Difference of consecutive float numbers in a column
<p>I have a list of floating point numbers in a file in column like this:</p>

<p>123.456</p>

<p>234.567</p>

<p>345.678</p>

<p>How can i generate an output file which is generated by subtracting the value in a line with the value just above it. For the input file above,the output generated should be:</p>

<p>123.456-123.456</p>

<p>234.567-123.456</p>

<p>345.678-234.567</p>

<p>The first value should return zero, but the other values should get subtracted with the value just above it. This is not an homework question. This is a small requirement of my bigger problem and i am stuck at this point. Help much appreciated. Thanks !! </p>
