reading an Excel file

From: Matthias Drescher (matthias.drescher_at_siemens.com)
Date: 03/31/04 

Date: Wed, 31 Mar 2004 10:46:38 +0200

Hi there,

I have a litte problem while reading from a Excelfile.
Im try to read a 4 byte value and convert it into an integer or floating
point value with the following criteria:

Thats what the definiton says:

An RK valie is an encoded integer or floating-point value. RK values have a
size of 4 bytes and are used to decrease the size for floating-point values.
Structure of an RK value (32-bit value),

Bit |Mask |Contents
----------------------------------------------------------------------------
----------------------
0 00000001(hex) 0 = Value not changed 1 = Value is
multiplied by 100
1 00000002(hex) 0 = Floating Point Value 1 = Signed
integer value
31-2 FFFFFFFC(hex) Encoded Value

If Bit 1 is cleared, the encoded value represents the 30 most significant
bits of an IEEE 754 floating point value (64-bit double precision). The 43
least significant bits must be set to zero. If bit 1 is set, the encoded
value represents a signed 30-bit integer value. To get the correct integer,
the encoded value has to be shifted right arithmetically by 2 bits. If bit 0
us set, the decoded value (both integer and floating-point) must be be
divided by 100 to get the final result.

So far what the definition says.

Could anybody helpme with a function that does what the definiton says ???

I tried to solve this with the following function:

<?
function double4byte()
 {
  // for testing a fixed value:
  // test float value 1
  //$val = 0x3FF00000;
  // test float value 2
  //$val = 0x3FF00001;
  // test integer value 1
  //$val = 0x004B5646;
  // test integer value 2
  $val = 0x004B5647;

  if (($val & 0x02) != 0)
  {
    echo "Integer ... ";
    $intval = $val >> 2;
    $value = doubleval($intval);

    if (($val & 0x01) != 0)
    {
        echo "multiplied by 100 ... ";
        $value /= 100;
    }
    return $value;
  }
  else
  {
   echo "floating point ... ";
   $valbits = $val & 0xfffffffc;
   $valbits = $valbits << 32;
   $value = $valbits;

   if (($val & 0x01) != 0)
   {
    echo "multiplied by 100 ... ";
    $value /= 100;
   }
   return $value;
  }
 }

 echo double4byte();

?>

I´m quite sure that it works for the integer values, but the floating point
operations are a big problem for me.
Could anybody help me please ???

Best regards Matthias