---
myst:
    substitutions:
        bloc:
            python: 6-8
            cpp: 4-6
---
# Graph 2D "pairs"

This 2D graph consists in creating a matrix of graphs, where for the (i,j) cells with i different 
from j, the graph contains the scatterplot of the attribute j versus the attribute i, and for cell 
(i,i), the graph contains the histogram of the attribute i.

{{                                                                                                  
    "```{literalinclude} " + parent_dir                                                             
    + "/roottest/uranie/doc/dataserver/vizualisation/" + language + "/code_geyser_pairs." 
    + extension + "\n"
    + ":language: " + language + "\n"
    + ":lines: " + bloc[language] + "\n"                                                   
    + "```"                                                                                         
}}  

{{                                                                                                  
    "```{" "figure" "} " + parent_dir +                                                             
        "/usermanual/dataserver/figures/geyser_pairs.png\n"     
    ":align: center\n"                                                                              
    ":name: dataserver_geyser_pairs\n"                                            
    + figure_scale + "\n"                                                                
    "\n"                                                                                            
    'Graphs of "Pairs" of the ' + tds + " `geyser`\n" 
    "```"                                                                                           
}}

````{admonition} Summary: 2D Graph

- `drawScatterplot` (__const char*__ varexp, __const char*__ selection="", __Option_t*__ option="")

    Draw 2D graph with the number of points of attributes located in *varexp* on the background.

- `drawProfile` (__const char*__ varexp, __const char*__ selection="", __Option_t*__ option="")

    Draw 2D graphic of the mean and standard deviation of each segment of "X" axis for the attributes 
    contained in *varexp*.

    ```{tip}
    The possible values of options *option* are:

    __nclass=[0-9]*__
    : Specifies the number of segments in "X" axis .

    **same**
    : Displays the 2D scatterplot below "profile".
    ```

- `drawTufte` (__const char*__ varexp, __const char*__ selection="", __Option_t*__ option="")

    Draw 2D graph of the attributes located in <emphasis>varexp</emphasis>.

    ```{tip}
    The possible values of options *option* are:

    **optstat**
    : Prints the window containing statistics in each histogram

    **scatter**
    : Prints the scatterplot the same way as the command 
      [drawScatterplot](#dataserver_vizualisation_2d_contour_levels).
    ```

- `drawPairs` (__const char*__ varexp, __const char*__ selection="", __Option_t*__ option="")

    Create the matrix of graph with the attributes located in *varexp*.

It should be noticed that these functions have the same signature as the `draw` method of a 
**TTree** of {{root}}.

```{warning}
For all these methods, the character *varexp* must contain either two attributes or a single 
character ":"
```
````