Tutorial example 2
------------------

Next example includes every important elements for minimum usage of ANGEL . If you have no time to have a read the following manual through, it is enough to learn this example for starting ANGEL . We show an input file and output graph in the following.

.. rubric:: List 1.2  • Input of tutorial example 2
   :name: list-1-2
   :class: angel-list-caption

.. code-block:: text

        1:  'Figure 2'                                          --- (1)
        2:  X: E (MeV)                                          --- (2)
        3:  Y: d\sigma/d\OmegadE (nb/MeV/sr)                    --- (3)
        4:  W:Comment = ^{12}C + ^{40}Ca/ X(1) Y(65)             --- (4)
        5:  A: X(4.3) Y(65) AX(5.5) AY(53)                      --- (5)
        6:  AW:Arrow/ X(4.5) Y(23) AX(4) AY(10)                 --- (6)
        7:  H:  X   Y(Histogram),DH0                            --- (7)
        8:      0.0    0
        9:      0.5   10
       10:      1.5   20
       11:      2.5   35
       12:      3.5   30
       13:      4.5   45
       14:      5.5   70
       15:      6.5    0
       16:  H: X  Y(Spline),SL5                                 --- (8)
       17:    0.5   40
       18:    4     10
       19:    6     20
       20:    7     60
       21:  H: X   DX    Y(Error bar),N3    D                   --- (9)
       22:     2    1         50           10

.. figure:: assets/fig102.png
   :name: fig-intro-2
   :align: center
   :class: responsive-figure
   :width: 386.8pt

   Tutorial example 2

You can see a high quality image produced from a simple input by ANGEL . First, let me explain the points denoted by number in right-hand side of input lines in List 1.2.

#. | Title of graph ``'   '``
   | The title of graph is specified between ``'   '``. This is shown in the middle upside the graph frame. The title can be removed and moved to horizontal direction by the parameter.

#. | Title of X axis ``X:``
   | The title of X axis is defined by the line started from ``X:``. You can use italic, bold, special characters, and other various expression of the characters in the title and also in any line of string.

#. | Title of Y axis ``Y:``
   | The title of Y axis is defned by the line started from ``Y:``.

#. | Comment ``W:``
   | The comment in the figure is defined by the line started from ``W:``. The strings from ``W:`` to ``/`` are shown in the figure at the point specified by ``X(  ) Y(  )`` as a comment.

#. | Arrow ``A:``
   | The arrow in the figure is defined by the line started from ``A:``. The start and end points of the arrow are specified by ``X(  ) Y(  )`` and ``AX(  ) AY(  )``, respectively.

#. | Arrow with Comment ``AW:``
   | This is a combination of arrow and comment. The strings from ``AW:`` to ``/`` are shown in the figure at the point specified by ``X(  ) Y(  )`` and the arrow is described to ``AX(  ) AY(  )``.

In the following sections, we will explain another parameters which define the more detail of the above objects.

Next, we explain the basic section in ANGEL , ``H:``, which defines the x-y graph. There are three ``H:`` sections (7), (8) and (9) in this example. The main purpose of this line of ``H:`` is to define the ordering of the following columns. As shown in the previous example, if the numerical data consist of x-value and y-value columns, we should write ``H: X  Y``. By this line, we can additionally define line type, symbol type, color, and legend.

The strings in the parenthesis after ``Y`` like ``Y(Histogram),DH0`` are automatically shown in the right hand side of the graph frame as legends. The strings after the comma define the line type (``D`` = Dashed Line, ``L`` = Solid Line, ``N`` = No Line), spline (``S`` = Spline), histogram (``H`` = Histogram), and symbol type (``0`` = No Symbol, ``3`` = Open Circle).

In the last section of (9), there are columns defined by ``DX, D``. These define the error bars. ``DX`` defines the error bar of the X column, ``D`` defines the error bar of the Y column just before. In default, the value of the error is the same values around the y-value. It is explicitly expressed by ``D+-``. If you want to define the different error values upper and lower values around the y-value, you should define those by different columns like ``D+  D-``.

In ANGEL , we call ’section’ the part of the input file starting from alphabet characters with colon ``:`` like ``AW: H:``.