Entering a vector in a function with if else statement

Hi Matlab community.

I made this function that should sort out data that differs more than +/- 20 % giving it "NaN" if it does. If the previous measurement varied more than 20 % it should should not do so, which i tried with the command: "(sorted_data(i-1)==NaN) && (i>1)" but when I use the debugger it does not enter this statement even though it is true. How come it won't enter this? Thanks for the help!

Kind Regards

function sorted_data=sort_for_outliers(data)
sorted_data=zeros(length(data),1);

for i=1:length(data)
    if i==1
        sorted_data(i)=[data(i)];

      elseif (sorted_data(i-1)==NaN) && (i>1)
          sorted_data(i)=[data(i)];

      elseif data(i)>1.20.*data(i-1)
          sorted_data(i)=[NaN];

      elseif data(i)<0.80.*data(i-1)
          sorted_data(i)=[NaN];

      else
          sorted_data(i)=[data(i)];
      end
  end
  end

[Torsten]

At the beginning of your function, you set "sorted_data" to zero. Thus sorted_data(i-1) will not be NaN.

Best wishes

Torsten.

Answer 1

[KL]

I'm afraid your usage of sorted_data(i-1)==NaN would always return false. The right way to find if a value is nan is to use isnan

link: https://www.mathworks.com/help/matlab/ref/isnan.html

P.S: It's always good to pay attention to the warnings on the right hand vertical bar on your editor window.

[Ida Lunde Hygum]

Hi! I tried this and it worked, thank you!

[KL]

You're welcome!