source: trunk/SRC/Documentation/xmldoc/wiki/FirstSteps @ 354

= First steps with SAXO =
[[PageOutline]]

    
    
    
     
  
== Before this ==

In this document, we supposed that you followed [wiki:GetSaxo Get SAXO] recommendations.

== First plots 
 ==

=== Start IDL session: @init ===

Each IDL session using SAXO must always start with:

{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
 <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">@init</strong></span></code></strong>
</pre>
}}}
''The @ is equivalent to an include. It is used to execute a set of IDL commands that will be directly executed without any compilation (as it is the case for a procedure or a function). All variables defined and used in the @
 file will still be accessible after the execution of the @
 is finished (which is not the case for procedures and functions that ends with the return instruction).''
{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
  <code class="prompt">$</code> <strong class="userinput"><code><span><strong class="command">cd</strong></span> ${HOME}/My_IDL/</code></strong>
  <code class="prompt">$</code> <strong class="userinput"><code><span><strong class="command">idl</strong></span></code></strong>
  <code class="computeroutput">IDL Version 6.0, Mac OS X (darwin ppc m32). (c) 2003, Research Systems, Inc.</code>
  <code class="computeroutput">Installation number: 35411.</code>
  <code class="computeroutput">Licensed for personal use by Jean-Philippe BOULANGER only.</code>
  <code class="computeroutput">All other use is strictly prohibited.</code>
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">@init</strong></span></code></strong>
  <code class="computeroutput">% Compiled module: KEEP_COMPATIBILITY.</code>
  <code class="computeroutput">% Compiled module: FIND.</code>
  <code class="computeroutput">% Compiled module: PATH_SEP.</code>
  <code class="computeroutput">% Compiled module: STRSPLIT.</code>
  <code class="computeroutput">% Compiled module: DEF_MYUNIQUETMPDIR.</code>
  <code class="computeroutput">We forget the compatibility with the old version</code>
  <code class="computeroutput">% Compiled module: DEMOMODE_COMPATIBILITY.</code>
  <code class="computeroutput">% Compiled module: ISADIRECTORY.</code>
  <code class="computeroutput">% Compiled module: LCT.</code>
  <code class="computeroutput">% Compiled module: RSTRPOS.</code>
  <code class="computeroutput">% Compiled module: REVERSE.</code>
  <code class="computeroutput">% Compiled module: STR_SEP.</code>
  <code class="computeroutput">% Compiled module: LOADCT.</code>
  <code class="prompt">idl&gt;</code>
</pre>
}}}

As an IDL session using SAXO must always start with :

{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
 <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">@init</strong></span></code></strong>
</pre>
}}}

, it could be convenient to define the environment variable IDL_STARTUP to {{{${HOME}/My_IDL/init.pro}}}. In that way, {{{init.pro}}} will automatically been executed when starting IDL. This can be done with the following command:
      

'''csh'''
{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen"><code class="prompt">$</code> <strong class="userinput"><code><span><strong class="command">setenv</strong></span> IDL_STARTUP ${HOME}/My_IDL/init.pro</code></strong></pre>
}}}


'''ksh'''
{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen"><code class="prompt">$</code> <strong class="userinput"><code><span><strong class="command">export</strong></span> IDL_STARTUP=${HOME}/My_IDL/init.pro</code></strong></pre>
}}}


=== Basic plots 
 ===

==== splot ====

  
    
  

{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
   <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">n = 10</strong></span></code></strong>
   <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">y = findgen(n)</strong></span></code></strong> [[Image(source:/trunk/SRC/Documentation/xmldoc/images/callouts/1.png)]]1
   <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">plot, y</strong></span></code></strong> [[Image(source:/trunk/SRC/Documentation/xmldoc/images/showfig.png)]]show result
</pre>
}}}

   
    
      {{{findgen}}} stands for '''f'''loat '''ind'''ex '''gen'''erator.

{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">print, findgen(6)</strong></span></code></strong>
  <code class="computeroutput">      0.00000      1.00000      2.00000      3.00000      4.00000      5.00000</code>
</pre>
}}}

    
  

Using IDL {{{plot}}} command is quite inconvenient to save the figure as a postscript. In addition, positioning the figure on the window/page by using {{{!p.position}}}, {{{!p.region}}} and {{{!p.multi}}} is often a nightmare. That's why we developed {{{splot}}} (like super-plot) which can be used in the same way as plot but is much more convenient to make postscript and position the figure.

{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">splot, y</strong></span></code></strong> [[Image(source:/trunk/SRC/Documentation/xmldoc/images/showfig.png)]]show result
  <code class="computeroutput">% Compiled module: SPLOT.</code>
  <code class="computeroutput">% Compiled module: REINITPLT.</code>
  <code class="computeroutput">% Compiled module: PLACEDESSIN.</code>
  <code class="computeroutput">% Compiled module: CALIBRE.</code>
  <code class="computeroutput">% Compiled module: GIVEWINDOWSIZE.</code>
  <code class="computeroutput">% Compiled module: GET_SCREEN_SIZE.</code>
  <code class="computeroutput">% Compiled module: TERMINEDESSIN.</code>
</pre>
}}}

Save the figure seen on the screen as a (real, not a screen capture) postscript in only one command.

  
    
  

{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">@ps</strong></span></code></strong>
  <code class="computeroutput">% Compiled module: GETFILE.</code>
  <code class="computeroutput">% Compiled module: PUTFILE.</code>
  <code class="computeroutput">% Compiled module: OPENPS.</code>
  <code class="computeroutput">% Compiled module: XQUESTION.</code>
  <code class="computeroutput">Name of the postscript file? (default answer is idl.ps)</code><strong class="userinput"><code>first_ps</code></strong> [[Image(source:/trunk/SRC/Documentation/xmldoc/images/callouts/1.png)]]1
  <code class="computeroutput">% Compiled module: ISAFILE.</code>
  <code class="computeroutput">% Compiled module: XNOTICE.</code>
  <code class="computeroutput">% Compiled module: CLOSEPS.</code>
  <code class="computeroutput">% Compiled module: PRINTPS.</code>
  <code class="computeroutput">% Compiled module: FILE_WHICH.</code>
  <code class="computeroutput">% Compiled module: CW_BGROUP.</code>
  <code class="computeroutput">% Compiled module: XMANAGER.</code>
</pre>
}}}

  
    
      
If needed, the name of the postscript will automatically be completed with .ps. Just hit return, if you want to use the default postscript name: {{{idl.ps}}}.
      
    
  

Check that the "first_ps.ps" file is now existing 


{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">print, file_test(psdir + 'first_ps.ps')</strong></span></code></strong>
  <code class="computeroutput">           1</code>
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">help, file_info(psdir + 'first_ps.ps'), /structure</strong></span></code></strong>
  <code class="computeroutput">** Structure FILE_INFO, 21 tags, length=64, data length=63:</code>
  <code class="computeroutput">   NAME            STRING    '/Users/sebastie/IDL/first_ps.ps'</code>
  <code class="computeroutput">   EXISTS          BYTE         1</code>
  <code class="computeroutput">   READ            BYTE         1</code>
  <code class="computeroutput">   WRITE           BYTE         1</code>
  <code class="computeroutput">   EXECUTE         BYTE         0</code>
  <code class="computeroutput">   REGULAR         BYTE         1</code>
  <code class="computeroutput">   DIRECTORY       BYTE         0</code>
  <code class="computeroutput">   BLOCK_SPECIAL   BYTE         0</code>
  <code class="computeroutput">   CHARACTER_SPECIAL</code>
  <code class="computeroutput">                   BYTE         0</code>
  <code class="computeroutput">   NAMED_PIPE      BYTE         0</code>
  <code class="computeroutput">   SETUID          BYTE         0</code>
  <code class="computeroutput">   SETGID          BYTE         0</code>
  <code class="computeroutput">   SOCKET          BYTE         0</code>
  <code class="computeroutput">   STICKY_BIT      BYTE         0</code>
  <code class="computeroutput">   SYMLINK         BYTE         0</code>
  <code class="computeroutput">   DANGLING_SYMLINK</code>
  <code class="computeroutput">                   BYTE         0</code>
  <code class="computeroutput">   MODE            LONG               420</code>
  <code class="computeroutput">   ATIME           LONG64                1122424373</code>
  <code class="computeroutput">   CTIME           LONG64                1122424373</code>
  <code class="computeroutput">   MTIME           LONG64                1122424373</code>
  <code class="computeroutput">   SIZE            LONG64                      4913</code>
</pre>
}}}
{{{splot}}} accepts the same keywords as {{{plot}}} (/ISOTROPIC, MAX_VALUE=value, MIN_VALUE=value, NSUM=value, /POLAR, THICK=value, /XLOG, /YLOG, /YNOZERO), including the graphics keywords (BACKGROUND, CHARSIZE, CHARTHICK, CLIP, COLOR, DATA, DEVICE, FONT, LINESTYLE, NOCLIP, NODATA, NOERASE, NORMAL, POSITION, PSYM, SUBTITLE, SYMSIZE, T3D, THICK, TICKLEN, TITLE, [XYZ]CHARSIZE, [XYZ]GRIDSTYLE, [XYZ]MARGIN, [XYZ]MINOR, [XYZ]RANGE, [XYZ]STYLE, [XYZ]THICK, [XYZ]TICKFORMAT, [XYZ]TICKINTERVAL, [XYZ]TICKLAYOUT, [XYZ]TICKLEN, [XYZ]TICKNAME, [XYZ]TICKS, [XYZ]TICKUNITS, [XYZ]TICKV, [XYZ]TICK_GET, [XYZ]TITLE, ZVALUE).

It can therefore be customized ''as much as you want''. See this short example:

{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">splot, y, y^2, linestyle = 2, thick = 2, title = 'y = x^2', /portrait</strong></span></code></strong> [[Image(source:/trunk/SRC/Documentation/xmldoc/images/showfig.png)]]show result
</pre>
}}}
{{{splot}}} can be used to setup the graphic environment ({{{!p}}}, {{{!x}}}, {{{!y}}}, {{{!z}}} variables) needed by procedures like {{{oplot}}}
{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">splot, y, yrange = [0, (n-1)^2], title = 'x and x^2'</strong></span></code></strong>
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">oplot, y^2, color = 50, linestyle = 2</strong></span></code></strong> [[Image(source:/trunk/SRC/Documentation/xmldoc/images/showfig.png)]]show result
</pre>
}}}

Use the keyword small to produce multi plots figures.

  
    
      
      
    
    
  

{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">splot, y, y^2, title = 'y = x^2', psym = 2, small 1 = [1, 2, 1]</strong></span></code></strong>
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">splot, findgen(360)/36., findgen(360)*2.*!dtor, /polar $</strong></span></code></strong>
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">    , small 1 = [1, 2, 2], /noerase 2</strong></span></code></strong> [[Image(source:/trunk/SRC/Documentation/xmldoc/images/showfig.png)]]show result
</pre>
}}}

  
    
      
the small keyword is a 3 elements vector which defines how we divide the page and in which case we should make the plot: [number of columns, number of rows, case number]. The case numbering is starting at 1, from top to bottom and left to right.
      
    
    
      
you must put /noerase otherwise the second plot will be done in a new window.
      
    
  

==== scontour ====

Following {{{splot}}} example, we provide {{{scontour}}} as a "super contour".

{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">z = dist(n)</strong></span></code></strong>
  <code class="computeroutput">% Compiled module: DIST.</code>
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">scontour, z</strong></span></code></strong> [[Image(source:/trunk/SRC/Documentation/xmldoc/images/showfig.png)]]show result
  <code class="computeroutput">% Compiled module: SCONTOUR.</code>
  <code class="computeroutput">% Compiled module: CHKSTRU.</code>
</pre>
}}}
{{{scontour}}} accepts the same keywords as {{{contour}}} (C_ANNOTATION=vector_of_strings, C_CHARSIZE=value, C_CHARTHICK=integer, C_COLORS=vector, C_LABELS=vector{each element 0 or 1}, C_LINESTYLE=vector, { /FILL | /CELL_FILL | C_ORIENTATION=degrees}, C_SPACING=value, C_THICK=vector, /CLOSED, /DOWNHILL, /FOLLOW, /IRREGULAR, /ISOTROPIC, LEVELS=vector, NLEVELS=integer{1 to 60}, MAX_VALUE=value, MIN_VALUE=value, /OVERPLOT, {/PATH_DATA_COORDS, PATH_FILENAME=string, PATH_INFO=variable, PATH_XY=variable}, TRIANGULATION=variable, /PATH_DOUBLE, /XLOG, /YLOG, ZAXIS={0 | 1 | 2 | 3 | 4}), including the graphics keywords (except LINESTYLE, PSYM, SYMSIZE).
      It can therefore be customized ''as much as you want''. See these short examples:
{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">scontour, z, /fill, nlevels = 15, subtitle = 'nicer contour' $</strong></span></code></strong>
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">    , xtitle = 'x index', charsize = 1.5</strong></span></code></strong> [[Image(source:/trunk/SRC/Documentation/xmldoc/images/showfig.png)]]show result
</pre>
}}}

It can be used in combination with contour to make more complex plots:

  
    
  

{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">ind = findgen(2*n)/(2.*n)</strong></span></code></strong>
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">scontour, z, levels = n*ind, c_orientation = 180*ind, c_spacing = 0.4*ind</strong></span></code></strong>
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">contour, z, /overplot, c_label = rebin([1, 0], 2, n) 1, levels = n*ind $</strong></span></code></strong>
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">    , c_charthick = 2, c_charsize = 1.5, c_colors = 250*ind</strong></span></code></strong> [[Image(source:/trunk/SRC/Documentation/xmldoc/images/showfig.png)]]show result
</pre>
}}}


  
    {{{rebin}}} is used to build an array containing an alternation of 1 and 0 in order to label one contour every two contours.

{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">print, rebin([1, 0], 2, 3)</strong></span></code></strong>
  <code class="computeroutput">       1       0</code>
  <code class="computeroutput">       1       0</code>
  <code class="computeroutput">       1       0</code>
</pre>
}}}

  

{{{scontour}}} is compatible with the positioning method associated with the small keyword. See for example the test file [../../Tests/tst_basic.pro tst_basic.pro]:

{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">tst_basic</strong></span></code></strong> [[Image(source:/trunk/SRC/Documentation/xmldoc/images/showfig.png)]]show result
</pre>
}}}

==== Quick look and explore 2D arrays: tvplus ====
{{{tvplus}}} is a enhanced version of {{{tvscl}}} and allow you to have a quick look and perform basic exploration of 2D arrays.

{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
 <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">tvplus, dist(20)</strong></span></code></strong> [[Image(source:/trunk/SRC/Documentation/xmldoc/images/showfig.png)]]show result
 <code class="computeroutput">left button  : mouse position and associated array value</code>
 <code class="computeroutput">middle button: use it twice to define a zoom box</code>
 <code class="computeroutput">right button : quit</code>
 <code class="computeroutput">(x, y) = (  5,   5), value = 7.07107</code>
 <code class="computeroutput">(x, y) = ( 12,   8), value = 11.3137</code>
 </pre>
}}}

For more informations on {{{tvplus}}}, try:

{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
 <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">xhelp, 'tvplus'</strong></span></code></strong>
</pre>
}}}

To see the source code of {{{tvplus}}}, try:

{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
 <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">xfile, 'tvplus'</strong></span></code></strong>
</pre>
}}}
New Feature

If you use an IDL 6.2 or later revision, you can simply get the help of any command by typing ?'''''command_name''''', for example:

{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
 <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">?tvplus</strong></span></code></strong>
</pre>
}}}


==== Formal quick look at 2D arrays: pltv ====
{{{pltv}}} is a mix between tvplus and plt and allow you to have formal quick look of 2D arrays.
  
{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">pltv, dist(20)</strong></span></code></strong> [[Image(source:/trunk/SRC/Documentation/xmldoc/images/showfig.png)]]show result
  </pre>
}}}

== Explore gridded data (model outputs and observations) ==

      This section briefly describes the main functionalities offered by SAXO to explore gridded data on regular or irregular grid.
    
=== Load the data grid ===

As we focus in this section on the gridded data, we must first load the grid informations before reading and plotting the data. Loading the grid independently of the data allow you to reload the grid only when it is strictly necessary and not every time you access the data. In {{{${HOME}/SAXO_DIR/Tests/}}}, we provide several examples to load a grid.
      
==== Easiest solution: load data grid (regular or not) directly from the data file ====

  Example of Levitus temperature on a regular 1x1 grid.
  
{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">@tst_initlev</strong></span></code></strong>
  <code class="computeroutput">% Compiled module: INITNCDF.</code>
  <code class="computeroutput">% Compiled module: ISAFILE.</code>
  <code class="computeroutput">% Compiled module: UNIQ.</code>
  <code class="computeroutput">% Loaded DLM: NCDF.</code>
  <code class="computeroutput">% Compiled module: COMPUTEGRID.</code>
  <code class="computeroutput">% Compiled module: DOMDEF.</code>
  <code class="computeroutput">% Compiled module: INTER.</code>
  <code class="computeroutput">% Compiled module: TRIANGULE.</code>
  <code class="computeroutput">% Compiled module: TRIANGULE_C.</code>
  <code class="computeroutput">% Compiled module: UNDEFINE.</code>
  <code class="computeroutput">% Compiled module: TESTVAR.</code>
  <code class="computeroutput">% Compiled module: DIFFERENT.</code>
  <code class="computeroutput">% Compiled module: DEFINETRI.</code>
  </pre>
}}}

  This [../../Tests/tst_initlev.pro @tst_initlev] command allows us to define:
  
 * domain dimensions, stored in {{{jpi, jpj and jpk}}}
 * points abscissa, stored in 2D array {{{}}}glamt
 * points ordinates, stored in 2D array {{{}}}gphit
 * points depths, stored in 1D array {{{}}}gdept
 * cells corners abscissa, stored in 2D array {{{}}}glamf
 * cells corners ordinates, stored in 2D array {{{}}}gphif
 * cells upper boundary depth, stored in 1D array {{{}}}gdepw
 * land-sea mask, stored in {{{tmask}}}
 * the cells size in the longitudinal direction, stored in 2D array {{{}}}e1t
 * the cells size in the latitudinal direction, stored in 2D array {{{}}}e2t
 * the cells size in the vertical direction, stored in 1D array {{{}}}e3t
 * the triangulation used to fill the land points, stored in {{{}}}triangles_list
{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">help, jpi,jpj,jpk</strong></span></code></strong>
  <code class="computeroutput">JPI (LOCAL_COORD)   LONG      =          360</code>
  <code class="computeroutput">JPJ (LOCAL_COORD)   LONG      =          180</code>
  <code class="computeroutput">JPK (LOCAL_COORD)   LONG      =           33</code>
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">help, glamt, gphit,glamf, gphif</strong></span></code></strong>
  <code class="computeroutput">GLAMT (LONGITUDES)  FLOAT     = Array[360, 180]</code>
  <code class="computeroutput">GPHIT (LATITUDES)   FLOAT     = Array[360, 180]</code>
  <code class="computeroutput">GLAMF (LONGITUDES)  FLOAT     = Array[360, 180]</code>
  <code class="computeroutput">GPHIF (LATITUDES)   FLOAT     = Array[360, 180]</code>
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">help, gdept, gdepw</strong></span></code></strong>
  <code class="computeroutput">GDEPT (VERTICAL)    FLOAT     = Array[33]</code>
  <code class="computeroutput">GDEPW (VERTICAL)    FLOAT     = Array[33]</code>
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">help, e1t, e2t, e3t</strong></span></code></strong>
  <code class="computeroutput">E1T (SCALE_FACTORS) FLOAT     = Array[360, 180]</code>
  <code class="computeroutput">E2T (SCALE_FACTORS) FLOAT     = Array[360, 180]</code>
  <code class="computeroutput">E3T (VERTICAL)      FLOAT     = Array[33]</code>
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">help, tmask</strong></span></code></strong>
  <code class="computeroutput">TMASK (MASKS)       BYTE      = Array[360, 180, 33]</code>
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">help, triangles_list</strong></span></code></strong>
  <code class="computeroutput">TRIANGLES_LIST (LIEES_A_TRIANGULE) LONG      = Array[3, 128880]</code>
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">tvplus, glamt*tmask[*,*,0]</strong></span></code></strong>
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">tvplus, gphit*tmask[*,*,0]</strong></span></code></strong>
  </pre>
}}}

  We provide other initialization methods/examples
  
 *  [../../Tests/tst_initorca2_short.pro @tst_initorca2_short] : ORCA2 example
 *  [../../Tests/tst_initorca05_short.pro @tst_initorca05_short] : ORCA05 example
 *  [../../Tests/tst_initlev_stride.pro @tst_initlev_stride] : same as @tst_initlev but we skip on point over 2 in x and y direction
 *  [../../Tests/tst_initorca2_short_stride.pro @tst_initorca2_short_stride] : ORCA2 with stride
 *  [../../Tests/tst_initorca05_short_stride.pro @tst_initorca05_short_stride] : ORCA05 with stride
 *  [../../Tests/tst_initlev_index.pro @tst_initlev_index] : in that case we load the grid using points index as axis instead of the longitude/latitude position
 *  [../../Tests/tst_initorca2_index.pro @tst_initorca2_index] : load ORCA2 as it see by the model
 *  [../../Tests/tst_initorca05_index.pro @tst_initorca05_index] : load ORCA05 as it see by the model
 *  [../../Tests/tst_initlev_index_stride.pro @tst_initlev_index_stride] : @tst_initlev_index with stride
 *  [../../Tests/tst_initorca2_index_stride.pro @tst_initorca2_index_stride] : ORCA2 in index with stride
 *  [../../Tests/tst_initorca05_index_stride.pro @tst_initorca05_index_stride] : ORCA05 in index with stride
==== Load the grid from OPA meshmask file ====

  When the grid is really irregular (its abscissa and ordinate cannot be descried by a vector), loading the grid directly from the data forces us to make an approximation when computing the grid corners position and the cells size. In that case, it can be preferable to load the grid from the meshmask file created by OPA. As OPA use a Arakawa-C discretization, loading the grid from the meshmask will also define all parameters related to the U, V and F grids (glam[uv],gphi[uv], e[12][uvf]). Note that, when using a simple grid definition from the data itself (with {{{initncdf}}} or {{{computegrid}}}), adding the keyword /FULLCGRID leads also to the definition of all U, V and F grids parameters. There is the examples to load ORCA grids from OPA meshmask.
  
 *  [../../Tests/tst_initorca2.pro @tst_initorca2] : ORCA2
 *  [../../Tests/tst_initorca05.pro @tst_initorca05] : ORCA05
 *  [../../Tests/tst_initorca2_stride.pro @tst_initorca2_stride] : ORCA2 with stride
 *  [../../Tests/tst_initorca05_stride.pro @tst_initorca05_stride] : ORCA05 with stride
 *  [../../Tests/tst_initorca2_index.pro @tst_initorca2_index] : load ORCA2 as it see by the model
 *  [../../Tests/tst_initorca05_index.pro @tst_initorca05_index] : load ORCA05 as it see by the model
 *  [../../Tests/tst_initorca2_index_stride.pro @tst_initorca2_index_stride] : ORCA2 in index with stride
 *  [../../Tests/tst_initorca05_index_stride.pro @tst_initorca05_index_stride] : ORCA05 in index with stride
=== Horizontal plots and maps ===

  A quick presentation of horizontal plots and maps is shown in [../../Tests/tst_plt.pro tst_plt]. After loading any of the grid (for example with one of the above examples). Just try:
  
{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">tst_plt</strong></span></code></strong>
  </pre>
}}}
''Beware, the command is tst_plt and not @tst_plt as tst_plt.pro is a procedure and not an include.''
  See the results with
  
 * @tst_initlev
 [figpng/tst_plt_lev_01.png show result]
 [figpng/tst_plt_lev_02.png show result]
 [figpng/tst_plt_lev_03.png show result]
 [figpng/tst_plt_lev_04.png show result]
 [figpng/tst_plt_lev_05.png show result]
 [figpng/tst_plt_lev_06.png show result]
 [figpng/tst_plt_lev_07.png show result]
 [figpng/tst_plt_lev_08.png show result]
 [figpng/tst_plt_lev_09.png show result]
 [figpng/tst_plt_lev_10.png show result]
 * @tst_initorca2
 [figpng/tst_plt_orca2_01.png show result]
 [figpng/tst_plt_orca2_02.png show result]
 [figpng/tst_plt_orca2_03.png show result]
 [figpng/tst_plt_orca2_04.png show result]
 [figpng/tst_plt_orca2_05.png show result]
 [figpng/tst_plt_orca2_06.png show result]
 [figpng/tst_plt_orca2_07.png show result]
 [figpng/tst_plt_orca2_08.png show result]
 [figpng/tst_plt_orca2_09.png show result]
 [figpng/tst_plt_orca2_10.png show result]
 * @tst_initorca05
 [figpng/tst_plt_orca05_01.png show result]
 [figpng/tst_plt_orca05_02.png show result]
 [figpng/tst_plt_orca05_03.png show result]
 [figpng/tst_plt_orca05_04.png show result]
 [figpng/tst_plt_orca05_05.png show result]
 [figpng/tst_plt_orca05_06.png show result]
 [figpng/tst_plt_orca05_07.png show result]
 [figpng/tst_plt_orca05_08.png show result]
 [figpng/tst_plt_orca05_09.png show result]
 [figpng/tst_plt_orca05_10.png show result]
 * @tst_initlev_stride
 [figpng/tst_plt_lev_stride_01.png show result]
 [figpng/tst_plt_lev_stride_02.png show result]
 [figpng/tst_plt_lev_stride_03.png show result]
 [figpng/tst_plt_lev_stride_04.png show result]
 [figpng/tst_plt_lev_stride_05.png show result]
 [figpng/tst_plt_lev_stride_06.png show result]
 [figpng/tst_plt_lev_stride_07.png show result]
 [figpng/tst_plt_lev_stride_08.png show result]
 [figpng/tst_plt_lev_stride_09.png show result]
 [figpng/tst_plt_lev_stride_10.png show result]
 * @tst_initorca2_stride
 [figpng/tst_plt_orca2_stride_01.png show result]
 [figpng/tst_plt_orca2_stride_02.png show result]
 [figpng/tst_plt_orca2_stride_03.png show result]
 [figpng/tst_plt_orca2_stride_04.png show result]
 [figpng/tst_plt_orca2_stride_05.png show result]
 [figpng/tst_plt_orca2_stride_06.png show result]
 [figpng/tst_plt_orca2_stride_07.png show result]
 [figpng/tst_plt_orca2_stride_08.png show result]
 [figpng/tst_plt_orca2_stride_09.png show result]
 [figpng/tst_plt_orca2_stride_10.png show result]
 * @tst_initorca05_stride
 [figpng/tst_plt_orca05_stride_01.png show result]
 [figpng/tst_plt_orca05_stride_02.png show result]
 [figpng/tst_plt_orca05_stride_03.png show result]
 [figpng/tst_plt_orca05_stride_04.png show result]
 [figpng/tst_plt_orca05_stride_05.png show result]
 [figpng/tst_plt_orca05_stride_06.png show result]
 [figpng/tst_plt_orca05_stride_07.png show result]
 [figpng/tst_plt_orca05_stride_08.png show result]
 [figpng/tst_plt_orca05_stride_09.png show result]
 [figpng/tst_plt_orca05_stride_10.png show result]
=== Vertical sections ===

  A quick presentation of vertical sections is shown in [../../Tests/tst_pltz.pro tst_pltz]. After loading any of the grid (for example with one of the above examples). Just try:
  
{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">tst_pltz</strong></span></code></strong>
  </pre>
}}}
''Beware, the command is tst_pltz and not @tst_pltz as tst_pltz.pro is a procedure and not an include.''
  See the results with
  
 * @tst_initlev
 [figpng/tst_pltz_lev_01.png show result]
 [figpng/tst_pltz_lev_02.png show result]
 [figpng/tst_pltz_lev_03.png show result]
 [figpng/tst_pltz_lev_04.png show result]
 [figpng/tst_pltz_lev_05.png show result]
 [figpng/tst_pltz_lev_06.png show result]
 [figpng/tst_pltz_lev_07.png show result]
 [figpng/tst_pltz_lev_08.png show result]
 [figpng/tst_pltz_lev_09.png show result]
 [figpng/tst_pltz_lev_10.png show result]
 [figpng/tst_pltz_lev_11.png show result]
 * @tst_initorca2
 [figpng/tst_pltz_orca2_01.png show result]
 [figpng/tst_pltz_orca2_02.png show result]
 [figpng/tst_pltz_orca2_03.png show result]
 [figpng/tst_pltz_orca2_04.png show result]
 [figpng/tst_pltz_orca2_05.png show result]
 [figpng/tst_pltz_orca2_06.png show result]
 [figpng/tst_pltz_orca2_07.png show result]
 [figpng/tst_pltz_orca2_08.png show result]
 [figpng/tst_pltz_orca2_09.png show result]
 [figpng/tst_pltz_orca2_10.png show result]
 [figpng/tst_pltz_orca2_11.png show result]
 [figpng/tst_pltz_orca2_12.png show result]
 * @tst_initorca05
 [figpng/tst_pltz_orca05_01.png show result]
 [figpng/tst_pltz_orca05_02.png show result]
 [figpng/tst_pltz_orca05_03.png show result]
 [figpng/tst_pltz_orca05_04.png show result]
 [figpng/tst_pltz_orca05_05.png show result]
 [figpng/tst_pltz_orca05_06.png show result]
 [figpng/tst_pltz_orca05_07.png show result]
 [figpng/tst_pltz_orca05_08.png show result]
 [figpng/tst_pltz_orca05_09.png show result]
 [figpng/tst_pltz_orca05_10.png show result]
 [figpng/tst_pltz_orca05_11.png show result]
 [figpng/tst_pltz_orca05_12.png show result]
 * @tst_initlev_stride
 [figpng/tst_pltz_lev_stride_01.png show result]
 [figpng/tst_pltz_lev_stride_02.png show result]
 [figpng/tst_pltz_lev_stride_03.png show result]
 [figpng/tst_pltz_lev_stride_04.png show result]
 [figpng/tst_pltz_lev_stride_05.png show result]
 [figpng/tst_pltz_lev_stride_06.png show result]
 [figpng/tst_pltz_lev_stride_07.png show result]
 [figpng/tst_pltz_lev_stride_08.png show result]
 [figpng/tst_pltz_lev_stride_09.png show result]
 [figpng/tst_pltz_lev_stride_10.png show result]
 [figpng/tst_pltz_lev_stride_11.png show result]
 * @tst_initorca2_stride
 [figpng/tst_pltz_orca2_stride_01.png show result]
 [figpng/tst_pltz_orca2_stride_02.png show result]
 [figpng/tst_pltz_orca2_stride_03.png show result]
 [figpng/tst_pltz_orca2_stride_04.png show result]
 [figpng/tst_pltz_orca2_stride_05.png show result]
 [figpng/tst_pltz_orca2_stride_06.png show result]
 [figpng/tst_pltz_orca2_stride_07.png show result]
 [figpng/tst_pltz_orca2_stride_08.png show result]
 [figpng/tst_pltz_orca2_stride_09.png show result]
 [figpng/tst_pltz_orca2_stride_10.png show result]
 [figpng/tst_pltz_orca2_stride_11.png show result]
 * @tst_initorca05_stride
 [figpng/tst_pltz_orca05_stride_01.png show result]
 [figpng/tst_pltz_orca05_stride_02.png show result]
 [figpng/tst_pltz_orca05_stride_03.png show result]
 [figpng/tst_pltz_orca05_stride_04.png show result]
 [figpng/tst_pltz_orca05_stride_05.png show result]
 [figpng/tst_pltz_orca05_stride_06.png show result]
 [figpng/tst_pltz_orca05_stride_07.png show result]
 [figpng/tst_pltz_orca05_stride_08.png show result]
 [figpng/tst_pltz_orca05_stride_09.png show result]
 [figpng/tst_pltz_orca05_stride_10.png show result]
 [figpng/tst_pltz_orca05_stride_11.png show result]
=== Hovmoellers and time series ===

  A quick presentation of hovmoellers and time series is shown in [../../Tests/tst_pltt.pro tst_pltt]. After loading any of the grid (for example with one of the above examples). Just try:
  
{{{
#!html
<pre xmlns:xl="http://www.w3.org/1999/xlink" class="screen">
  <code class="prompt">idl&gt;</code> <strong class="userinput"><code><span><strong class="command">tst_pltt</strong></span></code></strong>
  </pre>
}}}
''Beware, the command is tst_pltt and not @tst_pltt as tst_pltt.pro is a procedure and not an include.''
  See the results with
  
 * @tst_initlev
 [figpng/tst_pltt_lev_01.png show result]
 [figpng/tst_pltt_lev_02.png show result]
 [figpng/tst_pltt_lev_03.png show result]
 [figpng/tst_pltt_lev_04.png show result]
 [figpng/tst_pltt_lev_05.png show result]
 [figpng/tst_pltt_lev_06.png show result]
 * @tst_initorca2
 [figpng/tst_pltt_orca2_01.png show result]
 [figpng/tst_pltt_orca2_02.png show result]
 [figpng/tst_pltt_orca2_03.png show result]
 [figpng/tst_pltt_orca2_04.png show result]
 [figpng/tst_pltt_orca2_05.png show result]
 [figpng/tst_pltt_orca2_06.png show result]
 * @tst_initorca05
 [figpng/tst_pltt_orca05_01.png show result]
 [figpng/tst_pltt_orca05_02.png show result]
 [figpng/tst_pltt_orca05_03.png show result]
 [figpng/tst_pltt_orca05_04.png show result]
 [figpng/tst_pltt_orca05_05.png show result]
 [figpng/tst_pltt_orca05_06.png show result]
 * @tst_initlev_stride
 [figpng/tst_pltt_lev_stride_01.png show result]
 [figpng/tst_pltt_lev_stride_02.png show result]
 [figpng/tst_pltt_lev_stride_03.png show result]
 [figpng/tst_pltt_lev_stride_04.png show result]
 [figpng/tst_pltt_lev_stride_05.png show result]
 [figpng/tst_pltt_lev_stride_06.png show result]
 * @tst_initorca2_stride
 [figpng/tst_pltt_orca2_stride_01.png show result]
 [figpng/tst_pltt_orca2_stride_02.png show result]
 [figpng/tst_pltt_orca2_stride_03.png show result]
 [figpng/tst_pltt_orca2_stride_04.png show result]
 [figpng/tst_pltt_orca2_stride_05.png show result]
 [figpng/tst_pltt_orca2_stride_06.png show result]
 * @tst_initorca05_stride
 [figpng/tst_pltt_orca05_stride_01.png show result]
 [figpng/tst_pltt_orca05_stride_02.png show result]
 [figpng/tst_pltt_orca05_stride_03.png show result]
 [figpng/tst_pltt_orca05_stride_04.png show result]
 [figpng/tst_pltt_orca05_stride_05.png show result]
 [figpng/tst_pltt_orca05_stride_06.png show result]
=== 1D plots ===

To be continued