How to Convert data from HEX codes to Numeric

Hello, how can I convert data given in HEX codes to decimal.

1. Read complete file as it is
2. Output: Add a second column with values in Numeric.

Answer 1

[Voss]

format long g
T = readtable('hex codes example.xlsx')

Warning: Column headers from the file were modified to make them valid MATLAB identifiers before creating variable names for the table. The original column headers are saved in the VariableDescriptions property.
Set 'VariableNamingRule' to 'preserve' to use the original column headers as table variable names.

T = 19×1 table
             HexCodes          
    ___________________________

    {'FA 80 3E 11 01 04 00 00'}
    {'00 81 FF FF'            }
    {'FA 80 3E 11 01 04 00 00'}
    {'00 81 FF FF'            }
    {'FA 80 3E 11 01 04 00 00'}
    {'00 81 FF FF'            }
    {'FA 80 3E 11 01 04 00 00'}
    {'00 81 FF FF'            }
    {'FA 80 3E 11 01 04 00 00'}
    {'00 81 FF FF'            }
    {'FA 80 3E 11 01 04 00 00'}
    {'00 81 FF FF'            }
    {'00 FC'                  }
    {'FA 80 3E 11 01 04 00 00'}
    {'00 81 FF FF'            }
    {'FA 80 3E 11 01 04 00 00'}

T.DecCodes = hex2dec(strrep(T.HexCodes,' ',''))

Warning: Hexadecimal numbers representing integers greater than or equal to flintmax might not be represented exactly as double-precision floating-point values.

T = 19×2 table
             HexCodes                    DecCodes      
    ___________________________    ____________________

    {'FA 80 3E 11 01 04 00 00'}    1.80504955492534e+19
    {'00 81 FF FF'            }                 8519679
    {'FA 80 3E 11 01 04 00 00'}    1.80504955492534e+19
    {'00 81 FF FF'            }                 8519679
    {'FA 80 3E 11 01 04 00 00'}    1.80504955492534e+19
    {'00 81 FF FF'            }                 8519679
    {'FA 80 3E 11 01 04 00 00'}    1.80504955492534e+19
    {'00 81 FF FF'            }                 8519679
    {'FA 80 3E 11 01 04 00 00'}    1.80504955492534e+19
    {'00 81 FF FF'            }                 8519679
    {'FA 80 3E 11 01 04 00 00'}    1.80504955492534e+19
    {'00 81 FF FF'            }                 8519679
    {'00 FC'                  }                     252
    {'FA 80 3E 11 01 04 00 00'}    1.80504955492534e+19
    {'00 81 FF FF'            }                 8519679
    {'FA 80 3E 11 01 04 00 00'}    1.80504955492534e+19

writetable(T,'hex and dec codes example.xlsx')

Answer 2

[Steven Lord]

Do you mean you have the hex representation of a double precision number and want to convert it into the corresponding double? See the num2hex and hex2num functions.

Or are you trying to convert integer values? In that case see the dec2hex and hex2dec functions.

[Walter Roberson]

hex2num() can only handle double precision . You need other approaches for single precision.

But they are unlikely to be single precision or double precision.

format long g

H2=[0xfa 0x80 0x3e 0x11 01 04 00 00]

H2 = 1×8

250 128 62 17 1 4 0 0

typecast(H2, 'double')

ans = 
      2.1751886233388e-311

swapbytes(ans)

ans = 
    -1.17933560861813e+282

typecast(H2, 'single')

ans = 1×2

1.0e+00 * 1.50281e-28 1.436331e-42

swapbytes(ans)

ans = 1×2

1.0e+00 * -3.329364e+35 2.424457e-38