Frequently Asked Questions  

- Please ask if there are aspects of LAMP that you cannot understand or find difficult.

1. Where are the monitor spectra?

When data are read in the monitor spectra are assumed to be the first 3 spectra in the raw data. These are stripped out and put into the array n1 for w1, n2 for w2 etc. Each "n" contains all three monitors and its dimensions are (number-of-channels,3). You can see the monitor1 spectrum of workspace 2 by typing: plot,n2(*,0).

2. How does spectrum 1 in LAMP correspond to the order of spectra in the data collection?

In order to simplify plotting runs as surfaces, images and contours, LAMP removes monitors and other "non-detector" spectra from the raw data. Each instrument has its own style in the raw data, and to make things worse the first element in IDL arrays is element number 0.
For IN5 the first LAMP spectrum is instrument-spectrum 9
For IN6 the first LAMP spectrum is instrument-spectrum 7
For IN10 the first LAMP spectrum is instrument-spectrum 1
For IN16 the first LAMP spectrum is instrument-spectrum 1

3. When I press print I only get a PS file.

The LAMP default printer is set in the "Options/Titles.." menu. Press the "Options" button (just above the plot window) followed by "Titles.."  and then enter the desired printer name in the appropriate field. Instrument printers usually have their names on a label somewhere on the printer.

4. Plots are wrong or badly scaled when I use "plot" command in formula entry. (e.g. plot,n1).

The plot-range buttons only apply to workspaces. When you issue the "plot" command manually you must set xrange, yrange and zrange manually. To plot monitor 1 of workspace w3 from 200 to 250 channels: plot,n3(*,1),xrange=[200,250]

5. I see no plot!

The "color" options can be used to plot black-on-black, blue-on-blue etc. A previous user may have made this selection. Also, colour-schemes which are ideal for shaded surfaces may be poor for vectors or contours.

6. LAMP is stuck (no response)

Certain operations on large arrays can take a long time. Contour plots of noisy data are very time-consuming. Using sqw_rebin with small increments also requires patience. If you are convinced that LAMP has gone "dead" then:
Either close the shell window which started LAMP (if you can find it) or.....
a. Select "desktop" from the desk menu at the top left of the screen. You may have to move LAMP or other windows out of the way. With desktop selected take the option "Unix Shell".
b. A new window will open. Type
ps and a list of the processes running will appear. Note the number of the process called IDL.
c. Type "
kill 12345" where in place of 12345 you put the number of the IDL process. If you got it right LAMP will go out!
d. To restart LAMP type "
lamp".

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