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[BubbleCat]

I am looking if anyone can point me to a software (probably image manipulation software) that will let me not only perform integration on existing graphs but also addition and multiplication of graphs. Or any way to do it.

Reason as follows: Lamps once again. Many lamps are described with a graph showing its radiation intensity for the range of wavelength, but not photosynthetic active radiation. Now the only way to determine the later mathematically, appears to me: Obtain images of both, the lamps radiance / wavelength and a plants photosynthetic activity / wavelength. Scale both in one direction, ensuring the scales for wavelength match. Next the lamps chart would have to be scaled to suit its wattage or lumens, power of radiation depends on its wavelength, so the only way to scale it would again be multiplication of graphs or graph and function, not simple integration. It must of course be scaled to allow comparison between lamps.

Whoever read to here gets the idea anyway: A software is needed, that first allows me to perform multiplication on graphs that I only have a visual representation, but not the actual function and later performs integration. Thanks

1 Like Mangrove likes this.

[Psylocke]

Google "digitization graph free"

Lots of stuff comes up. I've done this in the past, but can't remember what I used.

1 Like BubbleCat likes this.

[BubbleCat]

In case someone else will ever ask the same:

Came up with this list:

Trials & payware:
http://www.getdata-graph-digitizer.com/registration.php
http://xyextract-graph-digitizer.soft112.com/
http://www.softpedia.com/get/Multimedia/Graphic/Graphic-Others/GetData-Graph-Digitizer.shtml
http://www.digitizeit.de/index.html

Free & open-source:
http://sourceforge.net/projects/plotdigitizer/
http://markummitchell.github.io/engauge-digitizer/
http://sourceforge.net/projects/graphdataextrac/

https://sourceforge.net/projects/autotrace/ ?

Obviously since all of the first group are paid for, some Windows only and appear poorly written I will try the later two and update accordingly.

[Mangrove]

I am looking if anyone can point me to a software (probably image manipulation software) that will let me not only perform integration on existing graphs but also addition and multiplication of graphs. Or any way to do it.

Reason as follows: Lamps once again. Many lamps are described with a graph showing its radiation intensity for the range of wavelength, but not photosynthetic active radiation. Now the only way to determine the later mathematically, appears to me: Obtain images of both, the lamps radiance / wavelength and a plants photosynthetic activity / wavelength. Scale both in one direction, ensuring the scales for wavelength match. Next the lamps chart would have to be scaled to suit its wattage or lumens, power of radiation depends on its wavelength, so the only way to scale it would again be multiplication of graphs or graph and function, not simple integration. It must of course be scaled to allow comparison between lamps.

Whoever read to here gets the idea anyway: A software is needed, that first allows me to perform multiplication on graphs that I only have a visual representation, but not the actual function and later performs integration. Thanks

Have you ever heard of these things called calculus, differential equations, electrostatics, physics, electrodynamics, spreadsheet software, khan academy, This Free graphing calculator, etc? They may be of use to you

[Mangrove]

Have you ever tried to contact the manufacturer of your lamps and asked for the raw data used to compute their graphs?? Just pretend to be an electrical engineer in any emails you send them; that should be enough clout to score you some raw data

[BubbleCat]

Yo dawg !

You are assuming that I do have the raw data, either pairs of values or functions. In that case I'd not have to loose a single word about it, but just multiply and integrate. What I am trying: Extrapolate raw data from visualization.

[Mangrove]

Yo dawg !

You are assuming that I do have the raw data, either pairs of values or functions. In that case I'd not have to loose a single word about it, but just multiply and integrate. What I am trying: Extrapolate raw data from visualization.

I'm trying to suggest that it would be a lot easier if you managed to obtain the raw data (ideally as a spreadsheet) from the manufacturer themselves, as trying to manipulate data in the form of a graph is a pain right in the arseschwitz (plus, IME it's practically impossible to manipulate graphs of data themselves unless one has the actual raw data itself; graphs and stats can be easily manipulated; raw data less so).

I love my data raw; I find that any processing and manipulation of it whatsoever offsets its flavor/values ad nauseam and ad absurdum.