Read the e-notation part.

"format short" or "format long". See also your Preferences -> Command Window Preferences, as the default can be set there.

You may wish to give the command format short g or format long g

It is scientific notation, where e is shorthand for *10^.

You can change the output type in the console using the format command. For example . . .

>> x = 1.123456e5

x =

   1.1235e+05

>> format long
>> x

x =

     1.123456000000000e+05

>> format longG
>> x

x =

                  112345.6

>> format hex
>> x

x =

   40fb6d999999999a

Hi Christian, Try this: title(sprintf('Surface Ions per nm^2: %0.2f x 10^%i', 10^mod(log10(surfaceIons),1),floor(log10(surfaceIons))))

It's 9.4817 times 10 to the 3rd power, 9.4817 * 10^03 = 9481.7.

Use the exponential function exp(y) to compute e^y. For example:  x = 0.2; Result = (x^2)*exp(4) Result = 2.1839

The log function does exactly what you want. log(14 - y) If you want a base 10 log, you use log10. There is also a log2 function, which gives a base 2 log. Other bases are achieved using the simple relation log(X)/log(b) produces a log to the base b. You could write a function for it as: logb = @(X,b) log(X)/log(b); logb(9,3) ans = 2 which is as expected. Finally, there is the reallog function, which also does the natural log, but it produces an error when the log would have been a complex number. log(-2) ans = 0.693147180559945 + 3.14159265358979i reallog(-2) Error using reallog Reallog produced complex result. But for the more normal case, reallog does the same thing as log. log(2) ans = 0.693147180559945 reallog(2) ans = 0.693147180559945

floating point maths is not exact. There are numerous places on the web where you can read up about this. It isn't specific to Matlab, but as soon as you start doing maths on floating point numbers you start to get very small inaccuracies. -1.694065894508601e-21 is a tiny number which is generally considered to be less than the tolerance required for two numbers to be considered equal since, with floating point maths equality almost always must be done within a tolerance. Never rely on absolute equality tests for floating point data unless you know for sure where the values have come from and that they are, for example, integer valued - e.g. everything in Matlab is a double by default, even when you assign integer values so you can obviously do equality amongst these, just not the results of floating point maths.

If you are referring to the constant "e" (2.718....), then use exp(x*t)

Hi, there is no type in format that generally tells MATLAB to use such a format. Nevertheless you can always use sprintf to make a string in the format you like, in this case it would be sprintf('%f', diff) ans = 0.000400 Titus