%Martin Kennelly
%class on 2-5-07
%today: Switches, formatted output, reading into very basic files.
%Switches works in place of if's, ifelses, if your data range for the decision is a finite set.
%Let's suppose we have, x=input('entre your value')%if (x==3), disp('hello')
%elseif (x==2), disp('thanks')
%elseif (x==1), disp('goodbye')
%does not work for a switch as x>2, x>1, x>3 because this is not a finite set
%lets do an example
x=input('enter value')
switch(x)
    case 1
    disp('hello')
    case 2
        disp ('thanks')
end
%now lets do a problem that takes in one unit as an input, and produces another
%unit. we're going to go from english to metric.
x=input('enter the number ')
y=input('enter the type of unit that you want to convert from ')
%we have never done an ifelse with strings, but we will now, allowing an
%input of in, ft, yd, or mi
switch(y)
    case'in'
        disp('you have ')
        x*25.4
        disp('mm')
        %with a switch, it ends up using string compare behind the scenes
    case 'ft'
        disp('you have ')
        x*.305
        disp('m')
        %now lets do formateed output
        %[%d - integer], [%e - scientific]
        fprintf(format, data)
        fprintf [%d - integer], [%e - scientific]
        %basically, we could have done this exact thing with ifelse, but it
        %would have been a lot more time consuming, and not nearly as neat
        %we could also do nested cases, which means that inside of out case
        %we could put a switch.
        %load filename, and it puts it into a matrix.
        %needs to have the same number of integers in it. ex. a 3 by 3
        %matrix.  First index is for the row, and the second index is for
        %the column.
        %if you want to save something in a format so that it can vbe rad
        %by something other thatn matlab, save it, and place,'-ascii' at
        %the end, and without quotes.
        x=input('enter the number ')
y=input('enter the type of unit that you want to convert from ')
switch(y)
    case'in'
        fprintf('you have %f mm\n',x*25.4')
        
    case 'ft'
        fprintf('you have %f meters\n',x*0.305')
end

x=input('enter the number ')
y=input('enter the type of unit that you want to convert from ')
switch(y)
    case'in'
        fprintf('Your %f inches is %f millimeters.\n',x,x*25.4)
        
    case 'ft'
        fprintf('Your %f feet is %f meters\n',x,x*0.305)
end