.. _cbdm-res-view:

CBDM Results Viewer
===================

Without performing another calculation, the CBDM results viewer allows you to:

  * Change the UDI lux thresholds
  * Change the weather file
  * Export hourly lux values
  * See a weekly, monthly and hourly breakdown
  * Calculate metrics useful for BREEAM

The CBDM Results Viewer is not available for viewing LEED Option 2 results, as
this calculation contains sample data for 4 hours of the year only.

Opening the Viewer
------------------

The **CBDM results viewer** can be accessed via the *Utilities* menu in the *Tas Manager*.

The viewer reads ".tcbdm" files.

UDI Thresholds Button
---------------------

The **Thresholds** button allows you to change the accetable, target and excessive
illuminance levels and see the effect on the results without having to perform the
CBDM calculation again.

  .. image:: images/Thresholds.png

Display Hours Button
--------------------

The **Display Hours** button allows you to view the results excluding certain
periods from the calculation; for example, you may wish to view the monthly average
bar charts but only for hours where the sun is low in the sky.

  .. warning::
      Including hours that the calculation was not originally performed for is not
      possible, so be careful not to include any hours that were not in the original
      calculation.

You can also change the timestep and see the effect on the results.

Weather Button
--------------

The **Weather** button allows you to change the weather data associated with the
calculation. This is useful if you want to compare future weather data with current
weather data. Though it is possible to use weather data with a different longitude
and lattitude to the original calculation, it is not recommended as the results will
be invalid.

Result Breakdown
----------------

You can use the CBDM results viewer to examine when the lux levels for a zone
are within the various UDI bands by selecting the zone from the zone selection
dropdown and examining the bar chart:

  .. image:: images/zone_dropdown_viewer.png

You can choose to see monthly average, weekly average or hourly results:

  .. image:: images/viewer_breakdown.png

You can zoom into a particular area by clicking and dragging in the bar chart:

  .. image:: images/viewer_drag_zoom.png

In the example below, we can interrogate the results for a particular date (3rd August):

  .. image:: images/viewer_aug_3rd.png

We can see that some proportion of the points are almost always excessively bright, regardless
of the hour of the day. We can also see that there are very few points that not lit well enough.

Exporting Data
--------------
To export annual data , press the **Export** button:

  .. image:: images/export.png


The following information is exported:
  * Average lux
  * Average Daylight Factors
  * Minimum Lux (individual point)
  * Maximum Lux (individual point)

The results will be exported according to the timestep currently selected in the
*Displayed Hours* window. 

Other Metrics (e.g. BREEAM)
---------------------------
Clicking the **Analyse** button allows you to calculate the *Average Daylight
Illuminance* and *Minimum Daylight Illuminance* in terms of lux levels and a
target number of hours per year.

For example, for certain BREEAM credits its useful to determine what percentage
of the space receives at least X lux for Y hours per year or more.

.. image:: images/Analyse.png

A report of this information can be generated by pressing the **Report** button
on this dialog.