Using GUI Designer to convert integer inputs to exponential form (convert MHz to integer Hertz)

My orginial inputs in a .m function are in Hertz and then combined in an aray as follows:

x1 = 5700e6

x2 = 4750e6

x3 = 4950e6

x_array = [x1, x2, x3]

In Matlab Designer/GUI where the user can enter values in MHz, how do I input the values as say 5700 MHz and have it convert it to 5700e6?

This is what I have currently, but it doesn't match the orginal above:

x1 = str2double(app.EditField_x1.Value);

x1 = x1 * 10e5;

x_array = [x1, x2, x3];

The 'double' could be the issue.... Should it be str2num or something else? Then can I multiply that value to represent it as a Hertz value (to match the form 5700e06)? I can't seem to get it to match and it is affecting my output.

Thanks in advance!

[Stephen23]

"how do I input the values as say 5700 MHz and have it convert it to 5700e6?"

num = str2double('5700');
fprintf('%.30f\n', num*1e6, num*10^6, 5700e6)

5700000000.000000000000000000000000000000
5700000000.000000000000000000000000000000
5700000000.000000000000000000000000000000

[Scotty Mac]

Thanks Stephen!

Answer 1

[Walter Roberson]

If the user is expected to enter 5700 and that is to represent the same as 5700e6 would, then you should be multiplying by 1e6 instead of by 1e5.

str2double() is better than str2num() in the majority of cases.

format long g
x1 = '5700'

x1 = '5700'

x1n = str2num(x1)

x1n = 
        5700

x1d = str2double(x1)

x1d = 
        5700

x1n - x1d

ans = 
     0

x2 = '5700e6'

x2 = '5700e6'

x2n = str2num(x2)

x2n = 
                5700000000

x2d = str2double(x2)

x2d = 
                5700000000

x2n - x2d

ans = 
     0

x1d * 1e6 -  x2d

ans = 
     0

[Scotty Mac]

Thanks Walter