualifyLocs.

FindQualifyLocs is already a logical variable so you're done at that point. The subsequent line where you multiply it by one actually turns it into a double, not a logical like you said you wanted. So that's wrong. Remember you said you wanted "to create a logic array" -- well you created a double, not a logical.

The correct way would be like I showed - in a single line. So it would be

function qualifyingIndex = FindQualify(rTeams, rTimes)
% Get a logical vector where the team = R and the time is less than 10.
qualifyingIndex = (rTeams == 'R') & (rTimes < 10);
end

Answer 2

[Walter Roberson]

qualifyingIndex=FindQualify.*FindQualifyLocs;

Notice in that line you have FindQualify, which is the name of the function that you are defining. That is a request to invoke that same function recursively, but this time passing in no arguments.

Unfortunately there is no documentation as to what the function is intended to do, so I cannot suggest a repair.

[Ruoming Xu]

Hi, thanks for your reply! I might typed wrong about the function, the rTeams should be rTeams=='B', but not 'G'. The function suppose to give a return like [0,1,0], since for the second one, it's both rTeams=='B', and rTimes<10.

[Walter Roberson]

[(rTeams=='B'),(rTimes<10)]

rTeams is a vector of length 3. rTimes is a vector of length 3. When you put the two vectors together with [] you get a vector of length 6.

You then try to multiply that vector of length 6 by... something. You are expecting a vector of length 3 as the result.

In order for multiplication of 1 x 6 vector to give a 1 x 3 result, you would need to be using

A is some 3 x 6 array
result = (A * FindQualifyLocs.').'

where A is some 3 x 6 array. Using * between a 3 x 6 and a (1 x 6 transposed to be 6 x 1) would give 3 x 1, and you would transpose that to get a 1 x 3.

But what should that array A be? I do not know.

I would suggest to you that [(rTeams=='B'),(rTimes<10)] is the wrong thing to compute. https://www.mathworks.com/help/matlab/ref/and.html