how to solve blueshift

for c = 1:7
    s = spectra(:,c);
    loglog(lambda,s,"--")
    if speed(c) <= 0
        
    end
    hold on
end

this is showing an error.plz help to solve it

[Ameer Hamza]

What is the error? Can you attach the value of variables? What is the purpose of if block?

[HARPREET KAUR]

The answer was not accepting variable s along y axis

[Bjorn Gustavsson]

For us to help you to resolve your prolem you'll have to submitt the error-message, preferably also the output from the whos command executed just before the loop.

One thing older versions of matlab never accepted is the "--" - it should be '--', i.e. single-quoutes.

[Priyanka Vyas]

for v = 1:7
    s = spectra(:,v);

    if speed(v<= 0)
        plot(lambda,s,'--')
    else
        plot(lambda,s,"LineWidth",3) 
    end
    hold on
end
hold off

This command showing error

[Priyanka Vyas]

What is wrong in above code? due to this I am not able to complete on ramp certification...

[Walter Roberson]

v is in the range 1 to 7. This is never less than or equal to 0, so speed(v<=0) is going to be empty. Testing an empty variable gives a false result. The effect is as if you had

for v = 1:7
    s = spectra(:,v);

        plot(lambda,s,"LineWidth",3) 

    hold on
end
hold off

This assumes that spectra(:,v) exists and that speed() is a variable... if speed is a function then it would have to accept a single logical parameter.