What those letters means?

djevazi

Sometimes I got numeric values with letters, what those letters means?

kfrajer

That is scientific notation:
http://stackoverflow.com/questions/16098046/how-to-print-double-value-without-scientific-notation-using-java

It is another way to represent double/float. In Mathematics, you will say 3.0517578 * 10^(-5) for example. In fixed notation, you will write it as 0.000030517578. As you see, it is a very small number for most people. However, looks are deceiving, as for some people that number is still big. For example, plank constant in physics is in the order of 10^(-34).

keep in mind when you do calculations, or apply rotations and translations or when working with angles, you can get rounding errors so sometimes when you are expecting zero in a calculation, you could get numbers in the order of 10^(-7) for example. It could be a problem for certain codes.

Notice you can also do this for big numbers. The speed of light is 3E8 m/s so indeed, very fast.

Kf

djevazi

thanks for answer!