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<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN
style="FONT-SIZE: 12pt; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: Calibri"><FONT
face=Calibri>Hello Freddie, and NeXus developers<o:p></o:p></FONT></SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Times New Roman','serif'; FONT-SIZE: 12pt; mso-fareast-font-family: 'Times New Roman'"><o:p> </o:p></SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN
style="FONT-SIZE: 12pt; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: Calibri"><FONT
face=Calibri>In the development of HisTool ( a program we have at SNS to read
raw event files and save it as a NeXus file) we implemented a feature that
allows to read the DAS event file and simultaneously write some datasets to the
NeXus file (that is, without the need to read all the DAS event file to
memory).<o:p></o:p></FONT></SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN
style="FONT-SIZE: 12pt; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: Calibri"><FONT
face=Calibri>This is done by creating the NeXus datasets as extendable (we use
HDF5).<o:p></o:p></FONT></SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN
style="FONT-SIZE: 12pt; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: Calibri"><FONT
face=Calibri>For one of the datasets being build(“event_index”) we have to
either at end <o:p></o:p></FONT></SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Times New Roman','serif'; FONT-SIZE: 12pt; mso-fareast-font-family: 'Times New Roman'"><o:p> </o:p></SPAN></P>
<P style="LINE-HEIGHT: normal; TEXT-INDENT: -0.25in; MARGIN: 0in 0in 0pt 0.5in"
class=MsoNormal><SPAN
style="FONT-SIZE: 12pt; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: Calibri"><FONT
face=Calibri>1)</FONT></SPAN><SPAN
style="FONT-FAMILY: 'Times New Roman','serif'; FONT-SIZE: 7pt; mso-fareast-font-family: 'Times New Roman'">
</SPAN><SPAN
style="FONT-SIZE: 12pt; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: Calibri"><FONT
face=Calibri>extend the dataset dimension</FONT></SPAN></P>
<P style="LINE-HEIGHT: normal; TEXT-INDENT: -0.25in; MARGIN: 0in 0in 10pt 0.5in"
class=MsoNormal><SPAN
style="FONT-SIZE: 12pt; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: Calibri"><FONT
face=Calibri>2)</FONT></SPAN><SPAN
style="FONT-FAMILY: 'Times New Roman','serif'; FONT-SIZE: 7pt; mso-fareast-font-family: 'Times New Roman'">
</SPAN><SPAN
style="FONT-SIZE: 12pt; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: Calibri"><FONT
face=Calibri>reduce the dataset dimension</FONT></SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN
style="FONT-SIZE: 12pt; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: Calibri"><FONT
face=Calibri>Problem is for 2) above NeXus does not provide a function to do
that, so we had to do it calling the HDF5 API
directly.<o:p></o:p></FONT></SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes">We
discussed this and thought that it woudld desirable that NeXus would have such a
function.<o:p></o:p></SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes">There
are 2 ways to implement this in NeXus<o:p></o:p></SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes"><o:p> </o:p></SPAN></P>
<P style="LINE-HEIGHT: normal; TEXT-INDENT: -0.25in; MARGIN: 0in 0in 0pt 0.5in"
class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Droid Sans Mono'; mso-bidi-font-size: 11.0pt">1)</SPAN><SPAN
style="FONT-FAMILY: 'Times New Roman','serif'; FONT-SIZE: 7pt; mso-fareast-font-family: 'Droid Sans Mono'">
</SPAN><SPAN
style="FONT-SIZE: 12pt; mso-ascii-font-family: Calibri; mso-fareast-font-family: 'Times New Roman'; mso-hansi-font-family: Calibri; mso-bidi-font-family: Calibri"><FONT
face=Calibri>In the function </FONT></SPAN><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; BACKGROUND: yellow; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes; mso-highlight: yellow">NX5putslab</SPAN><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes">
replace the call to </SPAN><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'"><o:p></o:p></SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt 0.5in" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; BACKGROUND: yellow; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes; mso-highlight: yellow">H5Dextend</SPAN><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes"><o:p></o:p></SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt 0.5in" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes">With<o:p></o:p></SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt 0.5in" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; BACKGROUND: yellow; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes; mso-highlight: yellow">H5Dset_extent</SPAN><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes"><o:p></o:p></SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt 0.5in" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes"><o:p> </o:p></SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt 0.5in" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes">The
second HDF5 function (<SPAN
style="BACKGROUND: yellow; mso-highlight: yellow">H5Dset_extent</SPAN>) is like
<SPAN style="BACKGROUND: yellow; mso-highlight: yellow">H5Dexten</SPAN>d but
allows to reduce a dimension as well as increase (<SPAN
style="BACKGROUND: yellow; mso-highlight: yellow">H5Dexten</SPAN>d only allows
increase)</SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt 0.5in" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes"></SPAN> </P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt 0.5in" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes">It
also happens that <SPAN
style="BACKGROUND: yellow; mso-highlight: yellow">H5Dexten</SPAN>d is going to
be deprecated (for <SPAN
style="BACKGROUND: yellow; mso-highlight: yellow">H5Dset_extent
)</SPAN></SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt 0.5in" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes"></SPAN> </P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt 0.5in" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes"></SPAN> </P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt 0.5in" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes">This
URL describes both functions</SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt 0.5in" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes"></SPAN> </P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt 0.5in" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes"><A
href="http://www.hdfgroup.org/HDF5/doc/RM/RM_H5D.html">http://www.hdfgroup.org/HDF5/doc/RM/RM_H5D.html</A></SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt 0.5in" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes"><FONT
face=Arial></FONT></SPAN> </P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt 0.5in" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes"><FONT
face=Arial></FONT></SPAN> </P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt 0.5in" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes"><o:p></o:p></SPAN> </P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 0pt 0.5in" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes"><o:p> </o:p></SPAN></P>
<P style="LINE-HEIGHT: normal; TEXT-INDENT: -0.25in; MARGIN: 0in 0in 10pt 0.5in"
class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Droid Sans Mono'; mso-no-proof: yes">2)</SPAN><SPAN
style="FONT-FAMILY: 'Times New Roman','serif'; FONT-SIZE: 7pt; mso-fareast-font-family: 'Droid Sans Mono'; mso-no-proof: yes">
</SPAN><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes">Do
a new NeXus function (for example <SPAN
style="BACKGROUND: yellow; mso-highlight: yellow">NX5putslab</SPAN>ext) that
would call <SPAN
style="BACKGROUND: yellow; mso-highlight: yellow">H5Dset_extent</SPAN><o:p></o:p></SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes"><o:p> </o:p></SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes">Let
us know what would be the best way to deal with this.<o:p></o:p></SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes">Regards<o:p></o:p></SPAN></P>
<P style="LINE-HEIGHT: normal; MARGIN: 0in 0in 10pt" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Droid Sans Mono'; FONT-SIZE: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-no-proof: yes">Pedro<o:p></o:p></SPAN></P>
<P style="MARGIN: 0in 0in 10pt" class=MsoNormal><o:p><FONT
face=Calibri> </FONT></o:p></P></DIV><FONT size=2 face=Arial>
<DIV><BR>----------------------<BR>Pedro Vicente<BR><A
href="mailto:pedro.vicente@space-research.org">pedro.vicente@space-research.org</A><BR><A
href="http://www.space-research.org/">http://www.space-research.org/</A></DIV>
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