---json
{
    "description": "This how-to shows you how to generate data that follows a normal distribution with the column histogram generator",
    "low_quality_page": "false",
    "page_id": "wllpdo8jabagb71rrlmkp",
    "title": "How to generate a normal distribution with an histogram generator"
}
---
====== Tabulify - How to generate a normal distribution with an histogram generator ======

===== About =====
This [[..:howto|how-to]] shows you how to generate data that follows a [[datacadamia>normal_distribution|normal distribution]] with the [[docs:generator:histogram|column histogram generator]].

===== Steps =====

==== Defining the buckets ====



The [[docs:generator:histogram#buckets|bucket list]] needs a serie of value and their respective factor.

We will simulate the arrival of people at an event.

The time will be the value and the factor will follow the probability of the normal distribution.

Example:
The below bucket definition:
<code yaml>
Buckets:
  "8:45": 0.05
  "8:50": 0.5
  "8:55": 0.22
  "9:00": 0.4
  "9:05": 0.22
  "9:10": 0.5
  "9:15": 0.05
</code>
models the below normal distribution:

{{howto:generator:normal_distribution_incoming_time_meeting.png|}}

==== Creation of the generator file ====
To generate data, you need to create a [[docs:resource:generator|generator file]] that will describe the data to be generated.

The below [[docs:resource:generator|data resource generator]]:
  * has the [[docs:resource:name|name]] ''histogram_normal_distribution--datagen.yml''
  * has the [[docs:resource:logicalname|logical name]] ''histogram_normal_distribution''
  * will generate ''30'' values (''MaxRecordCount'' count)
  * has a column named ''id'' that has [[docs:generator:sequence|sequence data generator]] that:
      * starts by default at the value ''1''
      * increments by default with the value ''1''
  * has a column named ''buckets_map'' with a [[docs:generator:histogram|histogram generator]] where the ''buckets'' property defines a map where:
      * the key is the value to generate
      * the value is the chance factor of generation:
          * the more, the more chance that you get the value generated
          * this is the equivalent of the probability value of the distribution.

<unit>
<file yaml histogram_normal_distribution--datagen.yml>
MaxRecordCount: 30
Columns:
  - name: id
    type: integer
    comment: A id column to see easily the number of values generated
    DataGenerator:
      type: sequence
  - name: bucket_map
    type: time
    comment: A column with a histogram generator that generates an uniform distribution of time
    DataGenerator:
      type: histogram
      Buckets:
        "8:45": 0.05
        "8:50": 0.5
        "8:55": 0.22
        "9:00": 0.4
        "9:05": 0.22
        "9:10": 0.5
        "9:15": 0.05

</file>
</unit>
==== Printing the data ====

With the [[docs:tabli:data:print|data print command]], we can print the ''30 values'' generated.
<unit>
<code dos>
tabli data print histogram_normal_distribution--datagen.yml@howto
</code>
<note tip>
[[docs:connection:howto|howto]] is the connection that contains the files used in the [[..:howto|HowTo's]].
</note>
<console>
id   bucket_map
--   ----------
 1   08:45:00
 2   09:15:00
 3   09:05:00
 4   09:05:00
 5   08:50:00
 6   09:00:00
 7   08:50:00
 8   09:05:00
 9   09:05:00
10   08:45:00
11   08:50:00
12   08:55:00
13   09:15:00
14   08:50:00
15   08:55:00
16   09:15:00
17   08:50:00
18   08:50:00
19   09:05:00
20   09:00:00
21   09:10:00
22   08:50:00
23   08:50:00
24   09:10:00
25   09:05:00
26   09:10:00
27   09:00:00
28   09:15:00
29   09:05:00
30   09:05:00
</console>
</unit>
===== Next =====



Because a [[docs:resource:generator|generator]] is just a [[docs:resource:resource|data resource]], you can use it in every [[docs:op:op|data operation]].

<btn>
[[generator_data_operation|How to use a generator in a data operation ]]
</btn>