Exponent mantissa form of real numbers

Hi,

I'm supposed to convert the following real numbers into exponent mantissa form:

a = 789.34

b = 0.0001

c = 400000000000

My first question is: what does exponent mantissa form mean? I've read something about binary online but I doubt that that's what we're supposed to do in this exercise.

My second question is how do I convert the numbers above into exponent mantissa form using matlab?

Any help is greatly appreciated!

Many thanks,

Dobs

Answer 1

[James Tursa]

Without seeing the actual wording of the assignment, I would assume this simply means "floating point notation". E.g.,

123.456 can be written 1.23456 x 10^2 or 1.23456e2

.0123456 can be written 1.23456 x 10^-2 or 1.23456e-2

You can use lowercase e or uppercase E for the exponent. What is the actual wording of the assignment?

[Dobs]

It just says "Write the following real numbers in exponent-mantissa form" and it's an introduction to matlab class, in case that helps.

So how do I get matlab to write 123.456 as 1.23456x10^2 ?

[Walter Roberson]

See fprintf %e format

[Dobs]

Unfortunately this doesn't seem to work, it just says "not enough input arguments" :/

[Jan]

Walter's suggestion to "see" means:

doc fprintf
% Search for the %e format there

and not copy&paste "fprintf %e".

[James Tursa]

Please show us what you tried. We can't guess what you did wrong. E.g., to use fprintf:

x = 123.456;
fprintf('%e \n',x);

The %e is the exponential notation format to use to print x, and the \n is a newline so the curser will move to the next line after printing x.

[Steven Lord]

The log2 function may also be of use.