I want to input a piecewise function but getting problem in line to that "NOT ENOUGH I/P ARGUMENT"

The code that I can think of is given bellow

function y=dango(t)

if (-5<=t&t<-4)

      y=5+t;
  elseif -4<=t&t<=4
      y=1;
  elseif 4<=t&t<=5;
      y=5-t;
  else
      y=0;
  end
      t= -6:.01:6;

     for i=1:length(t)

      y(i)=dango(t(i));
     end
     plot(t,y)
     axis([-6 6 -5 5])
    *
    | how should I correct it?
Matlab version: 2011b|*

Answer 1

[Geoff Hayes]

See the resolution to http://www.mathworks.com/matlabcentral/answers/153957-not-enough-input-arguments-m-file-piecewise-function which is incredibly similar to this problem.

Answer 2

[Star Strider]

This one-line if-then-else implementation works, runs without error and seems to produce appropriate output:

dango = @(t) [(-5<=t&t<-4)*(5+t) + (-4<=t&t<=4)*1 + (4<=t&t<=5)*(5-t) + (t>5)*0];

       t= -6:.01:6;
       for i=1:length(t)
           y(i)=dango(t(i));
       end
       plot(t,y)
       axis([-6 6 -5 5])

When I plotted it, there was a ‘glitch’ at 4, but I followed (copy-pasted) your conditions exactly, so perhaps this is the result you intend. If there’s a problem, I’ll let you sort it. One problem might be that in the second and third elements, t<=4 in the second element, and 4<=t in the third element. Mayhap 4<t in the third element would remove the glitch? It did when I made the change and ran the code.

One-line if-then-else statements are really quite efficient. I now make extensive use of them for their efficiency in both coding and execution. They operate on the simple principle that if the associated logic statement evaluates to false=0, they essentially don’t evaluate, but if the associated logic statement evaluates to true=1 they do, and are reported at the output.