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7.3) Forming Strings: Data Type Conversion


  • You may want to form a string which includes numerical elements. The problem is that numeric variables are not strings
  • Matlab has a range of functions that can convert numbers to strings (and the reverse). If we consider "A" to be a Matlab array (scalar, vector, matrix), then:
  • numstr convert a number to a string str=num2str(A)
    num2str(A,precision)
    num2str(A,format)
    int2str convert an integer to a string str=int2str(A)
    str2num convert a string to a number A=str2num('str')
    str2double convert a string to a double A=str2double('str')
  • The reverse (strings to numbers) can be useful when we want to extract numbers from strings. For example, the file name may contain numerical data that we want to use in our calculations (i.e., latitude and longitude values). See the batch processing example
  • [matlab]
    >> year=2014;
    >> disp(['This year is ',2014])
    This year is
    [/matlab]

    "disp" outputs ascii strings to the display. We should have done

    [matlab]
    >> disp(['This year is ', num2str(year)])
    This year is 2014
    [/matlab]