MATLAB: How do i find the smallest positive number

Question

I am making a function that finds the Pivot Element of a Tableau. However everything seems to works fine beside Line 13 [ValR,Row]=min(PivotR./tableau(2:a,b)). ValR will only be the smallest number in the given range, not just positive. min function gives the smallest number(including negative). Is there something i can use instead of min function?

function pivotElement = getPivot(tableau)
      pivotElement = 0
      pivotCol = 0
      [a,b]=size(tableau)
      FirstRow=tableau(1,1:b-1)
      [ValC,Column]= min(FirstRow)
      if(ValC< 0)
          pivotCol = Column
      end;
      pivotRow=0
      PivotR=tableau(2:a,pivotCol)
      [ValR,Row]=min(PivotR./tableau(2:a,b))
      if(ValR > 0)
          pivotRow = Row
      end;
      if ((pivotRow~=0)&&(pivotCol==0))
          pivotElement = 0
      end
      if ((pivotRow==0)&&(pivotCol~=0))
          pivotElement = 1
      end
      if ((pivotRow~=0)&&(pivotCol~=0))
          pivotElement = [pivotRow;pivotCol]
      end
  end

Answer 1

There is no built-in command for that.

function [mins, idxes] = minpositive(Array, varargin)
  Array(Array<=0) = nan;
  [mins, idxes] = min(Array, varargin{:});