Section: Array Generation and Manipulations
s = num2str(X)
where s is a string (or string matrix) and X is an array.  By
default, the num2str function uses 4 digits of precision and an 
exponent if required.  If you want more digits of precision, you can 
specify the precition via the form
s = num2str(X, precision)
where precision is the number of digits to include in the string
representation.  For more control over the format of the output, you 
can also specify a format specifier (see printf for more details).
s = num2str(X, format)
where format is the specifier string.