Overlaying photometric flux points onto a 1d spectrum.

nrowell wrote on Aug 24, 2007

Hi,
I'm having trouble plotting some data. I have a flux calibrated 1d spectrum, which plots fine, plus i have three band photometry which i've converted to approximate fluxes at the central wavelengths of each band pass. I'm trying to plot these three points (with error bars) on top of the spectrum, and getting nowhere. Can anyone suggest a way to do this?
Cheers,
Nick Rowell

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Mike Fitzpatrick wrote on Aug 24, 2007

There's no one task that takes a spectrum and a set of fluxes/error to create the specific plot you want, but it can easily be done in layers and by appending to the graph. For example, the WSPECTEXT or LISTPIXELS task can create a list of wavelength value pairs you'd feed to the GRAPH task to create the initial plot.
You could call GRAPH again to plot the three flux points with markers (turn on the 'point' parameter) and then complete it by again calling GRAPH to draw lines for the error bars. Nominally you'd want to write a script to simplify this process (see the Docs page for the sript manual).

Other tasks that you could use would be IGI or SGRAPH assuming you STSDAS installed. IGI is a Mongo-like language that could do this easily, SGRAPH is like graph but has direct support for error bars. Hope this helps.

Cheers,
-Mike

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nrowell wrote on Aug 24, 2007

Cheers Mike, that's sorted it.
Nick Rowell

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Last post on Aug 24, 2007