Major differences between MATLAB and C++

• Arrays

  • index using () instead of []
  • first index is 1 instead of 0
  • Example:
    • to get the first element of an array myPeaks:
      • MATLAB: myPeaks(1)
      • C++: myPeaks[0]

• For loops

  • To make a for loop, MATLAB has a shorthand when you know you are increasing by 1 each time.
  • Example, iterate over all elements of a four element array.
  • MATLAB: for j = 1:4
  • C++: for (int j = 0; j < 4; j++)

• Checking for not equals

  • MATLAB: a ~= b
  • C++: a != b

• Instead of brackets for if, while, and for loops, etc. , MATLAB uses end

  • Example:

    • MATLAB:

      if (a > b)
      % do something
      end
      

    • C++:

      if (a > b){
      // do something
      }
      

• Functions in MATLAB have slightly different formatting, and don’t require variable types

  • Example:

    • MATLAB:

      function heartRate = ihr(t1, t2)
      	heartRate = 1/(t2 - t1)*60;
      end
      

    • C++

      float heartRate(float t1, float t2){
      	return 1/(t2 - t1)*60;
      }
      

• In MATLAB, use elseif instead of else if in C++

  • Example:

    • MATLAB:

      if (a > b)
      % do something
      
      elseif (b > a)
      % do something else
      
      else
      % do yet another thing
      
      end
      

    • C++

      if (a > b) {
      // do something
      
      }
      else if (b > a) {
      // do something else
      
      }
      else {
      // do yet another thing
      
      }
      

MATLAB Tips

• MATLAB has an interpreter like python, so you can test your commands without having to compile your code
  • You can check your variables in the side workspace window
  • You can step through your code using the debugger and run it in sections
• Review my code for examples about how to plot and update figures
  • hold on and hold off control whether new plots are added to an existing figure or the figure is overwritten
• MATLAB handles variable types more intelligently than C++, so you don’t need to think too much about them so long as you are operating on values of similar types
• Make a comment with %
• You can output the result of a line by leaving off the closing ;
  • Example: IHR = ihr(t1, t2) will print IHR
• Check out this site for a method to get the full MATLAB waveform from a figure.