HOW DO I DO THAT IN MATLAB SERIES?

In this series, I am answering questions that students have asked me about MATLAB.

TOPIC
SUMMARY
INTRODUCTION
INPUTS
DISPLAYING INPUTS
CODE and DISPLAYING OUTPUT

TOPIC

How do I write program that calculates the BMI of a person and tells him if he is healthy or not and also recommends his healthy weight

SUMMARY

Language : Matlab 2010a; Authors : Autar Kaw and Sri Harsha Garapati; Mfile available at Last Revised : January 23, 2012; Abstract: This program shows you how to tell a person if he is healthy or not basing on his BMI found using his weight and height and also gives the target recommended healthy weight to a person

clc
clear all

INTRODUCTION

disp('ABSTRACT')
disp('   This program shows you how to tell a person if he is healthy or')
disp('   not basing on his BMI found using his weight and height and ')
disp('   also gives the target recommended healthy weight to a person')
disp(' ')
disp('AUTHOR')
disp('   Autar Kaw and Sri Harsha Garapati of http://autarkaw.wordpress.com')
disp(' ')
disp('MFILE SOURCE')
disp('   http://numericalmethods.eng.usf.edu/blog/bmi_program_example4_ch19_blog.m')
disp(' ')
disp('LAST REVISED')
disp('   February 13, 2012')
disp(' ')

ABSTRACT
   This program shows you how to tell a person if he is healthy or
   not basing on his BMI found using his weight and height and 
   also gives the target recommended healthy weight to a person
 
AUTHOR
   Autar Kaw and Sri Harsha Garapati of http://autarkaw.wordpress.com
 
MFILE SOURCE
   http://numericalmethods.eng.usf.edu/blog/bmi_program_example4_ch19_blog.m
 
LAST REVISED
   February 13, 2012

INPUTS

% Weight of the person in pounds
w  =180;
% Height of the person in inches
h  =72;

DISPLAYING INPUTS

disp('  ')
disp('INPUTS')

% Printing the input weight
fprintf('The weight of the person is %g lbs\n',w)
% Printing the input height
fprintf('The weight of the person is %g inches \n',h)

  
INPUTS
The weight of the person is 180 lbs
The weight of the person is 72 inches

CODE and DISPLAYING OUTPUT

% calculating BMI from the formula
bmi=(w/h^2)*703;
% rounding BMI value to the nearest integer
bmi=round(bmi);


disp('  ')
disp('OUTPUTS')
fprintf('  Your BMI is %g\n',bmi)

% Part a)
disp(' ')
disp('Part a)')
% Using if-else-end statement to check if the person if helathy or not
% if BMI is greater than 25 or BMI or less than 19 person is not-healthy
if bmi>25 | bmi<19
    disp('  This is an unhealthy BMI')
else % if he is not not-healthy then he is healthy
    disp('  This is a healthy BMI')
end

% Part b)
disp(' ')
disp('Part b)')
% Using if-end statement to check if BMI is less than 19
if bmi<19
    flag=0;
end
% Using if-end statement to check if BMI is between 19 and 25
if bmi<=25 & bmi>=19
    flag=1;
end
% Using if-end statement to check if BMI is between 25 and 30
if bmi>25 & bmi<=30
    flag=2;
end
% Using if-end statement to check if BMI is greater than 30
if bmi>30
    flag=3;
end
% Printing the value of flag variable
fprintf('  The value of flag variable is %g\n',flag)

% Part c)
disp(' ')
disp('Part c)')
% Using the value of flag to determine the category and calculate the
% target weight of the person
if flag==0
    disp('  underweight')
    tw=ceil((19*h^2)/703);
    fprintf('  Your target weight is %g\n',tw)
end
if flag==1
    disp('  healthy')
    disp('  maintain your weight')
end
if flag==2
    disp('  overweight')
    tw=floor((25*h^2)/703);
    fprintf('  Your target weight is %g\n',tw)
end
if flag==3
    disp('  obese')
    tw=floor((25*h^2)/703);
    fprintf('  Your target weight is %g\n',tw)
end

  
OUTPUTS
  Your BMI is 24
 
Part a)
  This is a healthy BMI
 
Part b)
  The value of flag variable is 1
 
Part c)
  healthy
  maintain your weight