# Graph values from a selectable list of records from another table

**MatthewDeady**Jul 17, 2012 1:39 PM

### Title

Graph values from a selectable list of records from another table

### Post

Hello all, first post.

I'm creating a database that will contain data for numerous lasers made by the company. These lasers vary in frequency range. I'd like to overlay their frequencies ontop of a graph of the atmospheric transmittance.

My tables with relevant fields are as follows (QCL stands for Quantum Cascade Laser):

qcls

_id : primary key

frequency_low : Number - the low end of the range of frequencies achievable by this laser

frequency_high : Number - the high end "

atmospheric_data

_id : primary key

qcl_id : Number - Global foreign key to a qcl, I'd like to make this a list of values. Currently I use this to select a single QCL to graph.

wave_number : Number - the x-axis of the graph. These numbers multiplied by 0.03 give the frequency in THz, which are the same units in qcls::frequency_low and high.

transmittance : Number - The y-axis of the graph. The ratio of transmitted light to incident. a value of 0.75 means 75% of the light is transmitted through the atmosphere. These values come from published literature.

frequency_indicator : Calculation - 1 or 0. Here's my current calculation:

(qcls::frequency_high + qcls::frequency_low)/2 ≥ wave_number * .03

and

(qcls::frequency_high + qcls::frequency_low)/2 < GetNthRecord ( wave_number ; Get ( RecordNumber ) +1) * .03)

it basically says, if the average of the QCL's frequency range falls between this record and the next, it's 1, otherwise 0. This has the effect of giving a vertical line on the graph where a QCL's average frequency lies so we can see how that fits with the atmospheric transmittance signature.

minimum, maximum : Number - these two fields indicate the range of the spectrum the user wants to graph.

I'd like to be able to define which QCLs are taken into account by the frequency_indicator field. I'd like to have a list next to my graph where you could go through and press a button to have a laser's average frequency indicated on the graph, and a button at top to include/exclude all. Lastly, I'd like to have the indication of which QCLs to graph be client-based so more than one person can operate the database at one time and each person select a different list of QCLs.

Any ideas? I've been bashing my head against the wall on this for a while now. Thanks so much for any help.