<DIV>&nbsp;Sir ,<BR>&nbsp;&nbsp;<BR> I want to use<STRONG> CDIFF</STRONG> function to carry out vertical difference. But<BR>&nbsp;when I use the funtion <STRONG>CDIFF</STRONG> like:<BR><STRONG>&nbsp;'define a=diff(u,z)'<BR></STRONG>&nbsp;there occur errors like:<BR>&nbsp;&nbsp;<BR><STRONG>Operation Error:&nbsp; Error from cdiff function<BR>&nbsp;&nbsp; Error ocurred at column 1<BR>&nbsp;DEFINE error:&nbsp; Invalid expression.<BR>&nbsp;Error from CDIFF:&nbsp; Specified dimension non varying<BR></STRONG>&nbsp;Why?<BR>&nbsp;&nbsp;<BR> The function DIFF can not carry out vertical difference?<BR>&nbsp;&nbsp;<BR> Help me please!</DIV>
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<DIV>Yours,</DIV>
<DIV>Zhang<BR><BR></DIV><p>__________________________________________________<br>Do You Yahoo!?<br>Tired of spam?  Yahoo! Mail has the best spam protection around <br>http://mail.yahoo.com